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jobs.deployment.strategy.canary definition

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Canary deployment strategy rolls out changes to a small subset of servers.

canary:
  increments: [ string ] # Maximum batch size for deployment.
  preDeploy: # Pre deploy hook for canary 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 canary 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 canary 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 canary 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 canary 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

increments string list.
Maximum batch size for deployment.

preDeploy preDeployHook.
Pre deploy hook for canary deployment strategy.

deploy deployHook.
Deploy hook for canary deployment strategy.

routeTraffic routeTrafficHook.
Route traffic hook for canary deployment strategy.

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

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

Remarks

Canary deployment strategy is an advanced deployment strategy that helps mitigate the risk involved in rolling out new versions of applications. By using this strategy, you can roll out the changes to a small subset of servers first. As you gain more confidence in the new version, you can release it to more servers in your infrastructure and route more traffic to it.

Canary deployment strategy supports the preDeploy lifecycle hook (executed once) and iterates with the deploy, routeTraffic, and postRouteTraffic lifecycle hooks. It then exits with either the success or failure hook.

The following variables are available in this strategy:

strategy.name: Name of the strategy. For example, canary.
strategy.action: The action to be performed on the Kubernetes cluster. For example, deploy, promote, or reject.
strategy.increment: The increment value used in the current interaction. This variable is available only in deploy, routeTraffic, and postRouteTraffic lifecycle hooks.

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

In the following example, the canary strategy for AKS will first deploy the changes with 10 percent pods, followed by 20 percent, while monitoring the health during postRouteTraffic. If all goes well, it will promote to 100 percent.

jobs: 
- deployment: 
  environment: smarthotel-dev.bookings
  pool: 
    name: smarthotel-devPool
  strategy:                  
    canary:      
      increments: [10,20]  
      preDeploy:                                     
        steps:           
        - script: initialize, cleanup....   
      deploy:             
        steps: 
        - script: echo deploy updates... 
        - task: KubernetesManifest@0 
          inputs: 
            action: $(strategy.action)       
            namespace: 'default' 
            strategy: $(strategy.name) 
            percentage: $(strategy.increment) 
            manifests: 'manifest.yml' 
      postRouteTraffic: 
        pool: server 
        steps:           
        - script: echo monitor application health...   
      on: 
        failure: 
          steps: 
          - script: echo clean-up, rollback...   
        success: 
          steps: 
          - script: echo checks passed, notify...

See also