qontract-schemas

A repository containing schemas required for app-interface and qontract-reconcile.

Background

• Schema validation is based on json-schema.
• The custom validation engine is located at qcontract-validator.
• The schema data is located at app-interface

Local Development

To locally bundle and validate ONLY the schema you can run

make bundle-and-validate-schema

However, usually you want to validate a schema change against real existing data in app-interface. During the development process it is encouraged to rely on test data in app-sre/app-interface instead. See qcontract-server on how to bundle schema and app-interface data.

About the schemas definition

Crossrefs

Sub schema definitions and validations are made with the common-1.json/crossdef json definition. This section explains some considerations of this approach along with practical examples.

IMPORTANT: A crossref is not a common json schema cross reference, it just defines a string to point to the sub-schema definition file.

common-1.json

    "crossref": {
      "type": "object",
      "properties": {
        "$ref": {
          "type": "string",
          "format": "uri-reference"
        }
      },
      "required": [
        "$ref"
      ]

With this definition, a json validation will succeed if the $ref attribute of a crossref is a string with a uri-reference, but it won't validate that the schema of the destination file is the required one. Qontract-validator is used to validate the schemas and data within app-interface. crossrefs schemas validation is implemented with a $schemaRef attribute that should be placed in the attribute definition along with the crossref. e,g:

  aws_groups:
    type: array
    items:
      "$ref": "/common-1.json#/definitions/crossref"
      "$schemaRef": "/aws/group-1.yml"

With the $schemaRef attribute, qontract-validator is able to validate that the destination file matches the required schema. IMPORTANT $schemaRef can be a string pointing to a schema file or a inline fragment of a json schema definition. If it's a string, qontract-validator validates the destination file $schema attribute has the correct schema. If it's a json schema snippet, it validates the data with a json validator (Draft-06).

Examples:

Multiple allowed schemas for a crossref

What if we want to define a crossref with multiple allowed types? (datafiles case in role-1#self_service)

  datafiles:
    type: array
    items:
      "$ref": "/common-1.json#/definitions/crossref"
      "$schemaRef":
        type: object
        properties:
          '$schema':
            type: string
            enum:
              - "/app-sre/saas-file-2.yml"
              - "/openshift/namespace-1.yml"

datafiles:
- $ref: /services/test-saas-deployment-pipelines/cicd/deploy.yml
- $ref: /services/test-saas-deployment-pipelines/namespaces/stage.yml

With this definition, qontract-validator will validate that the $schema attribute of every entry in the list is defined within the enum.