feat(build): improve performance and reliability of devcontainer launch (#977)

[stewartadam]

Pull Request

Description

Captures learnings from recent customer projects to enhance the build speed and launch reliability of the dev container.

• removes unused Python feature from container, which was causing compilation of Python on build
• add volume mounts for node_modules and user config for better I/O performance
• normalize workspace mount to /workspace for consistency across environments
• add CA certificate injection for corporate TLS inspection (ZScaler, etc.)
• add git config include parsing workaround for devcontainer identity issues

Related Issue(s)

Type of Change

Select all that apply:

Code & Documentation:

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Infrastructure & Configuration:

• GitHub Actions workflow
• Linting configuration (markdown, PowerShell, etc.)
• Security configuration
• DevContainer configuration
• Dependency update

AI Artifacts:

• Reviewed contribution with prompt-builder agent and addressed all feedback
• Copilot instructions (.github/instructions/*.instructions.md)
• Copilot prompt (.github/prompts/*.prompt.md)
• Copilot agent (.github/agents/*.agent.md)
• Copilot skill (.github/skills/*/SKILL.md)

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Testing

Checklist

Required Checks

• Documentation is updated (if applicable)
• Files follow existing naming conventions
• Changes are backwards compatible (if applicable)
• Tests added for new functionality (if applicable)

AI Artifact Contributions

• Used /prompt-analyze to review contribution
• Addressed all feedback from prompt-builder review
• Verified contribution follows common standards and type-specific requirements

Required Automated Checks

The following validation commands must pass before merging:

• Markdown linting: npm run lint:md
• Spell checking: npm run spell-check
• Frontmatter validation: npm run lint:frontmatter
• Skill structure validation: npm run validate:skills
• Link validation: npm run lint:md-links
• PowerShell analysis: npm run lint:ps
• Plugin freshness: npm run plugin:generate

Security Considerations

• This PR does not contain any sensitive or NDA information
• Any new dependencies have been reviewed for security issues
• Security-related scripts follow the principle of least privilege

Additional Notes

[stewartadam]

Follow up to #119.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.01%. Comparing base (c2b806f) to head (8bd6188).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #472   +/-   ##
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  Coverage   88.01%   88.01%           
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  Files          45       45           
  Lines        7886     7886           
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  Hits         6941     6941           
  Misses        945      945           

Flag	Coverage Δ
pester	86.91% <ø> (ø)

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[Copilot]

Pull request overview

Improves devcontainer build/attach performance and reliability by removing unneeded features, standardizing the workspace path, and adding volume mounts and git-config handling for better cross-environment behavior.

Changes:

• Standardize devcontainer workspace to /workspace and add volumes for user config + node_modules.
• Add post-create ownership workaround for mounted volumes and a post-attach git identity reconfiguration step.
• Add repository-level ignores/attributes to support the new devcontainer flow (gitconfig exports, dockerignore, line ending rules).

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
.gitignore	Ignores generated gitconfig export files used by the devcontainer attach workaround.
.gitattributes	Adds explicit checkout line-ending rules for scripts and Dockerfiles.
.dockerignore	Excludes .git and node_modules from Docker build contexts for speed/smaller contexts.
.devcontainer/scripts/post-create.sh	Adds volume ownership fix step and installs Node dependencies during container setup.
.devcontainer/scripts/post-attach.sh	Applies exported git identity settings inside the container after attach.
.devcontainer/devcontainer.json	Normalizes workspace mount/folder, adds volumes, removes unused features, and wires initialize/postAttach commands.
.devcontainer/README.md	Updates documented toolset and troubleshooting guidance to match the new devcontainer behavior.

[WilliamBerryiii]

Looking sharp

[WilliamBerryiii]

@stewartadam - reverting to draft for now.

[WilliamBerryiii]

Hey @stewartadam — thanks for capturing these devcontainer learnings from customer projects! 🚀 We've updated the PR title scope from devcontainer to build to align with our conventional commits conventions. No action needed on your end.

[WilliamBerryiii]

We've updated the PR description to align with the current pull request template. All original content has been preserved and relocated into the appropriate template sections. No action needed on your end — though you're welcome to review the updated description and fill in any remaining sections (testing details, checklist confirmations, etc.) at your convenience.

[WilliamBerryiii]

Hi @stewartadam — Thanks for this contribution! A quick note on project conventions: we ask that pull requests be paired with a corresponding backlog issue for tracking purposes. I wasn't able to find an existing issue related to devcontainer performance and reliability improvements.

When you get a chance, could you file an issue describing the changes this PR addresses and link it here using Closes #NNN in the PR body? This helps the team track work across the backlog and ensures issues are automatically closed when PRs merge. Thanks! 🙏

[stewartadam]

Created #977 and updated based on feedback