I've tried localstack once a few months ago to mock SQS and found it really slow to boot, had a pretty high memory footprint, crashed very often (was running inside their official docker container I recall), and lacked documentation.

If you just need to mock SQS, I recommend using elasticmq. I've used it for a few months now and haven't had any problems at all so far.

https://github.com/adamw/elasticmq/blob/master/README.md https://hub.docker.com/r/expert360/elasticmq/