terraform-docs VS pre-commit

Documentation is really important, so having a README.md file inside your Terraform repository that explains how to use the automation (including descriptions of variables and outputs) really help in understanding what has been implemented. To easily generate the description of variables and outputs, you can leverage tfdocs.

‍Terraform-docs is a tool that automatically generates documentation from Terraform modules in various output formats, including markdown, JSON, and others. It's particularly useful for maintaining up-to-date documentation of your Terraform modules' inputs, outputs, providers, and resources.

Earlier this year I wrote about the challenges I faced creating a Terraform module. I mentioned then that I was leveraging terraform-docs and GitHub Actions to automate documentation, but a full workflow walkthrough was out of that post's scope.

### Muti-Stage pipeline for windows trigger: - main variables: terraformDocsVersion: '0.16.0' serviceConnectionName: 'Terraform-SPN-DevOps-MagiconionM' keyvaultName: 'pwd9000-core-kv' pool: vmImage: 'windows-latest' stages: - stage: GenerateTerraformDocumentation jobs: - job: Generate_Terraform_Documentation steps: - checkout: self persistCredentials: true # this allows the later scripts to use the system-provided git token to push changes back to the repo ### Link to key vault. - task: AzureKeyVault@1 inputs: azureSubscription: $(serviceConnectionName) #ADO service connection (Service principal) KeyVaultName: $(keyvaultName) SecretsFilter: 'TerraformDocsPAToken' RunAsPreJob: true displayName: Get PAToken from Keyvault ### Install Terraform-Docs. - powershell: | Invoke-WebRequest -Uri "https://github.com/terraform-docs/terraform-docs/releases/download/v$(terraformDocsVersion)/terraform-docs-v$(terraformDocsVersion)-windows-amd64.zip" -OutFile "terraform-docs.zip" Expand-Archive -Path "terraform-docs.zip" -DestinationPath "$(System.DefaultWorkingDirectory)\terraform-docs" -Force $env:Path += ";$(System.DefaultWorkingDirectory)\terraform-docs" displayName: 'Install terraform-docs' ### Remove all old README.md files and generate new README.md files for each TF module. - powershell: | # Set Modules Root Directory Set-Location "$(Build.SourcesDirectory)\@TF_Modules" # Get all subdirectories (Terraform module directories) $terraformModuleDirs = Get-ChildItem -Path (Get-Location) -Directory # Loop through each directory to cleanup/remove old README files foreach ($dir in $terraformModuleDirs) { # Get all files in the directory $readMeFiles = Get-ChildItem -Path $dir.FullName -Filter 'README.md' # Loop through each file in each terraform module foreach ($file in $readMeFiles) { # Check if README file already exists and remove if ($file) { # Remove the file Remove-Item $file.FullName -Confirm:$false Write-Output "Old file '$($file.Name)' removed from '$($dir.FullName)'" } } #After cleanup create a new README.md file with 'terraform-docs' based on latest TF module code in current folder(terraform module) $tfFiles = Get-ChildItem -Path $dir.FullName -Filter *.tf if ($tfFiles.Count -gt 0) { # Create new README.md file $(System.DefaultWorkingDirectory)\terraform-docs\terraform-docs.exe markdown table $dir.FullName --output-file "README.md" } else { Write-Output "No .tf files found." } } displayName: 'Cleanup and Generate new README for each TF module' ### Commit and push updated README.md files for TF modules. - powershell: | git config --local user.email "[email protected]" git config --local user.name "Terraform Docs" git add *.md git commit -m "Update README.md for each TF module" git push origin HEAD:$(Build.SourceBranchName) displayName: 'Commit and Push updated README.md files for TF modules' env: SYSTEM_ACCESSTOKEN: $(TerraformDocsPAToken)

I'm going to have to figure out how to run terraform-docs.io against each module. I have zero terraform experience.

Terraform-docs: This tool generates documentation for your Terraform modules in various formats, such as Markdown, HTML, and JSON. Terraform-docs parses your Terraform code and extracts documentation from comments, variable and output descriptions, and input/output examples. The tool then generates a table of contents with links to the relevant documentation for each module, which makes it easy to understand the purpose and usage of each module.

Terraform docs

I have been using https://terraform-docs.io to generate documentation of my terraform modules. However creating nested objects with optionals makes the documentation rather ugly and hard to read. See gh issue which also describes this type of issue: https://github.com/terraform-docs/terraform-docs/issues/656

I am looking for a way to automate doc creation and updates for ansible roles. I recently discovered terraform-docs and I am curious if there is something similar for ansible.

terraform-docs: https://github.com/terraform-docs/terraform-docs

Do you have other Terraform-related open-source tools that you recommend? Please go ahead and add in the comments!

Today we are going to look at how to setup Black (a python code formatter) and pre-commit (a package for handling git hooks in python) to automatically format you code on commit.

# See https://pre-commit.com for more information # See https://pre-commit.com/hooks.html for more hooks repos: - repo: https://github.com/pre-commit/pre-commit-hooks rev: v3.2.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-yaml - id: check-toml - id: check-added-large-files - repo: local hooks: - id: tox lint name: tox-validation entry: pdm run tox -e test,lint language: system files: ^src\/.+py$|pyproject.toml|^tests\/.+py$ types_or: [python, toml] pass_filenames: false - id: tox docs name: tox-docs language: system entry: pdm run tox -e docs types_or: [python, rst, toml] files: ^src\/.+py$|pyproject.toml|^docs\/ pass_filenames: false - repo: https://github.com/pdm-project/pdm rev: 2.10.4 # a PDM release exposing the hook hooks: - id: pdm-lock-check - repo: https://github.com/jumanjihouse/pre-commit-hooks rev: 3.0.0 hooks: - id: markdownlint

Pre-commit hooks act as the first line of defense in maintaining code quality, seamlessly integrating with linters and code formatters. They automatically execute these tools each time a developer tries to commit code to the repository, ensuring the code adheres to the project's standards. If the hooks detect issues, the commit is paused until the issues are resolved, guaranteeing that only code meeting quality standards makes it into the repository.

Pre-commit Hooks: Pre-commit is a tool that can be set up to enforce coding rules and standards before you commit your changes to your code repository. This ensures that you can't even check in (commit) code that doesn't meet your standards. This allows a code reviewer to focus on the architecture of a change while not wasting time with trivial style nitpicks.

Ah, fair enough!

On my team we use pre-commit[0] a lot. I guess I would define the history to be something like "has this commit ever been run through our pre-commit hooks?". If you rewrite history, you'll (usually) produce commits that have not been through pre-commit (and they've therefore dodged a lot of static checks that might catch code that wasn't working, at that point in time). That gives some manner of objectivity to the "history", although it does depend on each user having their pre-commit hooks activated in their local workspace.

[0]: https://pre-commit.com/

Pre-commit is a framework for managing and maintaining multi-language pre-commit hooks. It supports hooks for various programming languages. Using this framework, you only have to specify a list of hooks you want to run before every commit, and pre-commit handles the installation and execution of those hooks despite your project’s primary language.

You can learn more here: pre-commit.com

Note this includes support for pre-commit.

As a nice next step, you could also add mypy to check your type hints are consistent, and automate running all this via pre-commit hooks set up with… pre-commit.