CI: run LocalStack via lstk instead of the localstack PyPI package

[silv-io]

Motivation

The release workflow installs localstack==${RELEASE_VERSION} from PyPI just to start LocalStack for the SDK tests. This couples the SDK release to the localstack package release (published separately via localstack-cli-standalone, with no retry on PyPI propagation lag) and stands in the way of the planned deprecation of that package. The pinned Docker image is the actual dependency; the pip package is only the launcher.

Changes

• release.yml: install lstk via npm instead of pip install localstack==$VERSION; pin the emulator image through an lstk config file in $RUNNER_TEMP (outside the workspace, so the "Check Uncommitted Changes" gate stays clean). lstk start --timeout 2m replaces start -d + wait — it blocks until the emulator is healthy and dumps startup logs itself on failure. logs/stop pass the same --config, since the derived container name embeds the pinned tag.
• test.yml: same swap, no config file needed — lstk defaults to localstack/localstack-pro:latest.
• DEBUG/DISABLE_EVENTS become LOCALSTACK_DEBUG/LOCALSTACK_DISABLE_EVENTS (lstk forwards LOCALSTACK_* host env vars into the container).

The Docker image pull remains the only release-time dependency on LocalStack itself.

Testing

Verified locally with lstk built from latest main: the exact pinned-style config plus lstk --config … start --timeout 2m / logs / stop all pass, with DEBUG output visible in the logs (env forwarding works). The test.yml path runs on this PR; the release.yml path is first exercised on the next release.

Review

Workflow-only change. Worth a skim of the release.yml diff since that path only runs during an actual release. Notes for reviewers: port is required in an lstk [[containers]] block (omitting it fails validation), and a tag the license server can't parse degrades to in-container license validation instead of failing the start.

Closes COSY-856

🤖 Generated with Claude Code

[aidehn]

out of curiosity is it possible at all to change the chosen image without using the config ?

[silv-io]

Our decision back then was to consciously have the main way of doing this be the config file.

Could be that we added option overrides since then, but IMO both locally and in CI it's better to just have a clear file that defines your setup vs. attaching an increasing list of CLI parameters to your call.

[aidehn]

LGTM! Tests are passing so looks good! Thanks for picking this up - it means once we move away from the localstack CLI in our release there's less for us to do!

[aidehn]

hopefully at some point lstk releases a github action? 👀

[silv-io]

setup-localstack should probably handle the install in the future, yeah