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jobs.deployment.strategy.rolling definition

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A rolling deployment replaces instances of the previous version of an application with instances of the new version of the application on a fixed set of virtual machines (rolling set) in each iteration.

rolling:
  maxParallel: string # Maximum number of jobs running in parallel.
  preDeploy: # Pre deploy hook for rolling deployment strategy.
    steps: [ task | script | powershell | pwsh | bash | checkout | download | downloadBuild | getPackage | publish | template | reviewApp ] # A list of steps to run.
    pool: string | pool # Pool where pre deploy steps will run.
  deploy: # Deploy hook for rolling deployment strategy.
    steps: [ task | script | powershell | pwsh | bash | checkout | download | downloadBuild | getPackage | publish | template | reviewApp ] # A list of steps to run.
    pool: string | pool # Pool where deploy steps will run.
  routeTraffic: # Route traffic hook for rolling deployment strategy.
    steps: [ task | script | powershell | pwsh | bash | checkout | download | downloadBuild | getPackage | publish | template | reviewApp ] # A list of steps to run.
    pool: string | pool # Pool where route traffic steps will run.
  postRouteTraffic: # Post route traffic hook for rolling deployment strategy.
    steps: [ task | script | powershell | pwsh | bash | checkout | download | downloadBuild | getPackage | publish | template | reviewApp ] # A list of steps to run.
    pool: string | pool # Pool where post route traffic steps will run.
  on: # On success or failure hook for rolling deployment strategy.
    failure: # Runs on failure of any step.
      steps: [ task | script | powershell | pwsh | bash | checkout | download | downloadBuild | getPackage | publish | template | reviewApp ] # A list of steps to run.
      pool: string | pool # Pool where post on failure steps will run.
    success: # Runs on success of all of the steps.
      steps: [ task | script | powershell | pwsh | bash | checkout | download | downloadBuild | getPackage | publish | template | reviewApp ] # A list of steps to run.
      pool: string | pool # Pool where on success steps will run.

Definitions that reference this definition: jobs.deployment.strategy

Properties

maxParallel string.
Maximum number of jobs running in parallel.

preDeploy preDeployHook.
Pre deploy hook for rolling deployment strategy.

deploy deployHook.
Deploy hook for rolling deployment strategy.

routeTraffic routeTrafficHook.
Route traffic hook for rolling deployment strategy.

postRouteTraffic postRouteTrafficHook.
Post route traffic hook for rolling deployment strategy.

on onSuccessOrFailureHook.
On success or failure hook for rolling deployment strategy.

Remarks

Azure Pipelines currently only support the rolling strategy to VM resources.

For example, a rolling deployment typically waits for deployments on each set of virtual machines to complete before proceeding to the next set of deployments. You could do a health check after each iteration and if a significant issue occurs, the rolling deployment can be stopped.

Rolling deployments can be configured by specifying the keyword rolling: under the strategy: node. The strategy.name variable is available in this strategy block, which takes the name of the strategy. In this case, rolling.

All the lifecycle hooks are supported and lifecycle hook jobs are created to run on each VM.

preDeploy, deploy, routeTraffic, and postRouteTraffic are executed once per batch size defined by maxParallel. Then, either on: success or on: failure is executed.

With maxParallel: <# or % of VMs>, you can control the number/percentage of virtual machine targets to deploy to in parallel. This ensures that the app is running on these machines and is capable of handling requests while the deployment is taking place on the rest of the machines, which reduces overall downtime.

Note

There are a few known gaps in this feature. For example, when you retry a stage, it will re-run the deployment on all VMs not just failed targets.

Descriptions of lifecycle hooks

preDeploy: Used to run steps that initialize resources before application deployment starts.

deploy: Used to run steps that deploy your application. Download artifact task will be auto injected only in the deploy hook for deployment jobs. To stop downloading artifacts, use - download: none or choose specific artifacts to download by specifying Download Pipeline Artifact task.

routeTraffic: Used to run steps that serve the traffic to the updated version.

postRouteTraffic: Used to run the steps after the traffic is routed. Typically, these tasks monitor the health of the updated version for defined interval.

on: failure or on: success: Used to run steps for rollback actions or clean-up.

Examples

The following rolling strategy example for VMs updates up to five targets in each iteration. maxParallel will determine the number of targets that can be deployed to, in parallel. The selection accounts for absolute number or percentage of targets that must remain available at any time excluding the targets that are being deployed to. It is also used to determine the success and failure conditions during deployment.

jobs: 
- deployment: VMDeploy
  displayName: web
  environment:
    name: smarthotel-dev
    resourceType: VirtualMachine
  strategy:
    rolling:
      maxParallel: 5  #for percentages, mention as x%
      preDeploy:
        steps:
        - download: current
          artifact: drop
        - script: echo initialize, cleanup, backup, install certs
      deploy:
        steps:
        - task: IISWebAppDeploymentOnMachineGroup@0
          displayName: 'Deploy application to Website'
          inputs:
            WebSiteName: 'Default Web Site'
            Package: '$(Pipeline.Workspace)/drop/**/*.zip'
      routeTraffic:
        steps:
        - script: echo routing traffic
      postRouteTraffic:
        steps:
        - script: echo health check post-route traffic
      on:
        failure:
          steps:
          - script: echo Restore from backup! This is on failure
        success:
          steps:
          - script: echo Notify! This is on success

See also