fix(build): use NGX_WASM_MODULE_BRANCH environment variable

[locao]

Summary

To improve the development and testing experience of the integration between Kong and Wasmx, the NGX_WASM_MODULE_BRANCH environment variable should be used to overwrite the ngx_wasm_module branch/commit in the .requirements file, as it is documented in build/README.md. But this variable was being ignored by the build system.

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

KAG-3396

[flrgh]

Looks good to me as long as it's working!

Are there any caveats to this with regards to bazel's caching that should be documented? i.e. Do I need to manually purge the cache when changing NGX_WASM_MODULE_BRANCH?

[locao]

Are there any caveats to this with regards to bazel's caching that should be documented?

Yes, after the first build NGX_WASM_MODULE_REMOTE and NGX_WASM_MODULE_BRANCH changes are ignored by the build system, but this issue is already documented.

[hishamhm]

Yes, after the first build NGX_WASM_MODULE_REMOTE and NGX_WASM_MODULE_BRANCH changes are ignored by the build system, but this issue is already documented.

If I keep those variables unchanged but change the actual code in the branch between runs, does it require a purge as well?

[fffonion]

the environ variable should be added to https://github.com/Kong/kong/pull/12241/files#diff-2cc0f6ace9a475cc6da6de926e8eabbe69e8b7e6e5c4fb721ec83d59f3f04725R113 here to evict cache (of the kong_bindings.bzl file/repository only)

[hishamhm]

@locao could we get @fffonion's suggested addition in as well, to make the cache work correctly? 🙏

[RobSerafini]

@fffonion - can you re-review this now?

[thibaultcha]

"chore"?

[locao]

I agree it would be a better option, but it is not one of the types available in the new changelog format.

[team-gateway-bot]

Cherry-pick failed for master, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git remote add upstream https://github.com/kong/kong-ee
git fetch upstream master
git worktree add -d .worktree/cherry-pick-12241-to-master-to-upstream upstream/master
cd .worktree/cherry-pick-12241-to-master-to-upstream
git checkout -b cherry-pick-12241-to-master-to-upstream
ancref=$(git merge-base 36c3836326d29444b400d45d7e6cdcba67f065a6 23e6aa078b29ddb325d57d7905f1a68c47fa489f)
git cherry-pick -x $ancref..23e6aa078b29ddb325d57d7905f1a68c47fa489f