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Bicep: Deploying Docker Containers on Azure

This guide demonstrates how to use Bicep to deploy Docker containers to Azure Container Instances (ACI). It includes best practices, step-by-step deployment, troubleshooting, and common pitfalls for engineers working with Azure, Docker, and Infrastructure as Code.

Best Practices for Bicep & Docker

  • Use parameterization for image, CPU, memory, and ports to support multiple environments.
  • Always use specific image tags (avoid latest) for reproducibility.
  • Store secrets (e.g., registry credentials) in Azure Key Vault and reference them securely.
  • Use resource group and location parameters for portability.
  • Validate Bicep files before deployment: 
    az bicep build --file main.bicep
az deployment group validate --resource-group <rg> --template-file main.bicep
  • Use outputs to retrieve container IPs or other runtime info for automation.

Step-by-Step: Deploy a Docker Container with Bicep

  1. Create a Resource Group: 
    az group create --name exampleRG --location eastus
  2. Deploy the Bicep Template: 
    az deployment group create --resource-group exampleRG --template-file main.bicep
  3. Check Deployment Output:
    • The output will include the public IP address of your container.
  4. List Resources: 
    az resource list --resource-group exampleRG
  5. View Container Logs: 
    az container logs --resource-group exampleRG --name acilinuxpublicipcontainergroup

Real-Life Example: Parameterized Bicep for CI/CD

  • Integrate Bicep deployment in GitHub Actions or Azure Pipelines for automated container rollouts.
  • Example GitHub Actions step: ```yaml
    • name: Deploy to Azure uses: azure/arm-deploy@v1 with: resourceGroupName: exampleRG template: main.bicep parameters: image=myrepo/myapp:1.2.3 ```

Common Pitfalls

  • Using latest image tag (can cause unexpected updates)
  • Not exposing required ports or using wrong protocol
  • Insufficient CPU/memory for container workload
  • Forgetting to set restart policy (may cause containers to stop unexpectedly)
  • Not checking logs for failed deployments

References

```bicep @description(‘Name for the container group’) param name string = ‘acilinuxpublicipcontainergroup’

@description(‘Location for all resources.’) param location string = resourceGroup().location

@description(‘Container image to deploy. Should be of the form repoName/imagename:tag for images stored in public Docker Hub, or a fully qualified URI for other registries. Images from private registries require additional registry credentials.’) param image string = ‘mcr.microsoft.com/azuredocs/aci-helloworld’

@description(‘Port to open on the container and the public IP address.’) param port int = 80

@description(‘The number of CPU cores to allocate to the container.’) param cpuCores int = 1

@description(‘The amount of memory to allocate to the container in gigabytes.’) param memoryInGb int = 2

@description(‘The behavior of Azure runtime if container has stopped.’) @allowed([ ‘Always’ ‘Never’ ‘OnFailure’ ]) param restartPolicy string = ‘Always’

resource containerGroup ‘Microsoft.ContainerInstance/containerGroups@2021-09-01’ = { name: name location: location properties: { containers: [ { name: name properties: { image: image ports: [ { port: port protocol: ‘TCP’ } ] resources: { requests: { cpu: cpuCores memoryInGB: memoryInGb } } } } ] osType: ‘Linux’ restartPolicy: restartPolicy ipAddress: { type: ‘Public’ ports: [ { port: port protocol: ‘TCP’ } ] } } }

output containerIPv4Address string = containerGroup.properties.ipAddress.ip ```plaintext

bash az group create --name exampleRG --location eastus az deployment group create --resource-group exampleRG --template-file main.bicep plaintext

bash az resource list --resource-group exampleRG plaintext

bash az container logs --resource-group exampleRG --name acilinuxpublicipcontainergroup plaintext