Asya separates message transport from application logic. The same handler code runs on any supported queue backend — swapping transports is an infrastructure change, not a code change.

Supported transports#

Transport is configuration, not code#

The handler function has no knowledge of the underlying queue. Transport selection happens in the AsyncActor manifest:

spec:
  transport:
    type: sqs
    queue: my-actor-queue

Changing from SQS to RabbitMQ means updating this YAML block. The handler, the sidecar behavior, and the scaling logic all remain identical.

Crossplane abstracts provisioning#

When using Crossplane Compositions, the queue itself is provisioned declaratively. Creating an AsyncActor resource automatically provisions the backing queue, configures KEDA scaling, and wires the sidecar to the correct endpoint.

Socket transport for local development#

The Socket transport uses Unix domain sockets for message passing. It requires no cloud credentials and no external services, making it ideal for local testing with Docker Compose.

Same actor, different environments#

A common pattern is to use Socket transport in development, RabbitMQ in staging, and SQS in production. The handler code is identical across all three — only the infrastructure configuration changes.

Transport interface#

Adding a new transport means implementing this Go interface (src/asya-sidecar/pkg/transport/transport.go):

type Transport interface {
    Receive(ctx context.Context, queueName string) (QueueMessage, error)
    Send(ctx context.Context, queueName string, body []byte) error
    SendWithDelay(ctx context.Context, queueName string, body []byte, delay time.Duration) error
    Ack(ctx context.Context, msg QueueMessage) error
    Requeue(ctx context.Context, msg QueueMessage) error
    Close() error
}

Each backend (SQS, RabbitMQ, Pub/Sub, Socket) provides its own implementation of this interface. The sidecar selects the implementation based on the transport.type field in the AsyncActor manifest.

Further reading#

• Transport reference — configuration details for each transport backend
• SQS transport, RabbitMQ transport, Pub/Sub transport — backend-specific setup