Extract Commit Action

A powerful GitHub Action that extracts and processes information from commit messages using customizable patterns and commands.

Features

• Flexible Pattern Matching: Extract information using regex patterns or custom commands
• Multiple Output Formats: Support for text, JSON, and CSV outputs
• Customizable Depth: Control the number of commits to analyze
• Fast & Lightweight: Built with Python 3.14-slim for optimal performance
• Fail-Safe Options: Optional validation with fail_on_empty
• Pretty Formatting: Clean, formatted commit message output
• Debug Mode: Verbose output for troubleshooting
• Timeout Control: Prevent long-running operations
• Easy Integration: Simple YAML configuration in your workflows

Quick Start

- name: Extract Environment from Commits
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'env:(\\w+)'"
    pretty: true
    key_variable: 'DEPLOY_ENV'

Inputs

Input	Description	Required	Default
commit_limit	Number of commits to retrieve	Yes	N/A
extract_command	Command to extract info (e.g., grep pattern)	No	N/A
pretty	Use pretty format for Git logs	No	false
key_variable	Name of the output variable	No	ENVIRONMENT
fail_on_empty	Fail if no information is extracted	No	false
output_format	Output format: text, json, or csv	No	text
debug	Enable debug mode for verbose output	No	false
timeout	Timeout in seconds for git/extract commands	No	30

Outputs

Output	Description
key_variable	The name of the variable used
value_variable	The extracted value(s) from commits

Common Use Cases

Extract Environment Information

- name: Extract Environment
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'env:(\\w+)'"
    pretty: true
    key_variable: 'DEPLOY_ENV'

Find Feature Tags

- name: Extract Feature Tags
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'feature:(\\w+)'"
    key_variable: 'FEATURE_TAG'

Extract Version Numbers

- name: Extract Version
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'v[0-9]+\\.[0-9]+\\.[0-9]+'"
    key_variable: 'VERSION'

Fail on Empty Results

- name: Extract Critical Changes
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'critical:(\\w+)'"
    key_variable: 'CRITICAL_CHANGES'
    fail_on_empty: true  # Fails if no matches found

Extract JIRA Tickets with JSON Output

- name: Extract JIRA Tickets
  id: jira
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 20
    extract_command: "grep -oE 'JIRA-[0-9]+'"
    key_variable: 'JIRA_TICKETS'
    output_format: 'json'

- name: Process Tickets
  run: |
    echo '${{ steps.jira.outputs.value_variable }}' | jq -r '.[]'

Debug Mode for Troubleshooting

- name: Extract with Debug
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'env:(\\w+)'"
    key_variable: 'ENVIRONMENT'
    debug: true          # Enable verbose output
    timeout: 60          # Set custom timeout

Output Formats

The action supports three output formats:

Format	Description	Example Output
text	Plain text (default)	value1 value2 value3
json	JSON array	["value1", "value2", "value3"]
csv	Comma-separated	value1,value2,value3

Format Examples

Given extracted values: JIRA-123, JIRA-456, JIRA-789

Text format:

JIRA-123
JIRA-456
JIRA-789

JSON format:

["JIRA-123", "JIRA-456", "JIRA-789"]

CSV format:

JIRA-123,JIRA-456,JIRA-789

Extract Command Examples

Purpose	Command	Example Match
Environment	grep -oE 'env:(\\w+)'	env:production
Fix IDs	grep -oE 'fix-[0-9]+'	fix-123
Versions	grep -oE 'v[0-9]+\\.[0-9]+\\.[0-9]+'	v1.2.3
Features	grep -oE 'feature:(\\w+)'	feature:login
JIRA IDs	grep -oE 'JIRA-[0-9]+'	JIRA-456
Conventional Commits	`grep -oE '^(feat	fix

Note: Use grep -oE (Extended regex) instead of grep -oP (Perl regex) for better compatibility.

Best Practices

Commit Message Format

• Use consistent commit message formats (e.g., Conventional Commits)
• Include relevant tags or identifiers
• Example: feat(auth): add login functionality env:production

Extraction Patterns

• Test regex patterns locally before implementation:

  echo "feat: add login env:production" | grep -oE 'env:(\\w+)'

• Use specific patterns to avoid false matches
• Consider edge cases and special characters

Performance

• Set appropriate commit_limit based on your needs
• Lower values = faster execution
• Typical range: 10-50 commits

Repository Setup

• Ensure sufficient fetch-depth in checkout action:

  - uses: actions/checkout@v4
    with:
      fetch-depth: 20  # Match or exceed commit_limit

Troubleshooting

No Matches Found

Problem: Action completes but returns empty results

Solutions:

1. Verify commit messages contain expected patterns:

   git log -10 --pretty=%B

2. Test your regex pattern locally:

   git log -10 --pretty=%B | grep -oE 'your-pattern'

3. Ensure fetch-depth in checkout is sufficient
4. Check if fail_on_empty is set appropriately

Incorrect Matches

Problem: Extracting wrong or unexpected values

Solutions:

• Review and refine your regex pattern
• Use more specific patterns with word boundaries
• Test with sample commit messages first
• Use online regex testers like regex101.com

Action Fails with Error

Problem: Action exits with non-zero code

Possible Causes:

• fail_on_empty: true is set and no matches found (intended behavior)
• Invalid regex pattern in extract_command
• Git repository not available
• Insufficient permissions

Debug Steps:

- name: Debug Commit Messages
  run: git log -${{ inputs.commit_limit }} --pretty=%B

- name: Test Extract Command
  run: |
    git log -10 --pretty=%B | grep -oE 'your-pattern' || echo "No matches"

# Or use built-in debug mode
- name: Extract with Debug Mode
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'your-pattern'"
    debug: true  # Shows detailed execution information

Timeout Errors

Problem: Action times out during execution

Solutions:

• Increase timeout value (default is 30 seconds):

  - uses: somaz94/commit-info-extractor@v1
    with:
      commit_limit: 10
      extract_command: "complex-command"
      timeout: 120  # Increase to 2 minutes

• Reduce commit_limit to process fewer commits
• Simplify your extract_command pattern

Advanced Usage

Processing Multiple Matches

When multiple values are extracted, you can process them in subsequent steps:

Text format:

- name: Extract JIRA Tickets
  id: extract
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'JIRA-[0-9]+'"
    key_variable: 'JIRA_TICKETS'

- name: Process Each Ticket
  run: |
    while IFS= read -r ticket; do
      echo "Processing: $ticket"
      # Your processing logic here
    done <<< "${{ steps.extract.outputs.value_variable }}"

JSON format:

- name: Extract as JSON
  id: extract_json
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 10
    extract_command: "grep -oE 'JIRA-[0-9]+'"
    output_format: 'json'

- name: Process JSON Array
  run: |
    echo '${{ steps.extract_json.outputs.value_variable }}' | \
      jq -r '.[]' | while read -r ticket; do
        echo "Processing: $ticket"
      done

Combining with Other Actions

Send to Slack:

- name: Extract Deployment Info
  id: deploy
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 5
    extract_command: "grep -oE 'env:(\\w+)'"
    key_variable: 'ENVIRONMENT'

- name: Notify Slack
  uses: slackapi/slack-github-action@v1
  with:
    payload: |
      {
        "text": "Deploying to: ${{ steps.deploy.outputs.value_variable }}"
      }

Conditional Deployment:

- name: Check for Production Tag
  id: check_env
  uses: somaz94/commit-info-extractor@v1
  with:
    commit_limit: 1
    extract_command: "grep -oE 'env:production'"
    fail_on_empty: false

- name: Deploy to Production
  if: steps.check_env.outputs.value_variable == 'env:production'
  run: |
    echo "Deploying to production..."

Security Considerations

When using this action, keep the following in mind:

Command Injection Prevention

• The extract_command executes shell commands
• Never use untrusted user input in extraction commands
• Always validate and sanitize inputs

Sensitive Information

• Be careful not to extract secrets or credentials from commit messages
• Use GitHub's secret scanning alongside this action
• Consider filtering sensitive patterns

Permission Scopes

• This action only requires read access to repository content
• Follow the principle of least privilege in your workflows

Local Testing

Test the Python script locally without Docker:

# Clone the repository
git clone https://github.com/somaz94/commit-info-extractor.git
cd commit-info-extractor

# Run tests
python3 tests/test_local.py

# Or test manually
export INPUT_COMMIT_LIMIT=10
export INPUT_EXTRACT_COMMAND="grep -oE 'feat|fix|chore'"
export INPUT_PRETTY=true
export INPUT_DEBUG=true      # Enable debug mode
export INPUT_TIMEOUT=60       # Set timeout
python3 entrypoint.py

See tests/TESTING.md for more details.

Changelog

See CHANGELOG.md for version history and updates.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to:

• Report bugs
• Suggest new features
• Submit pull requests
• Improve documentation

Support

If you find this action helpful, please consider:

• Starring the repository
• Sharing with others
• Contributing improvements

Related Projects

• actions/checkout - Checkout your repository
• github-script - Write workflows using JavaScript
• setup-python - Set up Python environment

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Made by somaz94