actionlint

Static checker for GitHub Actions workflow files

actionlint documentation

Version in MegaLinter: 1.6.24
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See How to configure actionlint rules

Configuration in MegaLinter

Enable actionlint by adding ACTION_ACTIONLINT in ENABLE_LINTERS variable
Disable actionlint by adding ACTION_ACTIONLINT in DISABLE_LINTERS variable

Variable	Description	Default value
ACTION_ACTIONLINT_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
ACTION_ACTIONLINT_FILTER_REGEX_INCLUDE	Custom regex including filter Ex: `(src\\|lib)`	Include every file
ACTION_ACTIONLINT_FILTER_REGEX_EXCLUDE	Custom regex excluding filter Ex: `(test\\|examples)`	Exclude no file
ACTION_ACTIONLINT_CLI_LINT_MODE	Override default CLI lint mode - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`list_of_files`
ACTION_ACTIONLINT_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".yml", ".yaml"]`
ACTION_ACTIONLINT_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
ACTION_ACTIONLINT_PRE_COMMANDS	List of bash commands to run before the linter	None
ACTION_ACTIONLINT_POST_COMMANDS	List of bash commands to run after the linter	None
ACTION_ACTIONLINT_UNSECURED_ENV_VARIABLES	List of env variables explicitly not filtered before calling ACTION_ACTIONLINT and its pre/post commands	None
ACTION_ACTIONLINT_CONFIG_FILE	actionlint configuration file nameUse `LINTER_DEFAULT` to let the linter find it	`actionlint.yml`
ACTION_ACTIONLINT_RULES_PATH	Path where to find linter configuration file	Workspace folder, then MegaLinter default rules
ACTION_ACTIONLINT_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
ACTION_ACTIONLINT_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`
ACTION_ACTIONLINT_CLI_EXECUTABLE	Override CLI executable	`['actionlint']`
ACTION_DIRECTORY	Directory containing ACTION files	`.github/workflows`

MegaLinter Flavours

This linter is available in the following flavours

Flavor	Description	Embedded linters
all	Default MegaLinter Flavor	113
cupcake	MegaLinter for the most commonly used languages	81
documentation	MegaLinter for documentation projects	47
dotnet	Optimized for C, C++, C# or VB based projects	59
go	Optimized for GO based projects	49
java	Optimized for JAVA based projects	51
javascript	Optimized for JAVASCRIPT or TYPESCRIPT based projects	56
php	Optimized for PHP based projects	50
python	Optimized for PYTHON based projects	58
ruby	Optimized for RUBY based projects	47
rust	Optimized for RUST based projects	47
salesforce	Optimized for Salesforce based projects	50
swift	Optimized for SWIFT based projects	47
terraform	Optimized for TERRAFORM based projects	51

Behind the scenes

How are identified applicable files

Activated only if sub-directory .github/workflows is found. (directory name can be overridden with ACTION_DIRECTORY)
File extensions: .yml, .yaml

How the linting is performed

actionlint is called once with the list of files as arguments (list_of_files CLI lint mode)

Example calls

actionlint /path/to/workflow1.yml /path/to/workflow2.yaml

Help content

Usage: actionlint [FLAGS] [FILES...] [-]

  actionlint is a linter for GitHub Actions workflow files.

  To check all YAML files in current repository, just run actionlint without
  arguments. It automatically finds the nearest '.github/workflows' directory:

    $ actionlint

  To check specific files, pass the file paths as arguments:

    $ actionlint file1.yaml file2.yaml

  To check content which is not saved in file yet (e.g. output from some
  command), pass - argument. It reads stdin and checks it as workflow file:

    $ actionlint -

  To serialize errors into JSON, use -format option. It allows to format error
  messages flexibly with Go template syntax.

    $ actionlint -format '{{json .}}'

Documents:

  https://github.com/rhysd/actionlint/tree/main/docs

Flags:
  -color
      Always enable colorful output. This is useful to force colorful outputs
  -config-file string
      File path to config file
  -debug
      Enable debug output (for development)
  -format string
      Custom template to format error messages in Go template syntax. See https://github.com/rhysd/actionlint/tree/main/docs/usage.md#format
  -ignore value
      Regular expression matching to error messages you want to ignore. This flag is repeatable
  -init-config
      Generate default config file at .github/actionlint.yaml in current project
  -no-color
      Disable colorful output
  -oneline
      Use one line per one error. Useful for reading error messages from programs
  -pyflakes string
      Command name or file path of "pyflakes" external command. If empty, pyflakes integration will be disabled (default "pyflakes")
  -shellcheck string
      Command name or file path of "shellcheck" external command. If empty, shellcheck integration will be disabled (default "shellcheck")
  -stdin-filename string
      File name when reading input from stdin
  -verbose
      Enable verbose output
  -version
      Show version and how this binary was installed

Installation on mega-linter Docker image

Dockerfile commands :

FROM rhysd/actionlint:latest as actionlint
# shellcheck is a dependency for actionlint

FROM koalaman/shellcheck:stable as shellcheck
COPY --link --from=actionlint /usr/local/bin/actionlint /usr/bin/actionlint
# shellcheck is a dependency for actionlint

COPY --link --from=shellcheck /bin/shellcheck /usr/bin/shellcheck

APK packages (Linux):
- py3-pyflakes