yamllint ( YAML Linter)

The `yamllint` is basically a program to check syntax of YAML files. If you got YAML files in your project, you can ask your CI (continuous integration) to check for YAML syntax.

Read yamllint documentation at https://yamllint.readthedocs.io/en/latest/index.html

What is yamllint?

A linter for YAML files

What is Linting?

Linting is the process of running a program that will analyse code for potential errors.

A simple way to install it

pip install yamllint

A simple usage

yamllint .

Output:

./my1.yml

  1:1       warning  missing document start "---"  (document-start)

  19:7      error    wrong indentation: expected 8 but found 6  (indentation)

  22:9      error    wrong indentation: expected 10 but found 8  (indentation)

  35:9      error    wrong indentation: expected 10 but found 8  (indentation)

  40:81     error    line too long (86 > 80 characters)  (line-length)

  46:9      error    wrong indentation: expected 10 but found 8  (indentation)

  49:7      error    wrong indentation: expected 8 but found 6  (indentation)

./my2.yml

  1:1       warning  missing document start "---"  (document-start)

  6:7       error    wrong indentation: expected 4 but found 6  (indentation)

  9:5       error    wrong indentation: expected 2 but found 4  (indentation)

  11:5      error    wrong indentation: expected 6 but found 4  (indentation)

It recursively checks all the yaml files in the current directory

Can we guide yamllint what to check in configuration file?

Create a config file

cat .yamllint.yaml

extends: default

rules:

  # 90 chars should be enough, but don't fail if a line is longer

  line-length:

    max: 90

    level: warning

  # Disabling the document-start error messages

  document-start:

    present: false

yamllint -c .yamllint.yaml .