Amazon Fargate Roll Out a Service Update

arazzo: 1.0.1
info:
  title: Amazon Fargate Roll Out a Service Update
  summary: Register a new task definition revision, update a service to it, and poll until the deployment is steady.
  description: >-
    A rolling deployment for an existing Fargate service. The workflow registers
    a new revision of the task definition (typically a new image), updates the
    target service to that revision and an optional new desired count, and then
    polls DescribeServices until the running count matches the desired count.
    Each step inlines its AWS JSON 1.1 request and the X-Amz-Target action
    header so the rollout can be read and executed directly.
  version: 1.0.0
sourceDescriptions:
- name: fargateApi
  url: ../openapi/amazon-fargate-openapi.yml
  type: openapi
workflows:
- workflowId: rolling-update-service
  summary: Register a new task definition revision and roll it out to an existing service.
  description: >-
    Chains registerTaskDefinition and updateService, then loops over
    describeServices until the new deployment reaches steady state.
  inputs:
    type: object
    required:
    - cluster
    - service
    - family
    - containerName
    - image
    properties:
      cluster:
        type: string
        description: Name or ARN of the cluster hosting the service.
      service:
        type: string
        description: Name or ARN of the service to update.
      family:
        type: string
        description: Family name for the new task definition revision.
      containerName:
        type: string
        description: Name of the container in the task definition.
      image:
        type: string
        description: New container image URI to deploy.
      cpu:
        type: string
        description: Task-level CPU units for Fargate.
        default: "256"
      memory:
        type: string
        description: Task-level memory in MiB for Fargate.
        default: "512"
      executionRoleArn:
        type: string
        description: ARN of the ECS task execution role.
      desiredCount:
        type: integer
        description: Desired number of tasks after the update.
  steps:
  - stepId: registerNewRevision
    description: Register a new revision of the task definition with the updated image.
    operationId: registerTaskDefinition
    parameters:
    - name: X-Amz-Target
      in: header
      value: AmazonEC2ContainerServiceV20141113.RegisterTaskDefinition
    requestBody:
      contentType: application/x-amz-json-1.1
      payload:
        family: $inputs.family
        requiresCompatibilities:
        - FARGATE
        networkMode: awsvpc
        cpu: $inputs.cpu
        memory: $inputs.memory
        executionRoleArn: $inputs.executionRoleArn
        containerDefinitions:
        - name: $inputs.containerName
          image: $inputs.image
          essential: true
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      taskDefinitionArn: $response.body#/taskDefinition/taskDefinitionArn
      revision: $response.body#/taskDefinition/revision
  - stepId: updateService
    description: Update the service to the new task definition revision and desired count.
    operationId: updateService
    parameters:
    - name: X-Amz-Target
      in: header
      value: AmazonEC2ContainerServiceV20141113.UpdateService
    requestBody:
      contentType: application/x-amz-json-1.1
      payload:
        cluster: $inputs.cluster
        service: $inputs.service
        taskDefinition: $steps.registerNewRevision.outputs.taskDefinitionArn
        desiredCount: $inputs.desiredCount
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      serviceArn: $response.body#/service/serviceArn
      desiredCount: $response.body#/service/desiredCount
  - stepId: pollDeployment
    description: >-
      Poll DescribeServices until the running count matches the desired count,
      re-entering while the rollout is still in progress.
    operationId: describeServices
    parameters:
    - name: X-Amz-Target
      in: header
      value: AmazonEC2ContainerServiceV20141113.DescribeServices
    requestBody:
      contentType: application/x-amz-json-1.1
      payload:
        cluster: $inputs.cluster
        services:
        - $inputs.service
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      runningCount: $response.body#/services/0/runningCount
      desiredCount: $response.body#/services/0/desiredCount
      status: $response.body#/services/0/status
    onSuccess:
    - name: rollingOut
      type: goto
      stepId: pollDeployment
      criteria:
      - context: $response.body
        condition: $.services[0].runningCount != $.services[0].desiredCount
        type: jsonpath
    - name: deployed
      type: end
      criteria:
      - context: $response.body
        condition: $.services[0].runningCount == $.services[0].desiredCount
        type: jsonpath
  outputs:
    taskDefinitionArn: $steps.registerNewRevision.outputs.taskDefinitionArn
    serviceArn: $steps.updateService.outputs.serviceArn
    runningCount: $steps.pollDeployment.outputs.runningCount