Exploring Deployment Jobs strategies in Azure DevOps multi-stage YAML – Canary for AKS example

Exploring Deployment Jobs strategies in Azure DevOps multi-stage YAML – Canary for AKS example

A Canary Deployment strategy for Azure Kubernetes Service (AKS) involves deploying updates to a small set of Kubernetes pods or services to validate changes before scaling them across the entire AKS environment.

This helps to ensure that updates don’t cause disruptions and issues can be resolved early.

Steps to Implement Canary Deployment for AKS in Azure DevOps

1. Deploy to Canary AKS Environment: Deploy updates to a small subset of AKS pods.

2. Monitor and Validate: Perform monitoring, testing, and validation on the Canary pods.

3. Approval and Full Deployment: After successful Canary testing, move to a full-scale deployment.

Example Multi-stage YAML for Canary Deployment to AKS

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stages:
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  - stage: Canary
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    jobs:
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      - job: DeployCanaryAKS
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        steps:
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          - script: |
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              kubectl apply -f ./canary-deployment.yaml
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              kubectl rollout status deployment/myapp -n my-namespace
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          - script: |
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              kubectl get pods -n my-namespace
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              kubectl logs $(kubectl get pods -n my-namespace | grep myapp-canary | awk '{print $1}') -n my-namespace
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          - hooks:
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              - approval:
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                  name: Canary Approval
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                  condition: eq(variables['Build.Status'], 'Succeeded')
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  - stage: Production
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    dependsOn: Canary
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    jobs:
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      - job: DeployProductionAKS
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        steps:
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          - script: |
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              kubectl apply -f ./production-deployment.yaml
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              kubectl rollout status deployment/myapp -n my-namespace

Details of Canary Deployment for AKS

1. Canary Deployment: Deploy a small number of AKS pods using a dedicated Canary deployment configuration (canary-deployment.yaml).

2. Monitoring and Validation: Validate the health and stability of Canary pods using commands like kubectl get pods and kubectl logs.

3. Approval: Use an approval gate to ensure successful Canary validation before proceeding to full deployment.

4. Production Deployment: Deploy updates to the full AKS cluster using the production configuration (production-deployment.yaml).

Detailed Steps

1. Deploy to Canary AKS:

   • Apply a dedicated Canary deployment configuration (canary-deployment.yaml).

   • Monitor the status of the deployment using kubectl rollout status.

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   - script: |
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      kubectl apply -f ./canary-deployment.yaml
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      kubectl rollout status deployment/myapp -n my-namespace
   

2. Validate Canary Deployment: Get the list of pods and logs to ensure the Canary deployment is stable.

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   - script: |
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      kubectl get pods -n my-namespace
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      kubectl logs $(kubectl get pods -n my-namespace | grep myapp-canary | awk '{print $1}') -n my-namespace
   

3. Approval Hook: Implement an approval step after Canary validation to ensure only stable deployments move forward.

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   hooks:
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   - approval:
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         name: Canary Approval
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         condition: eq(variables['Build.Status'], 'Succeeded')
   

4. Production Deployment: Once Canary deployment is validated, proceed with deploying the production configuration.

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   - script: |
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      kubectl apply -f ./production-deployment.yaml
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      kubectl rollout status deployment/myapp -n my-namespace
   

Benefits of Canary Deployment for AKS

1. Reduced Risk: Smaller scale deployment to validate changes before scaling.

2. Early Detection: Quickly identify and fix issues without impacting the entire AKS cluster.

3. Progressive Rollout: Gradual expansion of updates, reducing downtime.

4. Monitoring and Validation: Enhanced visibility into deployment health through logging and status checks.