Super-Linter

This repository is for the GitHub Action to run a Super-Linter. It is a simple combination of various linters, written in bash, to help validate your source code.

The end goal of this tool:

• Prevent broken code from being uploaded to the default branch (Usually master)
• Help establish coding best practices across multiple languages
• Build guidelines for code layout and format
• Automate the process to help streamline code reviews

Table of Contents

• How it works
• Supported linters
• Usage
• Environment variables
• Disable rules
• Docker Hub
• Run Super-Linter locally
  • CI / CT/ CD
• Limitations
• Contributing

How it Works

The super-linter finds issues and reports them to the console output. Fixes are suggested in the console output but not automatically fixed, and a status check will show up as failed on the pull request.

The design of the Super-Linter is currently to allow linting to occur in GitHub Actions as a part of continuous integration occurring on pull requests as the commits get pushed. It works best when commits are being pushed early and often to a branch with an open or draft pull request. There is some desire to move this closer to local development for faster feedback on linting errors but this is not yet supported.

Supported Linters

Developers on GitHub can call the GitHub Action to lint their code base with the following list of linters:

Language	Linter
Ansible	ansible-lint
AWS CloudFormation templates	cfn-lint
CSS	stylelint
Clojure	clj-kondo
CoffeeScript	coffeelint
Dockerfile	dockerfilelint
ENV	dotenv-linter
Golang	golangci-lint
JavaScript	eslint standard js
JSON	jsonlint
Kotlin	ktlint
Markdown	markdownlint
OpenAPI	spectral
Perl	perl
PHP	PHP
PowerShell	PSScriptAnalyzer
Protocol Buffers	protolint
Python3	pylint
Ruby	RuboCop
Shell	Shellcheck
Terraform	tflint
TypeScript	eslint standard js
XML	LibXML
YAML	YamlLint

How to use

More in-depth tutorial available

To use this GitHub Action you will need to complete the following:

1. Create a new file in your repository called .github/workflows/linter.yml
2. Copy the example workflow from below into that new file, no extra configuration required
3. Commit that file to a new branch
4. Open up a pull request and observe the action working
5. Enjoy your more stable, and cleaner code base
6. Check out the Wiki for customization options

Example connecting GitHub Action Workflow

In your repository you should have a .github/workflows folder with GitHub Action similar to below:

• .github/workflows/linter.yml

This file should have the following code:

---
###########################
###########################
## Linter GitHub Actions ##
###########################
###########################
name: Lint Code Base

#
# Documentation:
# https://help.github.com/en/articles/workflow-syntax-for-github-actions
#

#############################
# Start the job on all push #
#############################
on:
  push:
    branches-ignore: [master]
    # Remove the line above to run when pushing to master
  pull_request:
    branches: [master]

###############
# Set the Job #
###############
jobs:
  build:
    # Name the Job
    name: Lint Code Base
    # Set the agent to run on
    runs-on: ubuntu-latest

    ##################
    # Load all steps #
    ##################
    steps:
      ##########################
      # Checkout the code base #
      ##########################
      - name: Checkout Code
        uses: actions/checkout@v2

      ################################
      # Run Linter against code base #
      ################################
      - name: Lint Code Base
        uses: docker://github/super-linter:v3
        env:
          VALIDATE_ALL_CODEBASE: false
          DEFAULT_BRANCH: master

...

NOTE:
Using the line:uses: docker://github/super-linter:v3 will pull the image down from DockerHub and run the GitHub Super-Linter. Using the line: uses: github/super-linter@v3 will build and compile the GitHub Super-Linter at build time. This can be far more costly in time...

Environment variables

The super-linter allows you to pass the following ENV variables to be able to trigger different functionality.

Note: All the VALIDATE_[LANGUAGE] variables behave in a specific way. If none of them are passed, then they all default to true. However if any one of the variables are set, we default to leaving any unset variable to false. This means that if you run the linter "out of the box", all languages will be checked. But if you wish to select specific linters, we give you full control to choose which linters are run, and won't run anything unexpected.

ENV VAR	Default Value	Notes
VALIDATE_ALL_CODEBASE	true	Will parse the entire repository and find all files to validate across all types. NOTE: When set to false, only new or edited files will be parsed for validation.
DEFAULT_BRANCH	master	The name of the repository default branch.
LINTER_RULES_PATH	.github/linters	Directory for all linter configuration rules.
VALIDATE_YAML	true	Flag to enable or disable the linting process of the language.
VALIDATE_JSON	true	Flag to enable or disable the linting process of the language.
VALIDATE_XML	true	Flag to enable or disable the linting process of the language.
VALIDATE_MD	true	Flag to enable or disable the linting process of the language.
VALIDATE_BASH	true	Flag to enable or disable the linting process of the language.
VALIDATE_PERL	true	Flag to enable or disable the linting process of the language.
VALIDATE_PHP	true	Flag to enable or disable the linting process of the language.
VALIDATE_PYTHON	true	Flag to enable or disable the linting process of the language.
VALIDATE_RUBY	true	Flag to enable or disable the linting process of the language.
RUBY_CONFIG_FILE	.ruby-lint.yml	Filename for rubocop configuration (ex: .ruby-lint.yml, .rubocop.yml)
VALIDATE_COFFEE	true	Flag to enable or disable the linting process of the language .
VALIDATE_ANSIBLE	true	Flag to enable or disable the linting process of the language.
VALIDATE_JAVASCRIPT_ES	true	Flag to enable or disable the linting process of the language. (Utilizing: eslint)
JAVASCRIPT_ES_CONFIG_FILE	.eslintrc.yml	Filename for eslint configuration (ex: .eslintrc.yml, .eslintrc.json)
VALIDATE_JAVASCRIPT_STANDARD	true	Flag to enable or disable the linting process of the language. (Utilizing: standard)
VALIDATE_TYPESCRIPT_ES	true	Flag to enable or disable the linting process of the language. (Utilizing: eslint)
TYPESCRIPT_ES_CONFIG_FILE	.eslintrc.yml	Filename for eslint configuration (ex: .eslintrc.yml, .eslintrc.json)
VALIDATE_TYPESCRIPT_STANDARD	true	Flag to enable or disable the linting process of the language. (Utilizing: standard)
VALIDATE_DOCKER	true	Flag to enable or disable the linting process of the language.
VALIDATE_GO	true	Flag to enable or disable the linting process of the language.
VALIDATE_POWERSHELL	true	Flag to enable or disable the linting process of the language.
VALIDATE_TERRAFORM	true	Flag to enable or disable the linting process of the language.
VALIDATE_CSS	true	Flag to enable or disable the linting process of the language.
VALIDATE_ENV	true	Flag to enable or disable the linting process of the language.
VALIDATE_CLOJURE	true	Flag to enable or disable the linting process of the language.
VALIDATE_KOTLIN	true	Flag to enable or disable the linting process of the language.
VALIDATE_OPENAPI	true	Flag to enable or disable the linting process of the language.
VALIDATE_CLOUDFORMATION	true	Flag to enable or disable the linting process of the language.
VALIDATE_PROTOBUF	true	Flag to enable or disable the linting process of the language.
ANSIBLE_DIRECTORY	/ansible	Flag to set the root directory for Ansible file location(s).
ACTIONS_RUNNER_DEBUG	false	Flag to enable additional information about the linter, versions, and additional output.
DISABLE_ERRORS	false	Flag to have the linter complete with exit code 0 even if errors were detected.
DEFAULT_WORKSPACE	/tmp/lint	The location containing files to lint if you are running locally.

Template rules files

You can use the GitHub Super-Linter with or without your own personal rules sets. This allows for greater flexibility for each individual code base. The Template rules all try to follow the standards we believe should be enabled at the basic level.

• Copy any or all template rules files from TEMPLATES/ into your repository in the location: .github/linters/ of your repository
  • If your repository does not have rules files, they will fall back to defaults in this repository's TEMPLATE folder

Disabling rules

If you need to disable certain rules and functionality, you can view Disable Rules

Docker Hub

The Docker container that is built from this repository is located at https://hub.docker.com/r/github/super-linter

Running Super-Linter locally (troubleshooting/debugging/enhancements)

If you find that you need to run super-linter locally, you can follow the documentation at Running super-linter locally

Check out the note in How it Works to understand more about the Super-Linter linting locally versus via continuous integration.

CI/CT/CD

The Super-Linter has CI/CT/CD configured utilizing GitHub Actions.

• When a branch is created and code is pushed, a GitHub Action is triggered for building the new Docker container with the new codebase
• The Docker container is then ran against the test cases to validate all code sanity
  • .automation/test contains all test cases for each language that should be validated
• These GitHub Actions utilize the Checks API and Protected Branches to help follow the SDLC
• When the Pull Request is merged to master, the Super-Linter Docker container is then updated and deployed with the new codebase
  • Note: The branch's Docker container is also removed from DockerHub to cleanup after itself

Limitations

Below are a list of the known limitations for the GitHub Super-Linter:

• Due to being completely packaged at run time, you will not be able to update dependencies or change versions of the enclosed linters and binaries
• Additional details from package.json are not read by the GitHub Super-Linter
• Downloading additional codebases as dependencies from private repositories will fail due to lack of permissions

How to contribute

If you would like to help contribute to this GitHub Action, please see CONTRIBUTING

Visual Studio Code

You can checkout this repository using Container Remote Development, and debug the linter using the Test Linter task.

We will also support Github Codespaces once it becomes available

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License

• MIT License