YAML Schema Validation?

Is there a schema validation language for YAML? I've googled but couldn't find anything useful.

Something like XSD format, using the language itself to describe the schema, would be the best choice in my case.

Solution 1:

JSON Schema can be used with most YAML documents resulting in a more portable and better documented solution than Rx or Kwalify. JSON Schema is the only of the three for which I have been able to find editor support.

More information on using YAML and JSON Schema including tools and editor support is tracked on this page. At the time of writing, there is editor support in Visual Studio Code and a command-line based validation tool available via npm.

Full Disclosure: I authored the web site linked above to try to make the application of JSON Schema to YAML more discoverable. I also wrote an editor extension for VS Code that has since been superseded by the RedHat extension linked above.

Solution 2:

Try Kwalify (Ruby and Java only), or Rx (many languages)

Solution 3:

I wonder if it would make sense to reuse JSON schema for this. YAML can be easily converted to JSON without loosing any information (?), so in theory YAML could be validated by the same tool chain, allowing open source community to concentrate on one good schema tool chain. The schema itself could also be written in YAML and converted to JSON.