Exploring Deployment Jobs strategies in Azure DevOps multi-stage YAML – RunOnce

Exploring Deployment Jobs strategies in Azure DevOps multi-stage YAML – RunOnce

In Azure DevOps Multi-stage YAML pipelines, the RunOnce deployment job strategy is used when a job should run only once, regardless of how many environments or stages are involved. This strategy is useful for tasks that should be executed only once, such as setting up infrastructure, performing migrations, or applying a one-time configuration.

Key Use Cases for RunOnce Strategy

1. Initial Setup: Set up infrastructure or configurations that should only run once.

2. Database Migrations: Perform migrations or schema updates in a one-time job.

3. Resource Initialization: Initialize resources like key vaults or service bus configurations.

Example Multi-stage YAML with RunOnce Deployment Job

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stages:
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  - stage: Initialize
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    jobs:
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      - job: RunOnceJob
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        runsOn: self-hosted
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        steps:
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          - script: echo "Running initial setup..."
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            displayName: "Setup Initialization"
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  - stage: Deploy
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    dependsOn: Initialize
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    jobs:
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      - job: DeployJob
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        steps:
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          - script: echo "Deploying application..."
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            displayName: "Application Deployment"
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  - stage: Verify
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    dependsOn: Deploy
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    jobs:
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      - job: VerifyJob
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        steps:
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          - script: echo "Verifying deployment..."
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            displayName: "Deployment Verification"

Details of the RunOnce Job

1. RunOnceJob:

   • This job runs only once, usually during the initialization or initial setup stage.

   • It does not run in subsequent stages or environments unless explicitly re-triggered.

   xxxxxxxxxx
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   job: RunOnceJob
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   runsOn: self-hosted
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   steps:
   4
      - script: echo "Running initial setup..."
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         displayName: "Setup Initialization"
   

2. Following Stages: Subsequent stages (Deploy, Verify) depend on the Initialize stage, which contains the RunOnceJob.

Advantages of RunOnce Deployment Strategy

1. Single Execution: Ensures specific tasks (like setting up configurations or initializing resources) are executed only once.

2. Consistency: Useful for enforcing infrastructure as code or initial environment setup.

3. Simplified Maintenance: Avoids redundant execution of jobs, reducing unnecessary compute or resource usage.

Other Considerations

1. Dependencies: The RunOnceJob can be dependent on other tasks (e.g., preparation of infrastructure).

2. Integration: Can be integrated with tools such as Terraform or ARM templates for infrastructure setup.

Summary

That's all for this blog. Kindly write back through your comments and let me know if you need more details or examples of how to apply this in a specific scenario. Thanks for reading.