OpenShift JSON Schemas

For the upstream Kubernetes schemas instead see garethr/kubernetes-json-schema.

While exploring tooling for Kubernetes I had need for schemas to describe the definition files, and went looking for something that didn't require either kubectl or similar installed or even a working Kubernetes installation.

It turns out that the OpenAPI specification contain this information, but not in a particularly usable format for tools which might just want a raw JSON Schema.

This repository contains a set of schemas for most recent OpenShift versions. For each specified versions you should find three different flavours:

vX.Y.Z - URL referenced based on the specified GitHub repository
vX.Y.Z-standalone - de-referenced schemas, more useful as standalone documents
vX.Y.Z-local - relative references, useful to avoid the network dependency

Example

Here are the links to the latest deployment schemas for OpenShift 1.5.1:

Usage

There are lots of use cases for these schemas, they are primarily useful as a low-level part of other developer workflow tools. But at a most basic level you can validate a definition file.

Here is a very simply example using the Python jsonschema client and an invalid deployment file:

$ jsonschema -F "{error.message}" -i hello-nginx.json 1.5.1-standalone/deployment.json
u'template' is a required property

Specific ideas

As noted these schemas have lots of potential uses for development tools. Here are a few ideas, some of which I've been hacking on:

Demonstrating using with the more common YAML serialisation
Testing tools to show your Kubernetes configuration files are valid,
and against which versions of Kubernetes
Migration tools to check your config files are still valid against
master or beta releases
Integration with code editors, for instance via something like Schema
Store
Validation of Kubernetes configs generated by higher-level tools, like
Helm, Ksonnet or Puppet
Visual tools for crafting Kubernetes configurations
Tools to show changes between Kubernetes versions

Prior-art

The discussion around wanting JSON Schemas for Kubernetes types has cropped up in a few places, but there are some useful comments on this issue. Jol Harkes reached a similar conclusion to the approach I ended up taking.