Add support for additional AMQP URI query parameters

https://www.rabbitmq.com/docs/uri-query-parameters specifies several parameters that are used in this library, but not yet supported in URIs.

This commit adds support for the following parameters:
auth_mechanism
heartbeat
connection_timeout
channel_max

Fix default value check when setting SASL authentication from URI

Add documentation for added query parameters

Add support for additional AMQP URI query parameters

https://www.rabbitmq.com/docs/uri-query-parameters specifies several parameters that are used in this library, but not yet supported in URIs.

This commit adds support for the following parameters:
auth_mechanism
heartbeat
connection_timeout
channel_max

Fix default value check when setting SASL authentication from URI

Fix ChannelMax type mismatch

connection.go

@@ -206,18 +206,46 @@ func DialConfig(url string, config Config) (*Connection, error) {
 	}
 
 	if config.SASL == nil {
-		config.SASL = []Authentication{uri.PlainAuth()}
+		if uri.AuthMechanism != nil {
+			for _, identifier := range uri.AuthMechanism {
+				switch strings.ToUpper(identifier) {
+				case "PLAIN":
+					config.SASL = append(config.SASL, uri.PlainAuth())
+				case "AMQPLAIN":
+					config.SASL = append(config.SASL, uri.AMQPlainAuth())
+				case "EXTERNAL":
+					config.SASL = append(config.SASL, &ExternalAuth{})
+				default:
+					return nil, fmt.Errorf("unsupported auth_mechanism: %v", identifier)
+				}
+			}
+		} else {
+			config.SASL = []Authentication{uri.PlainAuth()}
+		}
 	}
 
 	if config.Vhost == "" {
 		config.Vhost = uri.Vhost
 	}
 
+	if config.Heartbeat == 0 {
+		config.Heartbeat = time.Duration(uri.Heartbeat) * time.Second
+	}
+
+	if config.ChannelMax == 0 {
+		config.ChannelMax = uri.ChannelMax
+	}
+
+	connectionTimeout := defaultConnectionTimeout
+	if uri.ConnectionTimeout != 0 {
+		connectionTimeout = time.Duration(uri.ConnectionTimeout) * time.Millisecond
+	}
+
 	addr := net.JoinHostPort(uri.Host, strconv.FormatInt(int64(uri.Port), 10))
 
 	dialer := config.Dial
 	if dialer == nil {
-		dialer = DefaultDial(defaultConnectionTimeout)
+		dialer = DefaultDial(connectionTimeout)
 	}
 
 	conn, err = dialer("tcp", addr)

uri.go

@@ -7,6 +7,7 @@ package amqp091
 
 import (
 	"errors"
+	"fmt"
 	"net"
 	"net/url"
 	"strconv"
@@ -32,16 +33,20 @@ var defaultURI = URI{
 
 // URI represents a parsed AMQP URI string.
 type URI struct {
-	Scheme     string
-	Host       string
-	Port       int
-	Username   string
-	Password   string
-	Vhost      string
-	CertFile   string // client TLS auth - path to certificate (PEM)
-	CACertFile string // client TLS auth - path to CA certificate (PEM)
-	KeyFile    string // client TLS auth - path to private key (PEM)
-	ServerName string // client TLS auth - server name
+	Scheme            string
+	Host              string
+	Port              int
+	Username          string
+	Password          string
+	Vhost             string
+	CertFile          string // client TLS auth - path to certificate (PEM)
+	CACertFile        string // client TLS auth - path to CA certificate (PEM)
+	KeyFile           string // client TLS auth - path to private key (PEM)
+	ServerName        string // client TLS auth - server name
+	AuthMechanism     []string
+	Heartbeat         int
+	ConnectionTimeout int
+	ChannelMax        uint16
 }
 
 // ParseURI attempts to parse the given AMQP URI according to the spec.
@@ -62,6 +67,10 @@ type URI struct {
 //	keyfile: <path/to/client_key.pem>
 //	cacertfile: <path/to/ca.pem>
 //	server_name_indication: <server name>
+//	auth_mechanism: <one or more: plain, amqplain, external>
+//	heartbeat: <seconds (integer)>
+//	connection_timeout: <milliseconds (integer)>
+//	channel_max: <max number of channels (integer)>
 //
 // If cacertfile is not provided, system CA certificates will be used.
 // Mutual TLS (client auth) will be enabled only in case keyfile AND certfile provided.
@@ -134,6 +143,31 @@ func ParseURI(uri string) (URI, error) {
 	builder.KeyFile = params.Get("keyfile")
 	builder.CACertFile = params.Get("cacertfile")
 	builder.ServerName = params.Get("server_name_indication")
+	builder.AuthMechanism = params["auth_mechanism"]
+
+	if params.Has("heartbeat") {
+		value, err := strconv.Atoi(params.Get("heartbeat"))
+		if err != nil {
+			return builder, fmt.Errorf("heartbeat is not an integer: %v", err)
+		}
+		builder.Heartbeat = value
+	}
+
+	if params.Has("connection_timeout") {
+		value, err := strconv.Atoi(params.Get("connection_timeout"))
+		if err != nil {
+			return builder, fmt.Errorf("connection_timeout is not an integer: %v", err)
+		}
+		builder.ConnectionTimeout = value
+	}
+
+	if params.Has("channel_max") {
+		value, err := strconv.ParseUint(params.Get("channel_max"), 10, 16)
+		if err != nil {
+			return builder, fmt.Errorf("connection_timeout is not an integer: %v", err)
+		}
+		builder.ChannelMax = uint16(value)
+	}
 
 	return builder, nil
 }

uri_test.go

@@ -6,6 +6,7 @@
 package amqp091
 
 import (
+	"reflect"
 	"testing"
 )
 
@@ -388,3 +389,23 @@ func TestURITLSConfig(t *testing.T) {
 		t.Fatal("Server name not set")
 	}
 }
+
+func TestURIParameters(t *testing.T) {
+	url := "amqps://foo.bar/?auth_mechanism=plain&auth_mechanism=amqpplain&heartbeat=2&connection_timeout=5000&channel_max=8"
+	uri, err := ParseURI(url)
+	if err != nil {
+		t.Fatal("Could not parse")
+	}
+	if !reflect.DeepEqual(uri.AuthMechanism, []string{"plain", "amqpplain"}) {
+		t.Fatal("AuthMechanism not set")
+	}
+	if uri.Heartbeat != 2 {
+		t.Fatal("Heartbeat not set")
+	}
+	if uri.ConnectionTimeout != 5000 {
+		t.Fatal("ConnectionTimeout not set")
+	}
+	if uri.ChannelMax != 8 {
+		t.Fatal("ChannelMax name not set")
+	}
+}