Warning: This tool is not up-to-date with the current marathon version

A tiny command line tool to validate application or group configuration files for Marathon and DC/OS.

If you're running a Mesos or DC/OS cluster and build custom applications for if, most of the time you'll have to create either a Marathon app definition JSON file, or a group definition JSON file.

As the structure of these files can get a little complicated, marathon-validate was created to be able to do a quick sanity check of these files from the command line.

Therefore, marathon-validate will use the JSON schema files contained in the Marathon GitHub project to validate the input file against.

To be able to use marathon-validate, you need to have Node.js (and NPM) installed on your system. Then you can use

npm install -g marathon-validate

to install it globally. You can verify the correct installation by issuing

$ marathon-validate --version
0.3.3

$ marathon-validate --help

  Usage: marathon-validate [options] <file>

  Options:

    -h, --help                 output usage information
    -V, --version              output the version number
    -a, --app                  Check an App JSON
    -g, --group                Check a Group JSON
    -d, --describe <property>  Describe a property. Has to be used with either -a (app schema) or -g (group schema)
    -m, --marathon <version>   Use schema of specific Marathon version
    -t, --tags                 Get a list of tags for the Marathon project

If you want validate your application.json file in the current folder against the master version of the JSON schema, you can do a

$ marathon-validate -a application.json

To validate your application.json against a specific release version (e.g. v1.3.6), you can use

$ marathon-validate -a -m v1.3.6 application.json

This should work with all tags from the Marathon project.

You can also get the list of tags like this (output is shortened):

$ marathon-validate -t
--> List of tags:
     * v1.5.0-SNAPSHOT
     * v1.4.3
     * v1.4.2
     * v1.4.2-snapshot5
     * v1.4.2-snapshot4
     * v1.4.2-snapshot3
     * v1.4.2-snapshot2
     * v1.4.2-SNAPSHOT1
     * v1.4.1
     * v1.4.0
...

You can search the JSON schema for a field's description like this (in this example, the type field):

$ marathon-validate -a -d type
 --> Loading remote schema: https://raw.githubusercontent.com/mesosphere/marathon/master/docs/docs/rest-api/public/api/v2/schema/AppDefinition.json
 --> Found 2 matches for 'type':
     * '.container.type': Container engine type. Supported engine types at the moment are DOCKER and MESOS.
     * '.container.volumes.persistent.type': The type of mesos disk resource to use; defaults to root

By using the -a or -g flags, you can specify if you want to query the app or group JSON schema.