openapi: 3.0.0
info:
  title: Application Metric API
  description: |
    List aggregated metrics of an application. AutoScaler collects the instances metrics of an
    application, and aggregate the raw data into an accumulated value for evaluation.

    This API is used to return the aggregated metric result of an application.
  version: 1.0.0
  license:
    name: "Apache License Version 2.0"
    # identifier: "Apache-2.0" # Requires at least OpenAPI 3.1.0
    url: "http://www.apache.org/licenses/LICENSE-2.0.html"
tags:
- name: Application Metric API V1
  description: List aggregated metrics of an application.

paths:
  /v1/apps/{guid}/aggregated_metric_histories/{metric_type}:
    parameters:
    - name: guid
      in: path
      required: true
      description: |
        The GUID identifying the application for which the aggregated metric histories is fetched.

        It can be found in the `application_id` property of the JSON object stored in the
        `VCAP_APPLICATION` environment variable.
      schema:
       $ref: "./shared_definitions.yaml#/schemas/GUID"
    - name: metric_type
      in: path
      required: true
      description: The metric type
      schema:
        $ref: "./shared_definitions.yaml#/schemas/metric_type"
    - name: start-time
      in: query
      description: |
        The start time in the number of nanoseconds elapsed since January 1, 1970 UTC.
      schema:
        type: integer
        default: 0
      example: start-time=1494989539138350432
    - name: end-time
      in: query
      description: |
        The end time in the number of nanoseconds elapsed since January 1, 1970 UTC.
      schema:
        type: integer
        default: 0
      example: end-time=1494989549117047288
    - name: order-direction
      in: query
      description: |
        The sorting order. The scaling history will be order by timestamp ascending or descending.
      schema:
        type: string
        enum: ["asc", "desc"]
        default: desc
      example: order-direction=desc
    - name: page
      in: query
      description: The page number to query.
      schema:
        type: integer
        minimum: 1 # Or Should it be "1"?
        default: 1
        example: page=1
    - name: results-per-page
      in: query
      description: Number of entries shown per page.
      schema:
        type: integer
        minimum: 0 # Or Should it be "1"?
        default: 50
      example: results-per-page=10
    get:
      summary: Retrieves the instance metrics of an application.
      description: |
         Use to retrieve instance metrics of an application.
      tags:
      - Application Metric API V1
      responses:
        "200":
         description: "OK"
         content:
          application/json:
           schema:
             $ref: "#/components/schemas/Application_Metrics"
        default:
           $ref: "./shared_definitions.yaml#/responses/Error"
      security:
      - bearerAuth: []
      x-codegen-request-body-name: body
components:
  schemas:
    Application_Metrics:
      description: Object containing Application Metrics
      type: object
      properties:
        total_results:
          type: integer
          format: int64
          description: Number of history entries found for the given query
          example: 2
        total_pages:
          type: integer
          format: int64
          description: Number of Pages from the query
          example: 1
        page:
          type: integer
          format: int64
          description: Number of the current page
          example: 1
        prev_url:
          type: string
          format: uri
        next_url:
          type: string
          format: uri
        resources:
          type: array
          items:
            $ref: '#/components/schemas/ApplicationMetric'
    ApplicationMetric:
      description: Object containing metric history
      type: object
      properties:
        app_guid:
          $ref: "./shared_definitions.yaml#/schemas/GUID"
        instanceIndex:
          type: integer
          description: Application Metric #TODO
          example: 0
        timestamp:
          type: integer
          description: |
            The scaling time in the number of nanoseconds elapsed since January 1, 1970 UTC.
          example: 1494989539138350432
        collected_at:
          type: integer
          description: |
            The time at which the metrics were collected in the number of nanoseconds
          example: 1494989539138350000
        metric_type:
          $ref: "./shared_definitions.yaml#/schemas/metric_type"
        value:
          type: integer
          description: |
            The value of metric type to be returned as the aggregated metric result of an application
          example: 400
        unit:
          type: string
          example: megabytes
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT