Azure Storage Queue native integration sample

This document describes how to consume messages from and send messages to non-NServiceBus endpoints via Azure Storage Queues in integration scenarios.

Sending native messages

Sending native messages can be accomplished by sending a message with a JSON-serialized payload using the QueueClient. Refer to the sample for more information.

Custom envelope wrapper

Azure Storage Queues lacks native header support. NServiceBus solves this by wrapping headers and message body in a custom envelope structure. This envelope is serialized using the configured serializer for the endpoint before being sent.

Creating this envelope can cause unnecessary complexity if headers are not needed, for example, in native integration scenarios. For this reason, NServiceBus.Transport.AzureStorageQueues 9.0 and above support configuring a custom envelope unwrapper.

The snippet below shows custom unwrapping logic that enables both NServiceBus formatted and plain JSON messages to be consumed.

var transport = endpointConfiguration.UseTransport<AzureStorageQueueTransport>();

transport.UnwrapMessagesWith(queueMessage =>
{
    using (var stream = new MemoryStream(Convert.FromBase64String(queueMessage.MessageText)))
    using (var streamReader = new StreamReader(stream))
    using (var textReader = new JsonTextReader(streamReader))
    {
        //try deserialize to a NServiceBus envelope first
        var wrapper = jsonSerializer.Deserialize<MessageWrapper>(textReader);

        if (wrapper.Id != null)
        {
            //this was a envelope message
            return wrapper;
        }

        //this was a native message just return the body as is with no headers
        return new MessageWrapper
        {
            Id = queueMessage.MessageId,
            Headers = new Dictionary<string, string>(),
            Body = Convert.FromBase64String(queueMessage.MessageText)
        };
    }
});