• 1. Introduction
• 2. How to use

Alton is a piece of middleware which will provide APIs to help manage your queues via your ops portal.

Alton is an ASP.NET Core piece of middleware that will automatically register routes on your behalf. Alton is still in a preview stage and some issues may arise.

Firstly, to register the middleware, you will need to add it to the service collection and register the middleware:

public void ConfigureServices(IServiceCollection services)
{
    services.AddAlton();
    //my other services here
}

The IServiceCollection.AddAlton() extension will automatically register an SqsClientResolver which will create an SQS client using the region parsed from the QueueUrl.

You can provide your own resolver with any delegate matching the signature:

IAmazonSQS Resolve(AltonQueueComponent queue);

public void Configure(IApplicationBuilder appBuilder)
{
    app.MapAlton(
        new AltonOptions
        {
            BaseRoute = "<api base route>",
            QueuesToManage = new Dictionary<string, AltonQueueComponent>
            {
                ["<Queue 1>"] = new()
                {
                    QueueUrl = settings.AltonQueueUrl,
                    DeadLetterQueueUrl = settings.AltonDlqUrl
                },
                ["<Queue 2>"] = new()
                {
                    QueueUrl = settings.AltonQueueUrl,
                    DeadLetterQueueUrl = settings.AltonDlqUrl
                }
                // etc...
            }
        },
    "AuthPolicyNameForTheseEndpoints", // This policy gets set in `.RequireAuthorization()`
    endpoint => endpoint.IncludeInOpenApi()); // This lets you customise the endpoints further

}

Base route defaults to /queue-management if not set.

Gets the overall state of the managed queues

GET /queue-states

[
    { 
    "Name": "internalQueue",
    "MessagesInQueue": 123,
    "MessagesInDeadLetterQueue": 456
    },
    { 
    "Name": "externalQueue",
    "MessagesInQueue": 789,
    "MessagesInDeadLetterQueue": 0
    }
]

Redrives all messages in a dead letter queue

POST /queues/<main queue name>/redrive-all

Returns:

No content

Retrieves messages from the dead letter queue. The messages will become invisible whilst the visibility timeout is still valid. Once the visibility timeout has lapsed, you will not be able to make individual actions on the messages.

POST /queues/<queue name>/retrieve-messages
Content-Type: application/json
{
    "VisibilityTimeout": 60
    "MaxNumberOfMessages": 10
}

Returns:

[
    {
      "Body": "the message body",
      "ReceiptHandle": "message-receipt-handle",
      "Attributes": [
                     {
                      "Key": "message-attribute-key",
                      "DataType": "String",
                      "Value": "my message attribute"
                     }]   
    },
    {
      "Body": "Another message body",
      "ReceiptHandle": "another-message-receipt-handle",
      "Attributes": [
                     {
                      "Key": "message-attribute-key",
                      "DataType": "String",
                      "Value": "my message attribute"
                     }]   
    }
]

Delete individual messages after retrieving them. Message receipt handle can be obtained from retrieve-messages POST request

DELETE /queues/<queue name>/messages
Content-Type: application/json
{
    "ReceiptHandle": "<message receipt handle>"
}

Returns:

No content

Deletes all messages in a dead letter queue

DELETE /queues/<queue name>

Returns:

No content