oam/knowledge base/yamllint.md

Yamllint

A linter for YAML files written in Python and compatible with Python 3 only.

TL;DR

# Use a specific configuration file.
yamllint -c /path/to/config file.yaml

# Pass custom configuration options on the CLI.
yamllint -d "{extends: relaxed, rules: {line-length: {max: 120}}}" file.yaml

Configuration

yamllint uses a set of rules to check YAML files for problems. Each rule is independent from the others, and can be enabled, disabled or tweaked. All these settings can be gathered in a configuration file.

To use a custom configuration file, use the -c option:

yamllint -c /path/to/config file.yaml

If no such option is provided, yamllint will look for a configuration file in the following locations (by order of preference):

• .yamllint, .yamllint.yaml or .yamllint.yml in the current working directory
• the file referenced by $YAMLLINT_CONFIG_FILE, if set
• $XDG_CONFIG_HOME/yamllint/config
• ~/.config/yamllint/config

Finally, if no config file is found the default configuration is applied.

You can avoid the need to redefine every rule when writing a custom configuration file extending the default one or any other already-existing configuration file:

extends: default
rules:
  comments-indentation: disable   # don't bother me at all with this rule

extends: relaxed
  line-length:   # just warn if a line is longer than 120 chars, instead of failing at 81
    max: 120
    level: warning
  indentation:   # loosen up on block sequences indentation
    indent-sequences: whatever

Further readings

• GitHub page
• Yamllint's documentation
• Rules