Forward host environment variables to the emulator container

[gtsiolis]

Forwards two sets of host environment variables into the LocalStack container at startup, matching the behaviour of the legacy CLI:

• CI: ensures LocalStack behaves correctly in CI environments.
• LOCALSTACK_*: forwards all LocalStack configuration variables set on the host. LOCALSTACK_AUTH_TOKEN is excluded since it is already explicitly injected.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI (base), Organization UI (inherited)

Review profile: CHILL

Plan: Pro

Run ID: b2fca232-5648-49b5-9927-bf1caaf8cf83

📥 Commits

Reviewing files that changed from the base of the PR and between 1384ec6 and 2d8e0ec.

📒 Files selected for processing (3)

• internal/container/start.go
• internal/container/start_test.go
• test/integration/start_test.go

📝 Walkthrough

Walkthrough

Host environment variables with prefix CI= or LOCALSTACK_ (except LOCALSTACK_AUTH_TOKEN=) are collected from os.Environ() and appended to each container's environment during Start. Tests added/updated to verify CI forwarding and ensure response bodies are closed via a deferred noop close.

Changes

Cohort / File(s)	Summary
Environment Variable Forwarding internal/container/start.go, internal/container/start_test.go	Collects host env entries matching CI= and LOCALSTACK_ (excluding LOCALSTACK_AUTH_TOKEN=) and appends them to each container's computed env during Start. Adds TestForwardCIEnvVariable to validate forwarding behavior.
Integration test cleanup test/integration/start_test.go	Replaced direct defer resp.Body.Close() with defer func() { _ = resp.Body.Close() }() in HTTP/HTTPS subtests to explicitly ignore Close errors after assertions.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• Mount Docker socket and add service port range #103 — Modifies container environment and startup wiring (injects DOCKER_HOST, GATEWAY_LISTEN, MAIN_CONTAINER_NAME); related to container env setup changes.

Suggested reviewers

• carole-lavillonniere
• anisaoshafi

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: forwarding host environment variables to the container, which matches the primary purpose of the changeset.
Description check	✅ Passed	The description accurately explains the changeset: it documents the forwarding of CI and LOCALSTACK_* variables to match legacy CLI behavior, which directly relates to the code changes.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch george/des-184

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@internal/container/start_test.go`:
- Line 72: Replace the unchecked defer os.Setenv("CI", originalCI) with a
t.Cleanup that restores the env and handles errors: inside the test (in
start_test.go) register t.Cleanup(func() { if err := os.Setenv("CI",
originalCI); err != nil { t.Fatalf("failed to restore CI env: %v", err) } }) so
the environment is restored reliably and the error from os.Setenv is not
ignored; alternatively, if available use t.Setenv to manage the variable
automatically.
- Around line 85-103: The test is rebuilding the env-forwarding logic instead of
exercising the real implementation and also ignores the os.Setenv error; extract
the host environment collection into a testable function (e.g., collectHostEnv
in start.go) that iterates os.Environ() and filters entries with
strings.HasPrefix(e, "CI=") or the LOCALSTACK_ rules, update Start to call
collectHostEnv, then rewrite the test to call collectHostEnv directly (in
start_test.go) and assert presence/absence of "CI=" using strings.HasPrefix
checks; also handle os.Setenv/os.Unsetenv return values (check and/or use
t.Cleanup and os.LookupEnv to restore original state) so no env-setting errors
are ignored.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI (base), Organization UI (inherited)

Review profile: CHILL

Plan: Pro

Run ID: 892049f8-b49a-4036-8d20-0d575e08580c

📥 Commits

Reviewing files that changed from the base of the PR and between 87a0335 and d784aba.

📒 Files selected for processing (2)

• internal/container/start.go
• internal/container/start_test.go

[carole-lavillonniere]

It looks good!

[gtsiolis]

Thanks for taking another look, @carole-lavillonniere! Rebased to run checks again. ⏳

[gtsiolis]

@carole-lavillonniere the integration tests were previously failing[1].

Tried to extract the host in a811f69.

Checks are now green, but let me know if this still looks good. 🍵