feat: replace amqp connection

audit/api/api_legacy_dynamic_test.go

@@ -30,7 +30,11 @@ func TestDynamicLegacyAuditApi(t *testing.T) {
 	defer solaceContainer.Stop()
 
 	// Instantiate the messaging api
-	messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConfig{URL: solaceContainer.AmqpConnectionString})
+	messagingApi, err := messaging.NewAmqpApi(
+		messaging.AmqpConnectionPoolConfig{
+			Parameters: messaging.AmqpConnectionConfig{BrokerUrl: solaceContainer.AmqpConnectionString},
+			PoolSize:   1,
+		})
 	assert.NoError(t, err)
 
 	// Validator

audit/api/api_legacy_test.go

@@ -32,7 +32,10 @@ func TestLegacyAuditApi(t *testing.T) {
 	defer solaceContainer.Stop()
 
 	// Instantiate the messaging api
-	messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConfig{URL: solaceContainer.AmqpConnectionString})
+	messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConnectionPoolConfig{
+		Parameters: messaging.AmqpConnectionConfig{BrokerUrl: solaceContainer.AmqpConnectionString},
+		PoolSize:   1,
+	})
 	assert.NoError(t, err)
 
 	// Validator
@@ -579,7 +582,10 @@ func TestLegacyAuditApi_NewLegacyAuditApi(t *testing.T) {
 		defer solaceContainer.Stop()
 
 		// Instantiate the messaging api
-		messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConfig{URL: solaceContainer.AmqpConnectionString})
+		messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConnectionPoolConfig{
+			Parameters: messaging.AmqpConnectionConfig{BrokerUrl: solaceContainer.AmqpConnectionString},
+			PoolSize:   1,
+		})
 		assert.NoError(t, err)
 
 		// Validator

audit/api/api_routable_test.go

@@ -33,7 +33,10 @@ func TestRoutableAuditApi(t *testing.T) {
 	defer solaceContainer.Stop()
 
 	// Instantiate the messaging api
-	messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConfig{URL: solaceContainer.AmqpConnectionString})
+	messagingApi, err := messaging.NewAmqpApi(messaging.AmqpConnectionPoolConfig{
+		Parameters: messaging.AmqpConnectionConfig{BrokerUrl: solaceContainer.AmqpConnectionString},
+		PoolSize:   1,
+	})
 	assert.NoError(t, err)
 
 	// Validator

audit/messaging/amqp_config.go

@@ -0,0 +1,15 @@
+package messaging
+
+const AmqpTopicPrefix = "topic://"
+const connectionTimeoutSeconds = 10
+
+type AmqpConnectionConfig struct {
+	BrokerUrl string `json:"brokerUrl"`
+	Username  string `json:"username"`
+	Password  string `json:"password"`
+}
+
+type AmqpConnectionPoolConfig struct {
+	Parameters AmqpConnectionConfig `json:"parameters"`
+	PoolSize   int                  `json:"poolSize"`
+}

audit/messaging/amqp_connection.go

@@ -0,0 +1,277 @@
+package messaging
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/Azure/go-amqp"
+	"log/slog"
+	"sync"
+	"time"
+)
+
+var ConnectionClosedError = errors.New("amqp connection is closed")
+
+type AmqpConnection struct {
+	connectionName string
+	lock           sync.RWMutex
+	brokerUrl      string
+	username       string
+	password       string
+	conn           amqpConn
+	dialer         amqpDial
+}
+
+// amqpConn is an abstraction of amqp.Conn
+type amqpConn interface {
+	NewSession(ctx context.Context, opts *amqp.SessionOptions) (amqpSession, error)
+	Close() error
+	Done() <-chan struct{}
+}
+
+type defaultAmqpConn struct {
+	conn *amqp.Conn
+}
+
+func newDefaultAmqpConn(conn *amqp.Conn) *defaultAmqpConn {
+	return &defaultAmqpConn{
+		conn: conn,
+	}
+}
+
+func (d defaultAmqpConn) NewSession(ctx context.Context, opts *amqp.SessionOptions) (amqpSession, error) {
+	session, err := d.conn.NewSession(ctx, opts)
+	if err != nil {
+		return nil, err
+	}
+	return newDefaultAmqpSession(session), nil
+}
+
+func (d defaultAmqpConn) Close() error {
+	return d.conn.Close()
+}
+
+func (d defaultAmqpConn) Done() <-chan struct{} {
+	return d.conn.Done()
+}
+
+var _ amqpConn = (*defaultAmqpConn)(nil)
+
+type amqpDial interface {
+	Dial(ctx context.Context, addr string, opts *amqp.ConnOptions) (amqpConn, error)
+}
+
+type amqpSession interface {
+	NewSender(ctx context.Context, target string, opts *amqp.SenderOptions) (amqpSender, error)
+	Close(ctx context.Context) error
+}
+
+type defaultAmqpSession struct {
+	session *amqp.Session
+}
+
+func newDefaultAmqpSession(session *amqp.Session) *defaultAmqpSession {
+	return &defaultAmqpSession{
+		session: session,
+	}
+}
+
+func (s *defaultAmqpSession) NewSender(ctx context.Context, target string, opts *amqp.SenderOptions) (amqpSender, error) {
+	return s.session.NewSender(ctx, target, opts)
+}
+
+func (s *defaultAmqpSession) Close(ctx context.Context) error {
+	return s.session.Close(ctx)
+}
+
+var _ amqpSession = (*defaultAmqpSession)(nil)
+
+type defaultAmqpDialer struct{}
+
+func (d *defaultAmqpDialer) Dial(ctx context.Context, addr string, opts *amqp.ConnOptions) (amqpConn, error) {
+	dial, err := amqp.Dial(ctx, addr, opts)
+	if err != nil {
+		return nil, err
+	}
+	return newDefaultAmqpConn(dial), nil
+}
+
+var _ amqpDial = (*defaultAmqpDialer)(nil)
+
+func NewAmqpConnection(config *AmqpConnectionConfig, connectionName string) *AmqpConnection {
+	return &AmqpConnection{
+		connectionName: connectionName,
+		lock:           sync.RWMutex{},
+		brokerUrl:      config.BrokerUrl,
+		username:       config.Username,
+		password:       config.Password,
+		dialer:         &defaultAmqpDialer{},
+	}
+}
+
+func (c *AmqpConnection) NewSender(ctx context.Context, topic string) (*AmqpSenderSession, error) {
+	if c.conn == nil {
+		return nil, errors.New("connection is not initialized")
+	}
+
+	if c.internalIsClosed() {
+		return nil, ConnectionClosedError
+	}
+
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	// new session
+	newSession, err := c.conn.NewSession(ctx, nil)
+	if err != nil {
+		return nil, fmt.Errorf("new session: %w", err)
+	}
+
+	// new sender
+	newSender, err := newSession.NewSender(ctx, topic, nil)
+	if err != nil {
+		err = fmt.Errorf("new internal sender: %w", err)
+
+		closeErr := newSession.Close(ctx)
+		if closeErr != nil {
+			return nil, errors.Join(err, fmt.Errorf("close session: %w", closeErr))
+		}
+		return nil, err
+	}
+
+	return &AmqpSenderSession{newSession, newSender}, nil
+}
+
+func (c *AmqpConnection) ResetConnectionAndRetryIfErrorWithReturnValue(opName string, fn func(ctx context.Context) (any, error)) (any, error) {
+	ctx, cancelFn := context.WithTimeout(context.Background(), 10*time.Second)
+	result, err := fn(ctx)
+	cancelFn()
+
+	if err != nil {
+		slog.Info(fmt.Sprintf("amqp connection: %s", opName), slog.Any("connection", c.connectionName), slog.Any("err", err))
+		err := c.ResetConnection(context.Background())
+		if err != nil {
+			return nil, fmt.Errorf("reset connection: %w", err)
+		}
+
+		newCtx, closeFn := context.WithTimeout(context.Background(), 10*time.Second)
+		defer closeFn()
+
+		// Retry
+		return fn(newCtx)
+	}
+	return result, nil
+}
+
+func (c *AmqpConnection) ResetConnection(ctx context.Context) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	err := c.internalClose()
+	if err != nil {
+		slog.Warn("amqp connection: reset: failed to close amqp connection", slog.Any("err", err))
+	}
+
+	subCtx, cancel := context.WithTimeout(ctx, connectionTimeoutSeconds*time.Second)
+	err = c.internalConnect(subCtx)
+	cancel()
+	if err != nil {
+		slog.Warn("amqp connection: reset: failed to connect to amqp server, retry..", slog.Any("err", err))
+		subCtx, cancel = context.WithTimeout(ctx, connectionTimeoutSeconds*time.Second)
+		err = c.internalConnect(subCtx)
+		cancel()
+		if err != nil {
+			return fmt.Errorf("connect: %w", err)
+		}
+	}
+	return nil
+}
+
+func As[T any](value any, err error) (*T, error) {
+	if err != nil {
+		return nil, err
+	}
+	if value == nil {
+		return nil, nil
+	}
+	castedValue, isType := value.(*T)
+	if !isType {
+		return nil, fmt.Errorf("could not cast value: %T", value)
+	}
+	return castedValue, nil
+}
+
+func (c *AmqpConnection) Connect() error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	subCtx, cancel := context.WithTimeout(context.Background(), connectionTimeoutSeconds*time.Second)
+	defer cancel()
+
+	if err := c.internalConnect(subCtx); err != nil {
+		return fmt.Errorf("internal connection connect: %w", err)
+	}
+	return nil
+}
+
+func (c *AmqpConnection) internalConnect(ctx context.Context) error {
+	if c.conn == nil {
+		// Set credentials if specified
+		auth := amqp.SASLTypeAnonymous()
+		if c.username != "" && c.password != "" {
+			auth = amqp.SASLTypePlain(c.username, c.password)
+		} else {
+			slog.Debug("amqp connection: connect: using anonymous messaging")
+		}
+		options := &amqp.ConnOptions{
+			SASLType: auth,
+		}
+
+		// Initialize connection
+		conn, err := c.dialer.Dial(ctx, c.brokerUrl, options)
+		if err != nil {
+			return fmt.Errorf("dial: %w", err)
+		}
+		c.conn = conn
+	}
+	return nil
+}
+
+func (c *AmqpConnection) Close() error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if err := c.internalClose(); err != nil {
+		return fmt.Errorf("close: %w", err)
+	}
+	return nil
+}
+
+func (c *AmqpConnection) internalClose() error {
+	if c.conn != nil {
+		if err := c.conn.Close(); err != nil {
+			return fmt.Errorf("internal connection close: %w", err)
+		}
+		c.conn = nil
+	}
+	return nil
+}
+
+func (c *AmqpConnection) IsClosed() bool {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	return c.internalIsClosed()
+}
+
+func (c *AmqpConnection) internalIsClosed() bool {
+	if c.conn == nil {
+		return true
+	}
+	select {
+	case <-c.conn.Done():
+		return true
+	default:
+		return false
+	}
+}

audit/messaging/amqp_connection_pool.go

@@ -0,0 +1,213 @@
+package messaging
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"sync"
+)
+
+type connectionProvider interface {
+	NewAmqpConnection(config *AmqpConnectionConfig, connectionName string) *AmqpConnection
+}
+
+type defaultAmqpConnectionProvider struct{}
+
+func (p defaultAmqpConnectionProvider) NewAmqpConnection(config *AmqpConnectionConfig, connectionName string) *AmqpConnection {
+	return NewAmqpConnection(config, connectionName)
+}
+
+var _ connectionProvider = (*defaultAmqpConnectionProvider)(nil)
+
+type ConnectionPool interface {
+	Close() error
+	NewHandle() *ConnectionPoolHandle
+	GetConnection(handle *ConnectionPoolHandle) (*AmqpConnection, error)
+}
+
+type AmqpConnectionPool struct {
+	config             AmqpConnectionPoolConfig
+	connectionName     string
+	connections        []*AmqpConnection
+	connectionProvider connectionProvider
+	handleOffset       int
+	lock               sync.RWMutex
+}
+
+type ConnectionPoolHandle struct {
+	connectionOffset int
+}
+
+func NewAmqpConnectionPool(config AmqpConnectionPoolConfig, connectionName string) (ConnectionPool, error) {
+	pool := &AmqpConnectionPool{
+		config:             config,
+		connectionName:     connectionName,
+		connections:        make([]*AmqpConnection, 0),
+		connectionProvider: defaultAmqpConnectionProvider{},
+		handleOffset:       0,
+		lock:               sync.RWMutex{},
+	}
+
+	if err := pool.initializeConnections(); err != nil {
+		if closeErr := pool.Close(); closeErr != nil {
+			return nil, errors.Join(err, fmt.Errorf("initialize amqp connection: pool closed: %w", closeErr))
+		}
+		return nil, fmt.Errorf("initialize connections: %w", err)
+	}
+
+	return pool, nil
+}
+
+func (p *AmqpConnectionPool) initializeConnections() error {
+	if len(p.connections) < p.config.PoolSize {
+		p.lock.Lock()
+		defer p.lock.Unlock()
+
+		numMissingConnections := p.config.PoolSize - len(p.connections)
+
+		for i := 0; i < numMissingConnections; i++ {
+			if err := p.internalAddConnection(); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (p *AmqpConnectionPool) internalAddConnection() error {
+	newConnection, err := p.internalNewConnection()
+	if err != nil {
+		return fmt.Errorf("new connection: %w", err)
+	}
+	p.connections = append(p.connections, newConnection)
+	return nil
+}
+
+func (p *AmqpConnectionPool) internalNewConnection() (*AmqpConnection, error) {
+	conn := p.connectionProvider.NewAmqpConnection(&p.config.Parameters, p.connectionName)
+	if err := conn.Connect(); err != nil {
+		slog.Warn("amqp connection: failed to connect to amqp broker", slog.Any("err", err))
+
+		// retry
+		if err = conn.Connect(); err != nil {
+			connectErr := fmt.Errorf("failed to connect to amqp broker: %w", err)
+			if closeErr := conn.Close(); closeErr != nil {
+				// this case should never happen as the inner connection should always be null, therefore
+				// it should not have to be closed, i.e. be able to return errors.
+				return nil, errors.Join(connectErr, fmt.Errorf("close connection: %w", closeErr))
+			}
+			return nil, connectErr
+		}
+	}
+	return conn, nil
+}
+
+func (p *AmqpConnectionPool) Close() error {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	closeErrors := make([]error, 0)
+	for _, conn := range p.connections {
+		if err := conn.Close(); err != nil {
+			closeErrors = append(closeErrors, fmt.Errorf("connection: close: %w", err))
+		}
+	}
+	p.connections = make([]*AmqpConnection, 0)
+	if len(closeErrors) > 0 {
+		return errors.Join(closeErrors...)
+	}
+	return nil
+}
+
+func (p *AmqpConnectionPool) NewHandle() *ConnectionPoolHandle {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	offset := p.handleOffset
+	p.handleOffset += 1
+
+	offset = offset % p.config.PoolSize
+
+	return &ConnectionPoolHandle{
+		connectionOffset: offset,
+	}
+}
+
+func (p *AmqpConnectionPool) GetConnection(handle *ConnectionPoolHandle) (*AmqpConnection, error) {
+	// get the requested connection or another one
+	conn, addConnection := p.nextConnectionForHandle(handle)
+
+	// renew the requested connection if the request connection is closed
+	if conn == nil || addConnection {
+		p.lock.Lock()
+
+		// check that accessing the pool only with a valid index (out of bounds should only occur on shutdown)
+		if handle.connectionOffset < len(p.connections) && p.connections[handle.connectionOffset] == nil {
+			connection, err := p.internalNewConnection()
+			if err != nil {
+				if conn == nil {
+					// case: connection could not be renewed and no connection to return has been found
+					p.lock.Unlock()
+					return nil, fmt.Errorf("renew connection: %w", err)
+				}
+
+				// case: connection could not be renewed but another connection will be returned
+				slog.Warn("amqp connection pool: get connection: renew connection: ", slog.Any("err", err))
+			} else {
+				// case: connection could be renewed and will be added to pool
+				p.connections[handle.connectionOffset] = connection
+				conn = connection
+			}
+		}
+		p.lock.Unlock()
+	}
+
+	return conn, nil
+}
+
+func (p *AmqpConnectionPool) nextConnectionForHandle(handle *ConnectionPoolHandle) (*AmqpConnection, bool) {
+	// return the next possible index (including the retry offset)
+	nextIndex := func(idx int) int {
+		if idx+handle.connectionOffset >= p.config.PoolSize {
+			return (idx + handle.connectionOffset) % p.config.PoolSize
+		} else {
+			return idx + handle.connectionOffset
+		}
+	}
+
+	// retry as long as there are remaining connections in the pool
+	var conn *AmqpConnection
+	var addConnection bool
+	for i := 0; i < p.config.PoolSize; i++ {
+
+		// get the next possible connection (considering the retry index)
+		idx := nextIndex(i)
+		p.lock.RLock()
+		if idx < len(p.connections) {
+			conn = p.connections[idx]
+		} else {
+			//  handle the edge case that the pool is empty on shutdown
+			conn = nil
+		}
+		p.lock.RUnlock()
+
+		// remember that the requested is closed, retry with the next
+		if conn == nil {
+			addConnection = true
+			continue
+		}
+
+		// if the connection is closed, mark it by setting it to nil
+		if conn.IsClosed() {
+			p.lock.Lock()
+			p.connections[idx] = nil
+			p.lock.Unlock()
+
+			addConnection = true
+			continue
+		}
+
+		return conn, addConnection
+	}
+	return nil, true
+}

audit/messaging/amqp_connection_pool_test.go

@@ -0,0 +1,572 @@
+package messaging
+
+import (
+	"errors"
+	"fmt"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"sync"
+	"testing"
+)
+
+type connectionProviderMock struct {
+	mock.Mock
+}
+
+func (p *connectionProviderMock) NewAmqpConnection(config *AmqpConnectionConfig, connectionName string) *AmqpConnection {
+	args := p.Called(config, connectionName)
+	return args.Get(0).(*AmqpConnection)
+}
+
+var _ connectionProvider = (*connectionProviderMock)(nil)
+
+func Test_AmqpConnectionPool_GetHandle(t *testing.T) {
+
+	t.Run("next handle", func(t *testing.T) {
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+		}
+
+		handle := pool.NewHandle()
+		assert.NotNil(t, handle)
+		assert.Equal(t, 0, handle.connectionOffset)
+		assert.Equal(t, 1, pool.handleOffset)
+	})
+
+	t.Run("next handle high offset", func(t *testing.T) {
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 13,
+			lock:         sync.RWMutex{},
+		}
+
+		handle := pool.NewHandle()
+		assert.NotNil(t, handle)
+		assert.Equal(t, 3, handle.connectionOffset)
+		assert.Equal(t, 14, pool.handleOffset)
+	})
+}
+
+func Test_AmqpConnectionPool_internalAddConnection(t *testing.T) {
+
+	t.Run("internal add connection", func(t *testing.T) {
+		conn := &amqpConnMock{}
+
+		dialer := &amqpDialMock{}
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, nil)
+
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.internalAddConnection()
+		assert.NoError(t, err)
+
+		assert.Equal(t, 1, len(pool.connections))
+		connectionProvider.AssertNumberOfCalls(t, "NewAmqpConnection", 1)
+		dialer.AssertNumberOfCalls(t, "Dial", 1)
+	})
+
+	t.Run("dialer error", func(t *testing.T) {
+		conn := &amqpConnMock{}
+
+		dialer := &amqpDialMock{}
+		var c *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(c, errors.New("test error")).Once()
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, nil)
+
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.internalAddConnection()
+		assert.NoError(t, err)
+
+		assert.Equal(t, 1, len(pool.connections))
+		connectionProvider.AssertNumberOfCalls(t, "NewAmqpConnection", 1)
+		dialer.AssertNumberOfCalls(t, "Dial", 2)
+	})
+
+	t.Run("repetitive dialer error", func(t *testing.T) {
+		dialer := &amqpDialMock{}
+		var c *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(c, errors.New("test error"))
+
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.internalAddConnection()
+		assert.EqualError(t, err, "new connection: failed to connect to amqp broker: internal connection connect: dial: test error")
+
+		assert.Equal(t, 0, len(pool.connections))
+		connectionProvider.AssertNumberOfCalls(t, "NewAmqpConnection", 1)
+		dialer.AssertNumberOfCalls(t, "Dial", 2)
+	})
+}
+
+func Test_AmqpConnectionPool_initializeConnections(t *testing.T) {
+
+	t.Run("initialize connections successfully", func(t *testing.T) {
+
+		conn := &amqpConnMock{}
+		dialer := &amqpDialMock{}
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, nil)
+
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.initializeConnections()
+		assert.NoError(t, err)
+
+		assert.Equal(t, 5, len(pool.connections))
+		connectionProvider.AssertNumberOfCalls(t, "NewAmqpConnection", 5)
+	})
+
+	t.Run("fail initialization of connections", func(t *testing.T) {
+
+		var c *amqpConnMock = nil
+		failingDialer := &amqpDialMock{}
+		failingDialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(c, errors.New("test error"))
+
+		failingConnection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         failingDialer,
+		}
+
+		conn := &amqpConnMock{}
+		successfulDialer := &amqpDialMock{}
+		successfulDialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, nil)
+
+		successfulConnection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         successfulDialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(successfulConnection).Times(4)
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(failingConnection)
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.initializeConnections()
+		assert.EqualError(t, err, "new connection: failed to connect to amqp broker: internal connection connect: dial: test error")
+
+		assert.Equal(t, 4, len(pool.connections))
+		connectionProvider.AssertNumberOfCalls(t, "NewAmqpConnection", 5)
+	})
+}
+
+func Test_AmqpConnectionPool_Close(t *testing.T) {
+
+	t.Run("close connection successfully", func(t *testing.T) {
+		// add 5 connections to the pool
+		conn := &amqpConnMock{}
+		conn.On("Close").Return(nil)
+
+		dialer := &amqpDialMock{}
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, nil)
+
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.initializeConnections()
+		assert.NoError(t, err)
+
+		assert.Equal(t, 5, len(pool.connections))
+
+		// close the pool
+		err = pool.Close()
+		assert.NoError(t, err)
+		assert.Equal(t, 0, len(pool.connections))
+	})
+
+	t.Run("close connection fail", func(t *testing.T) {
+		// add 5 connections to the pool
+		failingConn := &amqpConnMock{}
+		failingConn.On("Close").Return(errors.New("test error"))
+
+		failingDialer := &amqpDialMock{}
+		failingDialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(failingConn, nil)
+
+		failingConnection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         failingDialer,
+		}
+
+		successfulConn := &amqpConnMock{}
+		successfulConn.On("Close").Return(nil)
+		successfulDialer := &amqpDialMock{}
+		successfulDialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(successfulConn, nil)
+
+		successfulConnection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         successfulDialer,
+		}
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(successfulConnection).Times(2)
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(failingConnection).Times(2)
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(successfulConnection).Times(1)
+
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connectionProvider: connectionProvider,
+		}
+
+		err := pool.initializeConnections()
+		assert.NoError(t, err)
+
+		assert.Equal(t, 5, len(pool.connections))
+
+		// close the pool
+		err = pool.Close()
+		assert.EqualError(t, err, "connection: close: close: internal connection close: test error\nconnection: close: close: internal connection close: test error")
+		assert.Equal(t, 0, len(pool.connections))
+	})
+}
+
+func Test_AmqpConnectionPool_nextConnectionForHandle(t *testing.T) {
+	channelReceiver := func(channel chan struct{}) <-chan struct{} {
+		return channel
+	}
+
+	newActiveConnection := func() *AmqpConnection {
+		channel := make(chan struct{})
+		conn := &amqpConnMock{}
+		conn.On("Done", mock.Anything).Return(channelReceiver(channel))
+		return &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			conn:           conn,
+		}
+	}
+
+	newClosedConnection := func() *AmqpConnection {
+		channel := make(chan struct{})
+		close(channel)
+
+		conn := &amqpConnMock{}
+		conn.On("Done", mock.Anything).Return(channelReceiver(channel))
+		return &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			conn:           conn,
+		}
+	}
+
+	t.Run("next connection for requested handle", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		for i := 0; i < 5; i++ {
+			connections = append(connections, newActiveConnection())
+		}
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, addConnection := pool.nextConnectionForHandle(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.NotNil(t, connection)
+		assert.False(t, addConnection)
+	})
+
+	t.Run("nil connection for requested handle", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, newActiveConnection())
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, addConnection := pool.nextConnectionForHandle(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.NotNil(t, connection)
+		assert.True(t, addConnection)
+	})
+
+	t.Run("closed connection for requested handle", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, newClosedConnection())
+		connections = append(connections, newClosedConnection())
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, newActiveConnection())
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, addConnection := pool.nextConnectionForHandle(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.NotNil(t, connection)
+		assert.True(t, addConnection)
+	})
+
+	t.Run("no connection for requested handle", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, addConnection := pool.nextConnectionForHandle(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.Nil(t, connection)
+		assert.True(t, addConnection)
+	})
+
+	t.Run("connection for requested handle with large index", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, nil)
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, addConnection := pool.nextConnectionForHandle(&ConnectionPoolHandle{connectionOffset: 23})
+		assert.NotNil(t, connection)
+		assert.False(t, addConnection)
+	})
+
+	t.Run("connection for requested handle nil with large index", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, newActiveConnection())
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, addConnection := pool.nextConnectionForHandle(&ConnectionPoolHandle{connectionOffset: 23})
+		assert.NotNil(t, connection)
+		assert.True(t, addConnection)
+	})
+}
+
+func Test_AmqpConnectionPool_GetConnection(t *testing.T) {
+	channelReceiver := func(channel chan struct{}) <-chan struct{} {
+		return channel
+	}
+
+	newActiveConnection := func() *AmqpConnection {
+		channel := make(chan struct{})
+		conn := &amqpConnMock{}
+		conn.On("Done", mock.Anything).Return(channelReceiver(channel))
+		return &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			conn:           conn,
+		}
+	}
+
+	t.Run("get connection for requested handle", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		for i := 0; i < 5; i++ {
+			connections = append(connections, newActiveConnection())
+		}
+
+		pool := AmqpConnectionPool{
+			config:       AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset: 0,
+			lock:         sync.RWMutex{},
+			connections:  connections,
+		}
+
+		connection, err := pool.GetConnection(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.NoError(t, err)
+		assert.NotNil(t, connection)
+		assert.Equal(t, connections[1], connection)
+		assert.Equal(t, 5, len(connections))
+	})
+
+	t.Run("add connection if missing", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 5)
+
+		connectionProvider := &connectionProviderMock{}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(newActiveConnection())
+
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connections:        connections,
+			connectionProvider: connectionProvider,
+		}
+
+		connection, err := pool.GetConnection(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.NoError(t, err)
+		assert.NotNil(t, connection)
+		assert.Equal(t, connections[1], connection)
+		assert.Equal(t, 5, len(connections))
+	})
+
+	t.Run("add connection fails returns alternative connection", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, nil)
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, newActiveConnection())
+		connections = append(connections, newActiveConnection())
+
+		connectionProvider := &connectionProviderMock{}
+
+		dialer := &amqpDialMock{}
+		var c *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(c, fmt.Errorf("dial error"))
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connections:        connections,
+			connectionProvider: connectionProvider,
+		}
+
+		connection, err := pool.GetConnection(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.NoError(t, err)
+		assert.NotNil(t, connection)
+		assert.Nil(t, connections[1])
+		assert.Equal(t, connections[2], connection)
+		assert.Equal(t, 5, len(connections))
+	})
+
+	t.Run("add connection fails", func(t *testing.T) {
+		connections := make([]*AmqpConnection, 0)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+		connections = append(connections, nil)
+
+		connectionProvider := &connectionProviderMock{}
+
+		dialer := &amqpDialMock{}
+		var c *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(c, fmt.Errorf("dial error"))
+		connection := &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			dialer:         dialer,
+		}
+		connectionProvider.On("NewAmqpConnection", mock.Anything, mock.Anything).Return(connection)
+
+		pool := AmqpConnectionPool{
+			config:             AmqpConnectionPoolConfig{PoolSize: 5},
+			handleOffset:       0,
+			lock:               sync.RWMutex{},
+			connections:        connections,
+			connectionProvider: connectionProvider,
+		}
+
+		connection, err := pool.GetConnection(&ConnectionPoolHandle{connectionOffset: 1})
+		assert.EqualError(t, err, "renew connection: failed to connect to amqp broker: internal connection connect: dial: dial error")
+		assert.Nil(t, connection)
+		assert.Equal(t, 5, len(connections))
+	})
+}

audit/messaging/amqp_connection_test.go

@@ -0,0 +1,415 @@
+package messaging
+
+import (
+	"context"
+	"errors"
+	"github.com/Azure/go-amqp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"sync"
+	"testing"
+)
+
+type amqpConnMock struct {
+	mock.Mock
+}
+
+func (m *amqpConnMock) Done() <-chan struct{} {
+	args := m.Called()
+	return args.Get(0).(<-chan struct{})
+}
+
+func (m *amqpConnMock) NewSession(ctx context.Context, opts *amqp.SessionOptions) (amqpSession, error) {
+	args := m.Called(ctx, opts)
+	return args.Get(0).(amqpSession), args.Error(1)
+}
+
+func (m *amqpConnMock) Close() error {
+	args := m.Called()
+	return args.Error(0)
+}
+
+var _ amqpConn = (*amqpConnMock)(nil)
+
+type amqpDialMock struct {
+	mock.Mock
+}
+
+func (m *amqpDialMock) Dial(ctx context.Context, addr string, opts *amqp.ConnOptions) (amqpConn, error) {
+	args := m.Called(ctx, addr, opts)
+	return args.Get(0).(amqpConn), args.Error(1)
+}
+
+var _ amqpDial = (*amqpDialMock)(nil)
+
+type amqpSessionMock struct {
+	mock.Mock
+}
+
+func (m *amqpSessionMock) NewSender(ctx context.Context, target string, opts *amqp.SenderOptions) (amqpSender, error) {
+	args := m.Called(ctx, target, opts)
+	return args.Get(0).(amqpSender), args.Error(1)
+}
+
+func (m *amqpSessionMock) Close(ctx context.Context) error {
+	args := m.Called(ctx)
+	return args.Error(0)
+}
+
+var _ amqpSession = (*amqpSessionMock)(nil)
+
+func Test_AmqpConnection_IsClosed(t *testing.T) {
+	connection := &AmqpConnection{
+		connectionName: "test",
+		lock:           sync.RWMutex{},
+	}
+
+	channelReceiver := func(channel chan struct{}) <-chan struct{} {
+		return channel
+	}
+
+	t.Run("is closed - connection nil", func(t *testing.T) {
+		assert.True(t, connection.IsClosed())
+	})
+
+	t.Run("is closed", func(t *testing.T) {
+		channel := make(chan struct{})
+		close(channel)
+		amqpConnMock := &amqpConnMock{}
+		amqpConnMock.On("Done").Return(channelReceiver(channel))
+		connection.conn = amqpConnMock
+
+		assert.True(t, connection.IsClosed())
+	})
+
+	t.Run("is not closed", func(t *testing.T) {
+		channel := make(chan struct{})
+		amqpConnMock := &amqpConnMock{}
+		amqpConnMock.On("Done").Return(channelReceiver(channel))
+		connection.conn = amqpConnMock
+
+		assert.False(t, connection.IsClosed())
+	})
+}
+
+func Test_AmqpConnection_Close(t *testing.T) {
+	connection := &AmqpConnection{
+		connectionName: "test",
+		lock:           sync.RWMutex{},
+	}
+
+	t.Run("already closed", func(t *testing.T) {
+		assert.NoError(t, connection.Close())
+	})
+
+	t.Run("close error", func(t *testing.T) {
+		err := errors.New("test error")
+
+		amqpConnMock := &amqpConnMock{}
+		amqpConnMock.On("Close").Return(err)
+		connection.conn = amqpConnMock
+
+		assert.EqualError(t, connection.Close(), "close: internal connection close: test error")
+		assert.NotNil(t, connection.conn)
+		amqpConnMock.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close without error", func(t *testing.T) {
+		amqpConnMock := &amqpConnMock{}
+		amqpConnMock.On("Close").Return(nil)
+		connection.conn = amqpConnMock
+
+		assert.Nil(t, connection.Close())
+		assert.Nil(t, connection.conn)
+		amqpConnMock.AssertNumberOfCalls(t, "Close", 1)
+	})
+}
+
+func Test_AmqpConnection_Connect(t *testing.T) {
+	connection := &AmqpConnection{
+		connectionName: "test",
+		lock:           sync.RWMutex{},
+	}
+
+	t.Run("already connected", func(t *testing.T) {
+		connection.conn = &amqpConnMock{}
+		assert.NoError(t, connection.Connect())
+	})
+
+	t.Run("dial error", func(t *testing.T) {
+		connection.conn = nil
+		connection.username = "user"
+		connection.password = "pass"
+
+		amqpDialMock := &amqpDialMock{}
+		var c *amqpConnMock = nil
+		amqpDialMock.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(c, errors.New("test error"))
+		connection.dialer = amqpDialMock
+
+		assert.EqualError(t, connection.Connect(), "internal connection connect: dial: test error")
+		assert.Nil(t, connection.conn)
+	})
+
+	t.Run("connect without error", func(t *testing.T) {
+		connection.conn = nil
+
+		amqpDialMock := &amqpDialMock{}
+		amqpConn := &amqpConnMock{}
+		amqpDialMock.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(amqpConn, nil)
+		connection.dialer = amqpDialMock
+
+		assert.NoError(t, connection.Connect())
+		assert.Equal(t, amqpConn, connection.conn)
+	})
+}
+
+func Test_AmqpConnection_ResetConnection(t *testing.T) {
+	connection := &AmqpConnection{
+		connectionName: "test",
+		lock:           sync.RWMutex{},
+	}
+
+	t.Run("reset connection - connect on first attempt", func(t *testing.T) {
+		connection.conn = nil
+
+		dialer := &amqpDialMock{}
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(&amqpConnMock{}, nil)
+		connection.dialer = dialer
+
+		assert.NoError(t, connection.ResetConnection(context.Background()))
+		assert.NotNil(t, connection.conn)
+
+		dialer.AssertNumberOfCalls(t, "Dial", 1)
+	})
+
+	t.Run("reset connection - connect on second attempt", func(t *testing.T) {
+		connection.conn = nil
+
+		dialer := &amqpDialMock{}
+		var conn *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, errors.New("test error")).Once()
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(&amqpConnMock{}, nil)
+		connection.dialer = dialer
+
+		assert.NoError(t, connection.ResetConnection(context.Background()))
+		assert.NotNil(t, connection.conn)
+
+		dialer.AssertNumberOfCalls(t, "Dial", 2)
+	})
+
+	t.Run("reset connection - fail continuously", func(t *testing.T) {
+		connection.conn = nil
+
+		dialer := &amqpDialMock{}
+		var conn *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, errors.New("test error"))
+		connection.dialer = dialer
+
+		assert.EqualError(t, connection.ResetConnection(context.Background()), "connect: dial: test error")
+		assert.Nil(t, connection.conn)
+
+		dialer.AssertNumberOfCalls(t, "Dial", 2)
+	})
+}
+
+type ResettableFunction struct {
+	mock.Mock
+}
+
+func (f *ResettableFunction) Run(ctx context.Context) (any, error) {
+	args := f.Called(ctx)
+	return args.Get(0), args.Error(1)
+}
+
+func Test_AmqpConnection_ResetConnectionAndRetryIfErrorWithReturnValue(t *testing.T) {
+	connection := &AmqpConnection{
+		connectionName: "test",
+		lock:           sync.RWMutex{},
+	}
+
+	t.Run("no error", func(t *testing.T) {
+		value, err := connection.ResetConnectionAndRetryIfErrorWithReturnValue("test", func(ctx context.Context) (any, error) {
+			return struct{}{}, nil
+		})
+		assert.NoError(t, err)
+		assert.Equal(t, struct{}{}, value)
+	})
+
+	t.Run("reset - success", func(t *testing.T) {
+		connection.conn = nil
+
+		dialer := &amqpDialMock{}
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(&amqpConnMock{}, nil)
+		connection.dialer = dialer
+
+		resettableFunction := &ResettableFunction{}
+		resettableFunction.On("Run", mock.Anything).Return(struct{}{}, errors.New("test error")).Once()
+		resettableFunction.On("Run", mock.Anything).Return(struct{}{}, nil)
+
+		value, err := connection.ResetConnectionAndRetryIfErrorWithReturnValue("test", resettableFunction.Run)
+		assert.NoError(t, err)
+		assert.Equal(t, struct{}{}, value)
+
+		resettableFunction.AssertNumberOfCalls(t, "Run", 2)
+	})
+
+	t.Run("reset - fail", func(t *testing.T) {
+		connection.conn = nil
+
+		dialer := &amqpDialMock{}
+		var conn *amqpConnMock = nil
+		dialer.On("Dial", mock.Anything, mock.Anything, mock.Anything).Return(conn, errors.New("test error"))
+		connection.dialer = dialer
+
+		resettableFunction := &ResettableFunction{}
+		resettableFunction.On("Run", mock.Anything).Return(struct{}{}, errors.New("test error"))
+
+		value, err := connection.ResetConnectionAndRetryIfErrorWithReturnValue("test", resettableFunction.Run)
+		assert.EqualError(t, err, "reset connection: connect: dial: test error")
+		assert.Nil(t, value)
+
+		resettableFunction.AssertNumberOfCalls(t, "Run", 1)
+	})
+}
+
+func Test_AmqpConnection_NewSender(t *testing.T) {
+	connection := &AmqpConnection{
+		connectionName: "test",
+		lock:           sync.RWMutex{},
+	}
+
+	channelReceiver := func(channel chan struct{}) <-chan struct{} {
+		return channel
+	}
+
+	t.Run("connection not initialized", func(t *testing.T) {
+		sender, err := connection.NewSender(context.Background(), "topic")
+		assert.EqualError(t, err, "connection is not initialized")
+		assert.Nil(t, sender)
+	})
+
+	t.Run("connection is closed", func(t *testing.T) {
+		channel := make(chan struct{})
+		close(channel)
+
+		conn := &amqpConnMock{}
+		conn.On("Done").Return(channelReceiver(channel))
+		connection.conn = conn
+
+		sender, err := connection.NewSender(context.Background(), "topic")
+		assert.EqualError(t, err, "amqp connection is closed")
+		assert.Nil(t, sender)
+	})
+
+	t.Run("session error", func(t *testing.T) {
+		channel := make(chan struct{})
+
+		var session *amqpSessionMock = nil
+		conn := &amqpConnMock{}
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(session, errors.New("test error"))
+		conn.On("Done").Return(channelReceiver(channel))
+		connection.conn = conn
+
+		sender, err := connection.NewSender(context.Background(), "topic")
+		assert.EqualError(t, err, "new session: test error")
+		assert.Nil(t, sender)
+	})
+
+	t.Run("sender error", func(t *testing.T) {
+		channel := make(chan struct{})
+
+		sessionMock := &amqpSessionMock{}
+		var amqpSender *amqp.Sender = nil
+		sessionMock.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(amqpSender, errors.New("test error"))
+		sessionMock.On("Close", mock.Anything).Return(nil)
+
+		conn := &amqpConnMock{}
+		conn.On("Done").Return(channelReceiver(channel))
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(sessionMock, nil)
+		connection.conn = conn
+
+		sender, err := connection.NewSender(context.Background(), "topic")
+		assert.EqualError(t, err, "new internal sender: test error")
+		assert.Nil(t, sender)
+	})
+
+	t.Run("session close error", func(t *testing.T) {
+		channel := make(chan struct{})
+
+		sessionMock := &amqpSessionMock{}
+		var amqpSender *amqp.Sender = nil
+		sessionMock.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(amqpSender, errors.New("test error"))
+		sessionMock.On("Close", mock.Anything).Return(errors.New("close error"))
+
+		conn := &amqpConnMock{}
+		conn.On("Done").Return(channelReceiver(channel))
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(sessionMock, nil)
+		connection.conn = conn
+
+		sender, err := connection.NewSender(context.Background(), "topic")
+		assert.EqualError(t, err, "new internal sender: test error\nclose session: close error")
+		assert.Nil(t, sender)
+	})
+
+	t.Run("get sender", func(t *testing.T) {
+		channel := make(chan struct{})
+
+		amqpSender := &amqp.Sender{}
+		sessionMock := &amqpSessionMock{}
+		sessionMock.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(amqpSender, nil)
+
+		conn := &amqpConnMock{}
+		conn.On("Done").Return(channelReceiver(channel))
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(sessionMock, nil)
+		connection.conn = conn
+
+		sender, err := connection.NewSender(context.Background(), "topic")
+		assert.NoError(t, err)
+		assert.NotNil(t, sender)
+		assert.Equal(t, amqpSender, sender.sender)
+		assert.Equal(t, sessionMock, sender.session)
+	})
+}
+
+func Test_AmqpConnection_NewAmqpConnection(t *testing.T) {
+	config := AmqpConnectionConfig{
+		BrokerUrl: "brokerUrl",
+		Username:  "username",
+		Password:  "password",
+	}
+	connection := NewAmqpConnection(&config, "connectionName")
+	assert.NotNil(t, connection)
+	assert.Equal(t, connection.connectionName, "connectionName")
+	assert.Equal(t, connection.brokerUrl, "brokerUrl")
+	assert.Equal(t, connection.username, "username")
+	assert.Equal(t, connection.password, "password")
+	assert.NotNil(t, connection.dialer)
+}
+
+func Test_As(t *testing.T) {
+
+	t.Run("error", func(t *testing.T) {
+		value, err := As[amqp.Message](nil, errors.New("test error"))
+		assert.EqualError(t, err, "test error")
+		assert.Nil(t, value)
+	})
+
+	t.Run("value nil", func(t *testing.T) {
+		value, err := As[amqp.Message](nil, nil)
+		assert.NoError(t, err)
+		assert.Nil(t, value)
+	})
+
+	t.Run("value not not type", func(t *testing.T) {
+		value, err := As[amqp.Message](struct{}{}, nil)
+		assert.EqualError(t, err, "could not cast value: struct {}")
+		assert.Nil(t, value)
+	})
+
+	t.Run("cast", func(t *testing.T) {
+		var sessionAny any = &amqpSessionMock{}
+		value, err := As[amqpSessionMock](sessionAny, nil)
+		assert.NoError(t, err)
+		assert.NotNil(t, value)
+	})
+}

audit/messaging/amqp_sender_session.go

@@ -0,0 +1,86 @@
+package messaging
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/Azure/go-amqp"
+	"log/slog"
+	"strings"
+	"time"
+)
+
+type amqpSender interface {
+	Send(ctx context.Context, msg *amqp.Message, opts *amqp.SendOptions) error
+	Close(ctx context.Context) error
+}
+
+type AmqpSenderSession struct {
+	session amqpSession
+	sender  amqpSender
+}
+
+func (s *AmqpSenderSession) Send(
+	topic string,
+	data [][]byte,
+	contentType string,
+	applicationProperties map[string]any,
+) error {
+	// check topic name
+	if !strings.HasPrefix(topic, AmqpTopicPrefix) {
+		return fmt.Errorf(
+			"topic %q name lacks mandatory prefix %q",
+			topic,
+			AmqpTopicPrefix,
+		)
+	}
+
+	if contentType == "" {
+		return errors.New("content-type is required")
+	}
+
+	// prepare the amqp message
+	message := amqp.Message{
+		Header: &amqp.MessageHeader{
+			Durable: true,
+		},
+		Properties: &amqp.MessageProperties{
+			To:          &topic,
+			ContentType: &contentType,
+		},
+		ApplicationProperties: applicationProperties,
+		Data:                  data,
+	}
+
+	// send
+	ctx, cancelFn := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancelFn()
+	return s.sender.Send(ctx, &message, nil)
+}
+
+func (s *AmqpSenderSession) Close() error {
+	ctx, cancelFn := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancelFn()
+
+	var closeErrors []error
+	senderErr := s.sender.Close(ctx)
+	if senderErr != nil {
+		closeErrors = append(closeErrors, senderErr)
+	}
+	sessionErr := s.session.Close(ctx)
+	if sessionErr != nil {
+		closeErrors = append(closeErrors, sessionErr)
+	}
+
+	if len(closeErrors) > 0 {
+		return errors.Join(closeErrors...)
+	}
+	return nil
+}
+
+func (s *AmqpSenderSession) CloseSilently() {
+	err := s.Close()
+	if err != nil {
+		slog.Error("error closing sender session", slog.Any("err", err))
+	}
+}

audit/messaging/amqp_sender_session_test.go

@@ -0,0 +1,186 @@
+package messaging
+
+import (
+	"context"
+	"errors"
+	"github.com/Azure/go-amqp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"testing"
+)
+
+type amqpSenderMock struct {
+	mock.Mock
+}
+
+func (m *amqpSenderMock) Send(ctx context.Context, msg *amqp.Message, opts *amqp.SendOptions) error {
+	return m.Called(ctx, msg, opts).Error(0)
+}
+
+func (m *amqpSenderMock) Close(ctx context.Context) error {
+	return m.Called(ctx).Error(0)
+}
+
+var _ amqpSender = (*amqpSenderMock)(nil)
+
+func Test_AmqpSenderSession_Close(t *testing.T) {
+
+	t.Run("close without errors", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(nil)
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(nil)
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		err := senderSession.Close()
+		assert.NoError(t, err)
+
+		sender.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close with sender error", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(errors.New("sender error"))
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(nil)
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		err := senderSession.Close()
+		assert.EqualError(t, err, "sender error")
+
+		sender.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close with session error", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(nil)
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(errors.New("session error"))
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		err := senderSession.Close()
+		assert.EqualError(t, err, "session error")
+
+		sender.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close with sender and session error", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(errors.New("sender error"))
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(errors.New("session error"))
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		err := senderSession.Close()
+		assert.EqualError(t, err, "sender error\nsession error")
+
+		sender.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+	})
+}
+
+func Test_AmqpSenderSession_Send(t *testing.T) {
+
+	t.Run("invalid topic name", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		session := &amqpSessionMock{}
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		data := [][]byte{[]byte("data")}
+		err := senderSession.Send("invalid", data, "application/json", map[string]interface{}{})
+		assert.EqualError(t, err, "topic \"invalid\" name lacks mandatory prefix \"topic://\"")
+	})
+
+	t.Run("content type missing", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		session := &amqpSessionMock{}
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		data := [][]byte{[]byte("data")}
+		err := senderSession.Send("topic://some/name", data, "", map[string]interface{}{})
+		assert.EqualError(t, err, "content-type is required")
+	})
+
+	t.Run("send", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(nil)
+		session := &amqpSessionMock{}
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		data := [][]byte{[]byte("data")}
+		applicationProperties := map[string]interface{}{}
+		applicationProperties["key"] = "value"
+		err := senderSession.Send("topic://some/name", data, "application/json", applicationProperties)
+		assert.NoError(t, err)
+
+		sender.AssertNumberOfCalls(t, "Send", 1)
+		calls := sender.Calls
+		assert.Equal(t, 1, len(calls))
+
+		ctx, isCtx := calls[0].Arguments[0].(context.Context)
+		assert.True(t, isCtx)
+		assert.NotNil(t, ctx)
+
+		message, isMsg := calls[0].Arguments[1].(*amqp.Message)
+		assert.True(t, isMsg)
+		assert.True(t, message.Header.Durable)
+		assert.Equal(t, "topic://some/name", *message.Properties.To)
+		assert.Equal(t, "application/json", *message.Properties.ContentType)
+		assert.Equal(t, applicationProperties, message.ApplicationProperties)
+		assert.Equal(t, data, message.Data)
+
+		senderOptions, isSenderOptions := calls[0].Arguments[2].(*amqp.SendOptions)
+		assert.True(t, isSenderOptions)
+		assert.Nil(t, senderOptions)
+	})
+
+	t.Run("send fails", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(errors.New("send fail"))
+		session := &amqpSessionMock{}
+
+		senderSession := &AmqpSenderSession{
+			sender:  sender,
+			session: session,
+		}
+
+		data := [][]byte{[]byte("data")}
+		applicationProperties := map[string]interface{}{}
+		applicationProperties["key"] = "value"
+
+		err := senderSession.Send("topic://some/name", data, "application/json", applicationProperties)
+		assert.EqualError(t, err, "send fail")
+		sender.AssertNumberOfCalls(t, "Send", 1)
+	})
+}

audit/messaging/messaging.go

@@ -2,19 +2,13 @@ package messaging
 
 import (
 	"context"
+	"dev.azure.com/schwarzit/schwarzit.stackit-public/audit-go.git/log"
 	"errors"
 	"fmt"
-	"strings"
 	"sync"
 	"time"
-
-	"dev.azure.com/schwarzit/schwarzit.stackit-public/audit-go.git/log"
-	"github.com/Azure/go-amqp"
 )
 
-// Default connection timeout for the AMQP connection
-const connectionTimeoutSeconds = 10
-
 // Api is an abstraction for a messaging system that can be used to send
 // audit logs to the audit log system.
 type Api interface {
@@ -38,203 +32,99 @@ type Api interface {
 	Close(ctx context.Context) error
 }
 
-// MutexApi is wrapper around an API implementation that controls mutual exclusive access to the api.
-type MutexApi struct {
-	mutex sync.Mutex
-	api   Api
-}
-
-var _ Api = &MutexApi{}
-
-func NewMutexApi(api Api) (Api, error) {
-	if api == nil {
-		return nil, errors.New("api is nil")
-	}
-	mutexApi := MutexApi{
-		mutex: sync.Mutex{},
-		api:   api,
-	}
-
-	var genericApi Api = &mutexApi
-	return genericApi, nil
-}
-
-// Send implements Api.Send
-func (m *MutexApi) Send(ctx context.Context, topic string, data []byte, contentType string, applicationProperties map[string]any) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-	return m.api.Send(ctx, topic, data, contentType, applicationProperties)
-}
-
-func (m *MutexApi) Close(ctx context.Context) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-	return m.api.Close(ctx)
-}
-
-// AmqpConfig provides AMQP connection related parameters.
-type AmqpConfig struct {
-	URL      string
-	User     string
-	Password string
-}
-
-// AmqpSession is an abstraction providing a subset of the methods of amqp.Session
-type AmqpSession interface {
-	NewSender(ctx context.Context, target string, opts *amqp.SenderOptions) (AmqpSender, error)
-	Close(ctx context.Context) error
-}
-
-type AmqpSessionWrapper struct {
-	session *amqp.Session
-}
-
-func (w AmqpSessionWrapper) NewSender(ctx context.Context, target string, opts *amqp.SenderOptions) (AmqpSender, error) {
-	return w.session.NewSender(ctx, target, opts)
-}
-
-func (w AmqpSessionWrapper) Close(ctx context.Context) error {
-	return w.session.Close(ctx)
-}
-
-// AmqpSender is an abstraction providing a subset of the methods of amqp.Sender
-type AmqpSender interface {
-	Send(ctx context.Context, msg *amqp.Message, opts *amqp.SendOptions) error
-	Close(ctx context.Context) error
-}
-
 // AmqpApi implements Api.
 type AmqpApi struct {
-	config     AmqpConfig
-	connection *amqp.Conn
-	session    AmqpSession
+	config               AmqpConnectionPoolConfig
+	connection           *AmqpConnection
+	connectionPool       ConnectionPool
+	connectionPoolHandle *ConnectionPoolHandle
+	senderCache          map[string]*AmqpSenderSession
+	lock                 sync.RWMutex
 }
 
 var _ Api = &AmqpApi{}
 
-func NewAmqpApi(amqpConfig AmqpConfig) (Api, error) {
-	amqpApi := &AmqpApi{config: amqpConfig}
-
-	if err := amqpApi.connect(); err != nil {
-		return nil, fmt.Errorf("connect to broker: %w", err)
-	}
-
-	return amqpApi, nil
-}
-
-// connect opens a new connection and session to the AMQP messaging system.
-// The connection attempt will be cancelled after connectionTimeoutSeconds.
-func (a *AmqpApi) connect() error {
-	log.AuditLogger.Info("connecting to audit messaging system")
-
-	// Set credentials if specified
-	auth := amqp.SASLTypeAnonymous()
-
-	if a.config.User != "" && a.config.Password != "" {
-		auth = amqp.SASLTypePlain(a.config.User, a.config.Password)
-		log.AuditLogger.Info("using username and password for messaging")
-	} else {
-		log.AuditLogger.Warn("using anonymous messaging!")
-	}
-
-	options := &amqp.ConnOptions{
-		SASLType: auth,
-	}
-
-	// Create new context with timeout for the connection initialization
-	subCtx, cancel := context.WithTimeout(context.Background(), connectionTimeoutSeconds*time.Second)
-	defer cancel()
-
-	// Initialize connection
-	conn, err := amqp.Dial(subCtx, a.config.URL, options)
+func NewAmqpApi(amqpConfig AmqpConnectionPoolConfig) (Api, error) {
+	connectionPool, err := NewAmqpConnectionPool(amqpConfig, "sdk")
 	if err != nil {
-		return fmt.Errorf("dial connection to broker: %w", err)
-	}
-	a.connection = conn
-
-	// Initialize session
-	session, err := conn.NewSession(context.Background(), nil)
-	if err != nil {
-		return fmt.Errorf("create session: %w", err)
+		return nil, fmt.Errorf("new amqp connection pool: %w", err)
 	}
 
-	var amqpSession AmqpSession = &AmqpSessionWrapper{session: session}
-	a.session = amqpSession
+	amqpApi := &AmqpApi{config: amqpConfig,
+		connectionPool:       connectionPool,
+		connectionPoolHandle: connectionPool.NewHandle(),
+		senderCache:          make(map[string]*AmqpSenderSession),
+	}
 
-	return nil
+	var messagingApi Api = amqpApi
+	return messagingApi, nil
 }
 
 // Send implements Api.Send.
 // If errors occur the connection to the messaging system will be closed and re-established.
 func (a *AmqpApi) Send(ctx context.Context, topic string, data []byte, contentType string, applicationProperties map[string]any) error {
-	err := a.trySend(ctx, topic, data, contentType, applicationProperties)
-	if err == nil {
-		return nil
-	}
 
-	// Drop the current sender, as it cannot connect to the broker anymore
-	log.AuditLogger.Error("message sender error, recreating", err)
-
-	err = a.resetConnection(ctx)
-	if err != nil {
-		return fmt.Errorf("reset connection: %w", err)
-	}
-
-	return a.trySend(ctx, topic, data, contentType, applicationProperties)
-}
-
-// trySend actually sends the given data as amqp.Message to the messaging system.
-func (a *AmqpApi) trySend(ctx context.Context, topic string, data []byte, contentType string, applicationProperties map[string]any) error {
-	if !strings.HasPrefix(topic, AmqpTopicPrefix) {
-		return fmt.Errorf(
-			"topic %q name lacks mandatory prefix %q",
-			topic,
-			AmqpTopicPrefix,
-		)
-	}
-
-	sender, err := a.session.NewSender(ctx, topic, nil)
-	if err != nil {
-		return fmt.Errorf("new sender: %w", err)
-	}
-	defer func() {
-		if err := sender.Close(ctx); err != nil {
-			log.AuditLogger.Error("failed to close session sender", err)
+	a.lock.RLock()
+	connectionIsClosed := a.connection == nil || a.connection.IsClosed()
+	a.lock.RUnlock()
+	if connectionIsClosed {
+		connection, err := a.connectionPool.GetConnection(a.connectionPoolHandle)
+		if err != nil {
+			return fmt.Errorf("get connection: %w", err)
 		}
-	}()
-
-	bytes := [][]byte{data}
-	message := amqp.Message{
-		Header: &amqp.MessageHeader{
-			Durable: true,
-		},
-		Properties: &amqp.MessageProperties{
-			To:          &topic,
-			ContentType: &contentType,
-		},
-		ApplicationProperties: applicationProperties,
-		Data:                  bytes,
+		a.lock.Lock()
+		a.connection = connection
+		a.lock.Unlock()
 	}
 
-	err = sender.Send(ctx, &message, nil)
-	if err != nil {
-		return fmt.Errorf("send message: %w", err)
+	a.lock.RLock()
+	var sender = a.senderCache[topic]
+	a.lock.RUnlock()
+	if sender == nil {
+		a.lock.RLock()
+		ctx, cancelFn := context.WithTimeout(ctx, 10*time.Second)
+		senderSession, err := a.connection.NewSender(ctx, topic)
+		cancelFn()
+		a.lock.RUnlock()
+		if err != nil {
+			return fmt.Errorf("new sender: %w", err)
+		}
+		a.lock.Lock()
+		a.senderCache[topic] = senderSession
+		a.lock.Unlock()
+		sender = senderSession
 	}
 
+	wrappedData := [][]byte{data}
+	if err := sender.Send(topic, wrappedData, contentType, applicationProperties); err != nil {
+		return fmt.Errorf("send: %w", err)
+	}
 	return nil
 }
 
-// resetConnection closes the current session and connection and reconnects to the messaging system.
-func (a *AmqpApi) resetConnection(ctx context.Context) error {
-	if err := a.Close(ctx); err != nil {
-		log.AuditLogger.Error("failed to close audit messaging connection", err)
+// Close implements Api.Close
+func (a *AmqpApi) Close(_ context.Context) error {
+	log.AuditLogger.Info("close audit amqp connection pool")
+
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
+	// cached senders
+	var closeErrors []error
+	for _, session := range a.senderCache {
+		if err := session.Close(); err != nil {
+			closeErrors = append(closeErrors, fmt.Errorf("close session: %w", err))
+		}
+	}
+	clear(a.senderCache)
+
+	// pool
+	if err := a.connectionPool.Close(); err != nil {
+		closeErrors = append(closeErrors, fmt.Errorf("close pool: %w", err))
 	}
 
-	return a.connect()
-}
-
-// Close implements Api.Close
-func (a *AmqpApi) Close(ctx context.Context) error {
-	log.AuditLogger.Info("close audit messaging connection")
-	return errors.Join(a.session.Close(ctx), a.connection.Close())
+	if len(closeErrors) > 0 {
+		return fmt.Errorf("close: %w", errors.Join(closeErrors...))
+	}
+	return nil
 }

audit/messaging/messaging_test.go

@@ -4,50 +4,38 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"testing"
-	"time"
-
-	"github.com/Azure/go-amqp"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"sync"
+	"testing"
+	"time"
 )
 
-type AmqpSessionMock struct {
+type connectionPoolMock struct {
 	mock.Mock
 }
 
-func (m *AmqpSessionMock) NewSender(ctx context.Context, target string, opts *amqp.SenderOptions) (AmqpSender, error) {
-	args := m.Called(ctx, target, opts)
-	var sender AmqpSender = nil
-	if args.Get(0) != nil {
-		sender = args.Get(0).(AmqpSender)
-	}
-	err := args.Error(1)
-	return sender, err
+func (m *connectionPoolMock) Close() error {
+	return m.Called().Error(0)
 }
 
-func (m *AmqpSessionMock) Close(ctx context.Context) error {
-	args := m.Called(ctx)
-	return args.Error(0)
+func (m *connectionPoolMock) NewHandle() *ConnectionPoolHandle {
+	return m.Called().Get(0).(*ConnectionPoolHandle)
 }
 
-type AmqpSenderMock struct {
-	mock.Mock
+func (m *connectionPoolMock) GetConnection(handle *ConnectionPoolHandle) (*AmqpConnection, error) {
+	return m.Called(handle).Get(0).(*AmqpConnection), m.Called(handle).Error(1)
 }
 
-func (m *AmqpSenderMock) Send(ctx context.Context, msg *amqp.Message, opts *amqp.SendOptions) error {
-	args := m.Called(ctx, msg, opts)
-	return args.Error(0)
-}
-
-func (m *AmqpSenderMock) Close(ctx context.Context) error {
-	args := m.Called(ctx)
-	return args.Error(0)
-}
+var _ ConnectionPool = (*connectionPoolMock)(nil)
 
 func Test_NewAmqpMessagingApi(t *testing.T) {
-	_, err := NewAmqpApi(AmqpConfig{URL: "not-handled-protocol://localhost:5672"})
-	assert.EqualError(t, err, "connect to broker: dial connection to broker: unsupported scheme \"not-handled-protocol\"")
+	_, err := NewAmqpApi(
+		AmqpConnectionPoolConfig{
+			Parameters: AmqpConnectionConfig{BrokerUrl: "not-handled-protocol://localhost:5672"},
+			PoolSize:   1,
+		})
+	assert.EqualError(t, err, "new amqp connection pool: initialize connections: new connection: failed to connect to amqp broker: internal connection connect: dial: unsupported scheme \"not-handled-protocol\"")
 }
 
 func Test_AmqpMessagingApi_Send(t *testing.T) {
@@ -63,121 +51,354 @@ func Test_AmqpMessagingApi_Send(t *testing.T) {
 	t.Run("Missing topic prefix", func(t *testing.T) {
 		defer solaceContainer.StopOnError()
 
-		api, err := NewAmqpApi(AmqpConfig{URL: solaceContainer.AmqpConnectionString})
+		api, err := NewAmqpApi(AmqpConnectionPoolConfig{
+			Parameters: AmqpConnectionConfig{BrokerUrl: solaceContainer.AmqpConnectionString},
+			PoolSize:   1,
+		})
 		assert.NoError(t, err)
 
 		err = api.Send(ctx, "topic-name", []byte{}, "application/json", make(map[string]any))
-		assert.EqualError(t, err, "topic \"topic-name\" name lacks mandatory prefix \"topic://\"")
+		assert.EqualError(t, err, "send: topic \"topic-name\" name lacks mandatory prefix \"topic://\"")
 	})
 
-	t.Run("Close connection without errors", func(t *testing.T) {
+	t.Run("send successfully", func(t *testing.T) {
 		defer solaceContainer.StopOnError()
 
 		// Initialize the solace queue
 		topicSubscriptionTopicPattern := "auditlog/>"
-		queueName := "close-connection-without-error"
+		queueName := "send-successfully"
 		assert.NoError(t, solaceContainer.QueueCreate(ctx, queueName))
 		assert.NoError(t, solaceContainer.TopicSubscriptionCreate(ctx, queueName, topicSubscriptionTopicPattern))
-		topicName := fmt.Sprintf("topic://auditlog/%s", "amqp-close-connection")
+		topicName := fmt.Sprintf("topic://auditlog/%s", "amqp-send-successfully")
 		assert.NoError(t, solaceContainer.ValidateTopicName(topicSubscriptionTopicPattern, topicName))
 
-		api := &AmqpApi{config: AmqpConfig{URL: solaceContainer.AmqpConnectionString}}
-		err := api.connect()
+		api, err := NewAmqpApi(AmqpConnectionPoolConfig{
+			Parameters: AmqpConnectionConfig{BrokerUrl: solaceContainer.AmqpConnectionString},
+			PoolSize:   1,
+		})
 		assert.NoError(t, err)
 
+		data := []byte("data")
+		applicationProperties := make(map[string]interface{})
+		applicationProperties["key"] = "value"
+
+		err = api.Send(ctx, topicName, data, "application/json", applicationProperties)
+		assert.NoError(t, err)
+
+		message, err := solaceContainer.NextMessage(ctx, fmt.Sprintf("queue://%s", queueName), true)
+		assert.NoError(t, err)
+		assert.Equal(t, "data", string(message.Data[0]))
+		assert.Equal(t, topicName, *message.Properties.To)
+		assert.Equal(t, "application/json", *message.Properties.ContentType)
+		assert.Equal(t, applicationProperties, message.ApplicationProperties)
+
 		err = api.Close(ctx)
 		assert.NoError(t, err)
 	})
+}
 
-	t.Run("New sender call returns error", func(t *testing.T) {
-		defer solaceContainer.StopOnError()
+func Test_AmqpMessagingApi_Send_Special_Cases(t *testing.T) {
 
-		// Initialize the solace queue
-		topicSubscriptionTopicPattern := "auditlog/>"
-		queueName := "messaging-new-sender"
-		assert.NoError(t, solaceContainer.QueueCreate(ctx, queueName))
-		assert.NoError(t, solaceContainer.TopicSubscriptionCreate(ctx, queueName, topicSubscriptionTopicPattern))
-		topicName := fmt.Sprintf("topic://auditlog/%s", "amqp-no-new-sender")
-		assert.NoError(t, solaceContainer.ValidateTopicName(topicSubscriptionTopicPattern, topicName))
+	channelReceiver := func(channel chan struct{}) <-chan struct{} {
+		return channel
+	}
 
-		api := &AmqpApi{config: AmqpConfig{URL: solaceContainer.AmqpConnectionString}}
-		err := api.connect()
+	newActiveConnection := func() *AmqpConnection {
+		channel := make(chan struct{})
+		conn := &amqpConnMock{}
+		conn.On("Done", mock.Anything).Return(channelReceiver(channel))
+		return &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			conn:           conn,
+		}
+	}
+
+	newClosedConnection := func() *AmqpConnection {
+		channel := make(chan struct{})
+		close(channel)
+
+		conn := &amqpConnMock{}
+		conn.On("Done", mock.Anything).Return(channelReceiver(channel))
+		return &AmqpConnection{
+			connectionName: "test",
+			lock:           sync.RWMutex{},
+			conn:           conn,
+		}
+	}
+
+	t.Run("connection nil sender nil", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(nil)
+
+		session := &amqpSessionMock{}
+		session.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(sender, nil)
+
+		connection := newActiveConnection()
+		conn := connection.conn.(*amqpConnMock)
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(session, nil)
+
+		pool := &connectionPoolMock{}
+		pool.On("GetConnection", mock.Anything).Return(connection, nil)
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          make(map[string]*AmqpSenderSession),
+		}
+
+		err := amqpApi.Send(context.Background(), "topic://some-topic", []byte("data"), "application/json", make(map[string]any))
 		assert.NoError(t, err)
 
-		expectedError := errors.New("expected error")
-
-		// Set mock session
-		sessionMock := AmqpSessionMock{}
-		sessionMock.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(nil, expectedError)
-		sessionMock.On("Close", mock.Anything).Return(nil)
-
-		var amqpSession AmqpSession = &sessionMock
-		api.session = amqpSession
-
-		// It's expected that the test succeeds.
-		// First the session is closed as it returns the expected error
-		// Then the retry mechanism restarts the connection and successfully sends the data
-		value := "test"
-		err = api.Send(ctx, topicName, []byte(value), "application/json", make(map[string]any))
-		assert.NoError(t, err)
-
-		// Check that the mock was called
-		assert.True(t, sessionMock.AssertNumberOfCalls(t, "NewSender", 1))
-		assert.True(t, sessionMock.AssertNumberOfCalls(t, "Close", 1))
-
-		message, err := solaceContainer.NextMessage(ctx, fmt.Sprintf("queue://%s", queueName), true)
-		assert.NoError(t, err)
-		assert.Equal(t, value, string(message.Data[0]))
-		assert.Equal(t, topicName, *message.Properties.To)
+		sender.AssertNumberOfCalls(t, "Send", 1)
+		session.AssertNumberOfCalls(t, "NewSender", 1)
+		pool.AssertNumberOfCalls(t, "GetConnection", 2)
 	})
 
-	t.Run("Send call on sender returns error", func(t *testing.T) {
-		defer solaceContainer.StopOnError()
+	t.Run("connection closed sender nil", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(nil)
 
-		// Initialize the solace queue
-		topicSubscriptionTopicPattern := "auditlog/>"
-		queueName := "messaging-sender-error"
-		assert.NoError(t, solaceContainer.QueueCreate(ctx, queueName))
-		assert.NoError(t, solaceContainer.TopicSubscriptionCreate(ctx, queueName, topicSubscriptionTopicPattern))
-		topicName := fmt.Sprintf("topic://auditlog/%s", "amqp-sender-error")
-		assert.NoError(t, solaceContainer.ValidateTopicName(topicSubscriptionTopicPattern, topicName))
+		session := &amqpSessionMock{}
+		session.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(sender, nil)
 
-		api := &AmqpApi{config: AmqpConfig{URL: solaceContainer.AmqpConnectionString}}
-		err := api.connect()
+		connection := newActiveConnection()
+		conn := connection.conn.(*amqpConnMock)
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(session, nil)
+
+		pool := &connectionPoolMock{}
+		pool.On("GetConnection", mock.Anything).Return(connection, nil)
+
+		closedConnection := newClosedConnection()
+		closedConnMock := closedConnection.conn.(*amqpConnMock)
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connection:           closedConnection,
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          make(map[string]*AmqpSenderSession),
+		}
+
+		err := amqpApi.Send(context.Background(), "topic://some-topic", []byte("data"), "application/json", make(map[string]any))
 		assert.NoError(t, err)
 
-		expectedError := errors.New("expected error")
+		sender.AssertNumberOfCalls(t, "Send", 1)
+		session.AssertNumberOfCalls(t, "NewSender", 1)
+		pool.AssertNumberOfCalls(t, "GetConnection", 2)
+		closedConnMock.AssertNumberOfCalls(t, "Done", 1)
+	})
 
-		// Instantiate mock sender
-		senderMock := AmqpSenderMock{}
-		senderMock.On("Send", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Return(expectedError)
-		senderMock.On("Close", mock.Anything).Return(nil)
-		var amqpSender AmqpSender = &senderMock
+	t.Run("connection nil get connection fail", func(t *testing.T) {
+		var connection *AmqpConnection = nil
 
-		// Set mock session
-		sessionMock := AmqpSessionMock{}
-		sessionMock.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(&amqpSender, nil)
-		sessionMock.On("Close", mock.Anything).Return(nil)
+		pool := &connectionPoolMock{}
+		pool.On("GetConnection", mock.Anything).Return(connection, errors.New("connection error"))
 
-		var amqpSession AmqpSession = &sessionMock
-		api.session = amqpSession
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          make(map[string]*AmqpSenderSession),
+		}
 
-		// It's expected that the test succeeds.
-		// First the sender and session are closed as the sender returns the expected error
-		// Then the retry mechanism restarts the connection and successfully sends the data
-		value := "test"
-		err = api.Send(ctx, topicName, []byte(value), "application/json", make(map[string]any))
+		err := amqpApi.Send(context.Background(), "topic://some-topic", []byte("data"), "application/json", make(map[string]any))
+		assert.EqualError(t, err, "get connection: connection error")
+
+		pool.AssertNumberOfCalls(t, "GetConnection", 2)
+	})
+
+	t.Run("connection active sender nil", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(nil)
+
+		session := &amqpSessionMock{}
+		session.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(sender, nil)
+
+		connection := newActiveConnection()
+		conn := connection.conn.(*amqpConnMock)
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(session, nil)
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connection:  connection,
+			senderCache: make(map[string]*AmqpSenderSession),
+		}
+
+		err := amqpApi.Send(context.Background(), "topic://some-topic", []byte("data"), "application/json", make(map[string]any))
 		assert.NoError(t, err)
 
-		// Check that the mocks were called
-		assert.True(t, sessionMock.AssertNumberOfCalls(t, "NewSender", 1))
-		assert.True(t, sessionMock.AssertNumberOfCalls(t, "Close", 1))
-		assert.True(t, senderMock.AssertNumberOfCalls(t, "Send", 1))
-		assert.True(t, senderMock.AssertNumberOfCalls(t, "Close", 1))
+		sender.AssertNumberOfCalls(t, "Send", 1)
+		session.AssertNumberOfCalls(t, "NewSender", 1)
+	})
 
-		message, err := solaceContainer.NextMessage(ctx, fmt.Sprintf("queue://%s", queueName), true)
+	t.Run("connection active new sender fail", func(t *testing.T) {
+		var sender *amqpSenderMock = nil
+
+		session := &amqpSessionMock{}
+		session.On("NewSender", mock.Anything, mock.Anything, mock.Anything).Return(sender, errors.New("new sender error"))
+		session.On("Close", mock.Anything).Return(nil)
+
+		connection := newActiveConnection()
+		conn := connection.conn.(*amqpConnMock)
+		conn.On("NewSession", mock.Anything, mock.Anything).Return(session, nil)
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connection:  connection,
+			senderCache: make(map[string]*AmqpSenderSession),
+		}
+
+		err := amqpApi.Send(context.Background(), "topic://some-topic", []byte("data"), "application/json", make(map[string]any))
+		assert.EqualError(t, err, "new sender: new internal sender: new sender error")
+
+		session.AssertNumberOfCalls(t, "NewSender", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("connection active sender set", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(nil)
+
+		topic := "topic://some-topic"
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connection:  newActiveConnection(),
+			senderCache: map[string]*AmqpSenderSession{topic: {sender: sender}},
+		}
+
+		err := amqpApi.Send(context.Background(), topic, []byte("data"), "application/json", make(map[string]any))
 		assert.NoError(t, err)
-		assert.Equal(t, value, string(message.Data[0]))
-		assert.Equal(t, topicName, *message.Properties.To)
+
+		sender.AssertNumberOfCalls(t, "Send", 1)
+	})
+
+	t.Run("send fail", func(t *testing.T) {
+		sender := &amqpSenderMock{}
+		sender.On("Send", mock.Anything, mock.Anything, mock.Anything).Return(errors.New("send error"))
+
+		topic := "topic://some-topic"
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connection:  newActiveConnection(),
+			senderCache: map[string]*AmqpSenderSession{topic: {sender: sender}},
+		}
+
+		err := amqpApi.Send(context.Background(), topic, []byte("data"), "application/json", make(map[string]any))
+		assert.EqualError(t, err, "send: send error")
+
+		sender.AssertNumberOfCalls(t, "Send", 1)
+	})
+}
+
+func Test_AmqpMessagingApi_Close(t *testing.T) {
+
+	t.Run("close without cached senders", func(t *testing.T) {
+		pool := &connectionPoolMock{}
+		pool.On("Close").Return(nil)
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          make(map[string]*AmqpSenderSession),
+		}
+
+		err := amqpApi.Close(context.Background())
+		assert.NoError(t, err)
+
+		pool.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close fail without cached senders", func(t *testing.T) {
+		pool := &connectionPoolMock{}
+		pool.On("Close").Return(errors.New("close error"))
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          make(map[string]*AmqpSenderSession),
+		}
+
+		err := amqpApi.Close(context.Background())
+		assert.EqualError(t, err, "close: close pool: close error")
+
+		pool.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close with cached senders", func(t *testing.T) {
+		pool := &connectionPoolMock{}
+		pool.On("Close").Return(nil)
+
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(nil)
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(nil)
+		senderSession := &AmqpSenderSession{
+			session: session,
+			sender:  sender,
+		}
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          map[string]*AmqpSenderSession{"key": senderSession},
+		}
+
+		err := amqpApi.Close(context.Background())
+		assert.NoError(t, err)
+		assert.Equal(t, 0, len(amqpApi.senderCache))
+
+		pool.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+		sender.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close fail with cached senders", func(t *testing.T) {
+		pool := &connectionPoolMock{}
+		pool.On("Close").Return(nil)
+
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(nil)
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(errors.New("close sender error"))
+		senderSession := &AmqpSenderSession{
+			session: session,
+			sender:  sender,
+		}
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          map[string]*AmqpSenderSession{"key": senderSession},
+		}
+
+		err := amqpApi.Close(context.Background())
+		assert.EqualError(t, err, "close: close session: close sender error")
+		assert.Equal(t, 0, len(amqpApi.senderCache))
+
+		pool.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+		sender.AssertNumberOfCalls(t, "Close", 1)
+	})
+
+	t.Run("close fail", func(t *testing.T) {
+		pool := &connectionPoolMock{}
+		pool.On("Close").Return(errors.New("close pool error"))
+
+		session := &amqpSessionMock{}
+		session.On("Close", mock.Anything).Return(errors.New("close session error"))
+		sender := &amqpSenderMock{}
+		sender.On("Close", mock.Anything).Return(errors.New("close sender error"))
+		senderSession := &AmqpSenderSession{
+			session: session,
+			sender:  sender,
+		}
+
+		amqpApi := &AmqpApi{config: AmqpConnectionPoolConfig{},
+			connectionPool:       pool,
+			connectionPoolHandle: &ConnectionPoolHandle{connectionOffset: 0},
+			senderCache:          map[string]*AmqpSenderSession{"key": senderSession},
+		}
+
+		err := amqpApi.Close(context.Background())
+		assert.EqualError(t, err, "close: close session: close sender error\nclose session error\nclose pool: close pool error")
+		assert.Equal(t, 0, len(amqpApi.senderCache))
+
+		pool.AssertNumberOfCalls(t, "Close", 1)
+		session.AssertNumberOfCalls(t, "Close", 1)
+		sender.AssertNumberOfCalls(t, "Close", 1)
 	})
 }

audit/messaging/solace.go

@@ -18,7 +18,6 @@ import (
 )
 
 const (
-	AmqpTopicPrefix = "topic://"
 	AmqpQueuePrefix = "queue://"
 )