Jenkins Instance Health and Capacity Check

arazzo: 1.0.1
info:
  title: Jenkins Instance Health and Capacity Check
  summary: Read instance mode and executor count, check agents are online, and measure queue depth.
  description: >-
    The monitoring flow an operator or a scheduled check runs against a Jenkins
    controller. The workflow reads the top-level instance resource for its mode,
    quieting-down state, and executor count, lists the connected agents to see
    how many are offline or temporarily offline, and then reads the build queue
    to measure how much work is waiting. Together these three reads answer
    whether the instance can currently accept and run builds. Every step spells
    out its request inline so the flow can be read and executed without opening
    the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: jenkinsApi
  url: ../openapi/jenkins-openapi.yml
  type: openapi
workflows:
- workflowId: instance-health-check
  summary: Check that a Jenkins controller is accepting work and has executor capacity.
  description: >-
    Reads the controller's mode and executor count, inspects the connected
    agents for offline state, and reads the queue depth. A controller that is
    quieting down, has every agent offline, or has a deep queue cannot be
    relied on to run a build promptly.
  inputs:
    type: object
    properties:
      depth:
        type: integer
        description: >-
          Optional depth for expanding nested objects in the agent listing.
          Defaults are usually sufficient; raise only when more detail is needed.
  steps:
  - stepId: readInstance
    description: >-
      Read the top-level Jenkins resource for its mode, whether it is quieting
      down ahead of a restart, and how many executors it advertises.
    operationId: getJenkinsInfo
    parameters:
    - name: tree
      in: query
      value: mode,nodeName,nodeDescription,numExecutors,quietingDown,useSecurity
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.quietingDown == false
      type: jsonpath
    outputs:
      mode: $response.body#/mode
      numExecutors: $response.body#/numExecutors
      quietingDown: $response.body#/quietingDown
  - stepId: checkAgents
    description: >-
      List the connected build agents and their offline state, so a controller
      with no usable executors is caught before builds are queued against it.
    operationId: listComputers
    parameters:
    - name: depth
      in: query
      value: $inputs.depth
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      computers: $response.body#/computer
      busyExecutors: $response.body#/busyExecutors
      totalExecutors: $response.body#/totalExecutors
  - stepId: measureQueue
    description: >-
      Read the build queue to measure how many items are waiting and why, which
      distinguishes a saturated instance from a blocked one.
    operationId: getQueue
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      queueItems: $response.body#/items
  outputs:
    mode: $steps.readInstance.outputs.mode
    quietingDown: $steps.readInstance.outputs.quietingDown
    busyExecutors: $steps.checkAgents.outputs.busyExecutors
    totalExecutors: $steps.checkAgents.outputs.totalExecutors
    queueItems: $steps.measureQueue.outputs.queueItems