🚧 Apache Airflow Go Task SDK 🚧

[!NOTE] This Golang SDK is under active development and is not ready for prime-time yet.

This README is primarily aimed at developers working on the Go-SDK itself. Users wishing to write Airflow tasks in Go should look at the reference docs, but those don't exist yet.

How It Works

The Go SDK uses the Task Execution Interface (TEI or Task API) introduced in AIP-72 with Airflow 3.0.0.

The Task API however does not provide a means to get the ExecuteTaskWorkload to the go worker itself. For the short term, we make use of gopher-celery to get tasks from a Redis broker. Longer term we will likely need to stabilize the Edge Executor API and write a go client for that.

Since Go is a compiled language (putting aside projects such as YAEGI that allow go to be interpreted) all tasks must be a) compiled in to the binary, and b) “registered” inside the worker process in order to be executed.

Quick Testing Setup

The Go SDK currently works with Airflow‘s Celery Executor setup. Here’s how to get started:

Prerequisites

Go 1.21 or later
Docker and Docker Compose (for Breeze)
Redis (for Celery broker)

Step 1: Start Airflow with Celery Executor

Start Breeze with Celery executor:

breeze start-airflow --backend postgres --executor CeleryExecutor --load-example-dags

This will start:

Airflow API Server on http://localhost:28080
Celery workers (we will not utilise this)
Redis broker on localhost:26379
Loads the example DAGs

Step 2: Stop the Celery Worker

We want to run the go workers instead of running the Celery ones. So in breeze, press CTRL+C to stop the Celery workers.

Step 3: Run the Go SDK Worker

From the go-sdk directory, run the example worker:

go run ./example/main.go run \
  --broker-address=localhost:26379 \
  --queues default \
  --execution-api-url http://localhost:28080/execution

Parameters explained:

--broker-address=localhost:26379: Redis broker address (default Celery broker)
--queues default: Queue name where Celery enqueues tasks
--execution-api-url http://localhost:28080/execution: Airflow's Task Execution API endpoint

Step 4: Submit a Test Task

You can submit tasks through the Airflow UI for dag_id: tutorial_dag. The Go worker will pick up tasks from the Celery queue and execute them using the Task Execution Interface.

Observe the logs in the terminal where you run the test task.

Current state

This SDK currently will:

Get tasks from Celery queue(s)
Run registered tasks (no support for dag versioning or loading of multiple different “bundles”)
Heartbeat and report the final state of the final TI
Allow access to Variables

Known missing features

A non-exhaustive list of features we have yet to implement

Reading of Airflow Connections
Support for putting tasks into state other than success or failed/up-for-retry (deferred, failed-without-retries etc.)
HTTP Log server to view logs from in-progress tasks
Remote task logs (i.e. S3/GCS etc)
XCom reading/writing from API server
XCom reading/writing from other XCom backends

Future Direction

This is more of an “it would be nice to have” than any plan or commitment, and a place to record ideas.

Support multiple versions by compiling tasks/bundles into plugins and make use of go-plugin (This is how Terraform providers work)
This would enable use to have executor code and task code in separate processes, and to be able to have a single worker execute different bundles/versions of tasks (i.e. we'd have a go executor process that launches versioned plugin bundles to actually execute the task)