Add Sec-WebSocket-Protocol to the HTTP header (#79)

This pull request adds support for the AMQP WebSocket subprotocol by including the `Sec-WebSocket-Protocol` header in WebSocket connections, and provides a complete example demonstrating AMQP 1.0 over WebSockets.

**Changes:**
- Added `Sec-WebSocket-Protocol: amqp` header to WebSocket connection initialization
- Created a comprehensive WebSocket example with queue declaration, message publishing, and consumption
- Added documentation for setting up and running the WebSocket example

Complete: #78
---------

Signed-off-by: Gabriele Santomaggio <G.santomaggio@gmail.com>

Author: Gsantomaggio

docs/examples/README.md

@@ -11,4 +11,5 @@
 - [Advanced Settings](advanced_settings) - An example of how to use the advanced connection settings of the AMQP 1.0 client.
 - [Broadcast](broadcast) - An example of how to use fanout to broadcast messages to multiple auto-deleted queues.
 - [RPC Echo](rpc_echo_server) - An example of how to implement RPC with the AMQP 1.0 client.
-- [SQL stream Filtering](sql_stream_filter) - An example of how to use SQL stream filtering with RabbitMQ Streams.
+- [SQL stream Filtering](sql_stream_filter) - An example of how to use SQL stream filtering with RabbitMQ Streams.
+- [Web Sockets](web_sockets) - An example of how to use Web Sockets with the AMQP 1.0 client.

docs/examples/web_sockets/README.md

@@ -0,0 +1,16 @@
+AMQP 1.0 over WebSocket Example
+===============================================================
+
+This example demonstrates how to use AMQP 1.0 over WebSocket. </br>
+## RabbitMQ Tanzu 
+You need [Tanzu RabbitMQ 4.0](https://www.vmware.com/products/app-platform/tanzu-rabbitmq) or later with the AMQP 1.0 and `rabbitmq_web_amqp` plugins enabled.
+
+For more info read the blog post: [AMQP 1.0 over WebSocket](https://www.rabbitmq.com/blog/2025/04/16/amqp-websocket)
+
+To run the example you need to have:
+- Tanzu RabbitMQ 4.0 or later with the AMQP 1.0 and `rabbitmq_web_amqp` plugins enabled.
+- A vhost called `ws` configured for WebSocket connections.
+- A user `rabbit` pwd `rabbit` with access to the `ws` vhost.
+
+## Web Sockify
+It is possible to run the example with [websockify](https://github.com/novnc/websockify)

docs/examples/web_sockets/web_sockets.go

@@ -0,0 +1,91 @@
+// RabbitMQ AMQP 1.0 Go Client: https://github.com/rabbitmq/rabbitmq-amqp-go-client
+// RabbitMQ AMQP 1.0 documentation: https://www.rabbitmq.com/docs/amqp
+// The example is demonstrating how to connect to RabbitMQ using AMQP 1.0 over WebSocket protocol with SASLTypePlain,
+// declare a queue, publish a message to it, and then consume that message.
+// AMQP 1.0 over WebSocket documentation: https://www.rabbitmq.com/blog/2025/04/16/amqp-websocket
+// example path: https://github.com/rabbitmq/rabbitmq-amqp-go-client/tree/main/docs/examples/web_sockets/web_sockets.go
+
+package main
+
+import (
+	"context"
+
+	"github.com/Azure/go-amqp"
+	rmq "github.com/rabbitmq/rabbitmq-amqp-go-client/pkg/rabbitmqamqp"
+)
+
+func main() {
+	const amqpConnectionString = "ws://127.0.0.1:15678/ws"
+	rmq.Info("[Example]", "Starting web socket connection to", amqpConnectionString)
+	// for anonymous connection use:
+	// env := rmq.NewEnvironment(amqpConnectionString, &rmq.AmqpConnOptions{
+	// 	SASLType: amqp.SASLTypeAnonymous(),
+	// })
+	env := rmq.NewEnvironment(amqpConnectionString, &rmq.AmqpConnOptions{
+		SASLType: amqp.SASLTypePlain("rabbit", "rabbit"),
+	})
+	conn, err := env.NewConnection(context.Background())
+	if err != nil {
+		panic(err)
+	}
+	_, err = conn.Management().DeclareQueue(context.TODO(), &rmq.QuorumQueueSpecification{
+		Name: "test-ws-queue",
+	})
+	if err != nil {
+		panic(err)
+	}
+	// declare new producer
+	producer, err := conn.NewPublisher(context.TODO(), &rmq.QueueAddress{
+		Queue: "test-ws-queue",
+	}, nil)
+	if err != nil {
+		panic(err)
+	}
+	msg := rmq.NewMessage([]byte("Hello over WebSockets"))
+
+	publishResult, err := producer.Publish(context.Background(), msg)
+	if err != nil {
+		panic(err)
+	}
+	switch publishResult.Outcome.(type) {
+	case *rmq.StateAccepted:
+		rmq.Info("[Publisher]", "Message accepted", publishResult.Message.Data[0])
+	default:
+		rmq.Warn("[Publisher]", "Message not accepted", publishResult.Message.Data[0])
+	}
+
+	// declare new consumer
+	consumer, err := conn.NewConsumer(context.TODO(), "test-ws-queue", nil)
+	if err != nil {
+		panic(err)
+	}
+	deliveryContext, err := consumer.Receive(context.Background())
+	if err != nil {
+		panic(err)
+	}
+	rmq.Info("[Consumer]", "Message received", string(deliveryContext.Message().GetData()))
+	err = deliveryContext.Accept(context.Background())
+	if err != nil {
+		panic(err)
+	}
+	// clean up
+	err = consumer.Close(context.TODO())
+	if err != nil {
+		panic(err)
+	}
+	err = producer.Close(context.TODO())
+	if err != nil {
+		panic(err)
+	}
+
+	err = conn.Management().DeleteQueue(context.Background(), "test-ws-queue")
+	if err != nil {
+		panic(err)
+	}
+
+	err = conn.Close(context.TODO())
+	if err != nil {
+		panic(err)
+	}
+
+}

pkg/rabbitmqamqp/amqp_connection.go

@@ -754,14 +754,18 @@ func sanitizeWebSocketURL(rawURL string) (string, http.Header, error) {
 
 	// Prepare Headers for Auth
 	headers := http.Header{}
+	// add sec-websocket-protocol amqp
+	// mandatory for AMQP over WebSocket
+	// https://www.rfc-editor.org/rfc/rfc6455.html
+	headers.Add("Sec-WebSocket-Protocol", "amqp")
+
 	if u.User != nil {
 		username := u.User.Username()
 		password, _ := u.User.Password()
 
 		// Construct Basic Auth Header manually
 		auth := base64.StdEncoding.EncodeToString([]byte(username + ":" + password))
 		headers.Add("Authorization", "Basic "+auth)
-
 		u.User = nil
 	}