Question: How best do I carry out a health check?

[definite-d]

Streaq is great; I tried it straight from the comment about it in arq's repo, and it quickly became my default for any Python projects.

However, when paired with an API, of course the worker process has to start (and be ready) first. Using Docker Compose, one can set "dependencies" on other services, requiring that some are started and healthy before the others. That in turn needs a health check, like how PostgreSQL has pg_isready.

So I ask: what do you, the creators of the library, consider the best way to perform this health check in Streaq? I also believe the solution should be properly documented in the docs.

[Graeme22]

Interesting question! Workers set healthiness periodically in Redis, the key is streaq:{QUEUE_NAME}:health:{WORKER_ID}. So you could just poll this key--however, that assumes you know what the worker ID is beforehand. You could use a custom worker ID, but you'd have to be careful with this as if it were just a constant string the health key could persist from one run to the next. You could also try to parse the random ID out of the logs.

If that doesn't work well I'm open to alternatives as long as they only require minimal changes.