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. Joël Harkes reached a similar conclusion to the approach I ended up taking.
Building the schemas yourself
The tooling for generating these schemas is openapi2jsonschema. It's not Kubernetes specific and should work with other OpenAPI specificied APIs too.