fix(aws): use mutex for deployment-etag cache

[lionello]

Description

Fix panic when receiving ECS events from different go routines.
Untitled.txt

Linked Issues

Checklist

• I have performed a self-review of my code
• I have added appropriate tests
• I have updated the Defang CLI docs and/or README to reflect my changes, if necessary

Summary by CodeRabbit

Release Notes

• Refactor

  • Updated internal event handling interfaces for improved type consistency and safety across cloud infrastructure modules.
  • Refactored cache implementation to support concurrent access with thread-safe operations.

• Chores

  • Enhanced debug logging for error diagnostics in session management.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: c0257439-970f-485f-8b32-15078af131be

📥 Commits

Reviewing files that changed from the base of the PR and between 22cc444 and c51d2a2.

📒 Files selected for processing (3)

• src/cmd/cli/command/session.go
• src/pkg/clouds/aws/codebuild/event.go
• src/pkg/clouds/aws/ecs/event.go

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📝 Walkthrough

Walkthrough

The pull request updates AWS event handling to use typed types.ETag instead of plain strings across CodeBuild and ECS implementations. Additionally, the ECS cache is refactored from a map alias to a mutex-guarded struct for thread-safety. A debug log is added to session initialization for error reporting.

Changes

Cohort / File(s)	Summary
Session Initialization Logging src/cmd/cli/command/session.go	Added debug log emission when loader.ProjectWorkingDir(ctx) fails in newStackManagerForLoader, maintaining existing fallback behavior.
CodeBuild Event Interface src/pkg/clouds/aws/codebuild/event.go	Updated Event interface and CodebuildEvent implementation to return types.ETag instead of string in Etag() method signature.
ECS Event and Cache Refactoring src/pkg/clouds/aws/ecs/event.go	Converted Cache interface to use types.ETag, refactored LocalCache from map alias to struct with sync.RWMutex for thread-safety, updated DeploymentEtags initialization, and changed all event types' Etag() signatures to return types.ETag.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related PRs

• CodeBuild event streaming #1809: Directly modifies the same CodeBuild event code that is updated here to use types.ETag.
• allow --provider to override default stack #1862: Updates session.go error handling with debug logging in a similar pattern to the ProjectWorkingDir failure reporting added here.
• fix: don't write file outside of refered project dir #1993: Modifies the same newStackManagerForLoader initialization path and ProjectWorkingDir usage in session.go.

Suggested reviewers

• jordanstephens
• edwardrf

Poem

🐰 Types now bloom with clarity bright,
ETag's no string, but typed just right!
Cache gains mutex, threads won't clash,
Etags flow swift through AWS bash! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding mutex protection to the deployment-etag cache in AWS ECS code, which aligns with the primary modification of converting LocalCache to a mutex-guarded struct.

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✨ Finishing Touches

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🧪 Generate unit tests (beta)

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📝 Coding Plan

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Warning

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🔧 golangci-lint (2.11.3)

level=warning msg="[linters_context] running gomodguard failed: unable to read module file go.mod: current working directory must have a go.mod file: if you are not using go modules it is suggested to disable this linter"
level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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