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Running Pre-commit Hooks for Repository Maintenance

Overview

Pre-commit hooks are scripts or actions that run before a commit is made in a version control system like Git. They allow you to enforce certain standards, checks, or tests on your code before it gets committed. Here's how you can set up pre-commit hooks specifically for Terraform using the popular tool pre-commit.

Available Pre-commit Hooks

1. yamllint

  • Purpose: Lint YAML files to enforce coding standards.
  • Example: Enforces a maximum line length of 200 characters in YAML files.

2. pre-commit-hooks

  • Purpose: Provides a collection of commonly used pre-commit hooks.
  • Examples:
    • check-yaml: Ensures YAML files are well-formed.
    • check-merge-conflict: Checks for merge conflict markers.
    • trailing-whitespace: Removes trailing whitespaces.
    • end-of-file-fixer: Ensures files end with a newline.

3. pre-commit-terraform

  • Purpose: Manages Terraform-specific pre-commit hooks.
  • Examples:
    • terraform_validate: Validates Terraform files.
    • terraform_tflint: Lints Terraform files.
    • terraform_fmt: Formats Terraform files recursively.
    • terraform_docs: Updates Terraform documentation.

Installation and Usage

  1. Ensure the .pre-commit-config.yaml file is present in the root of your repository.

  2. Install pre-commit using the following terminal command:

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    pre-commit install

  3. With pre-commit installed, the defined hooks will run automatically before each commit.

  4. After making necessary changes to YAML, Terraform files, or Terraform docs, use the following commands:

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    git add .
git commit -m "Your commit message"

  5. The pre-commit hooks will execute, identifying any linting or formatting issues.

  6. If the hooks suggest changes, address them and repeat steps 4 and 5 until no issues are reported.

Importance of Pre-commit Hooks

  • Consistency: Ensures consistent coding style across all contributors.
  • Automated Checks: Identifies issues early in the development process, preventing them from reaching the repository.
  • Documentation Maintenance: Keeps Terraform documentation up-to-date automatically.

By integrating these pre-commit hooks into your workflow, you enhance the overall code quality and maintain a clean and standardized codebase.