CONTRACT_MONITORING.md

OpenAPI Specification (OAS) Contract Monitoring

An OAS/Swagger file can contain schemas under parameters and responses fields. With --contract catalogue.yaml CLI option, you can pass your API description to Mizu and the traffic will automatically be validated against the contracts.

Below is an example of an OAS/Swagger file from Sock Shop microservice demo that contains a bunch contracts:

openapi: 3.0.1
info:
  title: Catalogue resources
  version: 1.0.0
  description: ""
  license:
    name: MIT
    url: http://github.com/gruntjs/grunt/blob/master/LICENSE-MIT
paths:
  /catalogue:
    get:
      description: Catalogue API
      operationId: List catalogue
      responses:
        200:
          description: ""
          content:
            application/json;charset=UTF-8:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Listresponse'
  /catalogue/{id}:
    get:
      operationId: Get an item
      parameters:
      - name: id
        in: path
        required: true
        schema:
          type: string
        example: a0a4f044-b040-410d-8ead-4de0446aec7e
      responses:
        200:
          description: ""
          content:
            application/json; charset=UTF-8:
              schema:
                $ref: '#/components/schemas/Getanitemresponse'
  /catalogue/size:
    get:
      operationId: Get size
      responses:
        200:
          description: ""
          content:
            application/json;charset=UTF-8:
              schema:
                $ref: '#/components/schemas/Getsizeresponse'
  /tags:
    get:
      operationId: List_
      responses:
        200:
          description: ""
          content:
            application/json;charset=UTF-8:
              schema:
                $ref: '#/components/schemas/Listresponse3'
components:
  schemas:
    Listresponse:
      title: List response
      required:
      - count
      - description
      - id
      - imageUrl
      - name
      - price
      - tag
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        description:
          type: string
        imageUrl:
          type: array
          items:
            type: string
        price:
          type: number
          format: double
        count:
          type: integer
          format: int32
        tag:
          type: array
          items:
            type: string
    Getanitemresponse:
      title: Get an item response
      required:
      - count
      - description
      - id
      - imageUrl
      - name
      - price
      - tag
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        description:
          type: string
        imageUrl:
          type: array
          items:
            type: string
        price:
          type: number
          format: double
        count:
          type: integer
          format: int32
        tag:
          type: array
          items:
            type: string
    Getsizeresponse:
      title: Get size response
      required:
      - size
      type: object
      properties:
        size:
          type: integer
          format: int32
    Listresponse3:
      title: List response3
      required:
      - tags
      type: object
      properties:
        tags:
          type: array
          items:
            type: string

Pass it to Mizu through the CLI option: mizu tap -n sock-shop --contract catalogue.yaml

Now Mizu will monitor the traffic against these contracts.

If an entry fails to comply with the contract, it's marked with Breach notice in the UI. The reason of the failure can be seen under the CONTRACT tab in the details layout.

Notes

Make sure that you;

• specified the openapi version
• specified the info.version version in the YAML
• and removed servers field from the YAML

Otherwise the OAS file cannot be recognized. (see this issue)