/azure-prepare

Container Apps Day-2 Operations

Operational tasks for running Container Apps in production: restart, exec, logs, environment updates, and secret rotation.

Restart and Lifecycle

💡 Tip: Restarting a revision replaces all running replicas gracefully. No new revision is created.

Exec into a Container

Open a shell inside a running replica for debugging:

# Interactive shell
az containerapp exec -n $APP -g $RG --command /bin/sh

# Target a specific replica and container
az containerapp exec -n $APP -g $RG \
  --replica $REPLICA_NAME \
  --container $CONTAINER_NAME \
  --command /bin/sh

⚠️ Warning: Exec sessions are for debugging only. Changes to the container filesystem are lost on restart.

Log Streaming

Real-time Logs

# Stream system logs
az containerapp logs show -n $APP -g $RG --type system --follow

# Stream application (console) logs
az containerapp logs show -n $APP -g $RG --type console --follow

# Filter to a specific revision or replica
az containerapp logs show -n $APP -g $RG \
  --type console --revision $REV --follow

Log Analytics (KQL)

Query historical logs via the Container Apps environment's Log Analytics workspace:

// Azure Monitor destination (new environments — default)
ContainerAppConsoleLogs
| where ContainerAppName == "my-app"
| where TimeGenerated > ago(1h)
| project TimeGenerated, Log, RevisionName
| order by TimeGenerated desc

// Log Analytics destination (legacy environments)
// ContainerAppConsoleLogs_CL
// | where ContainerAppName_s == "my-app"
// | project TimeGenerated, Log_s, RevisionName_s

Environment Variable Updates

Updating environment variables creates a new revision:

# Set or update env vars
az containerapp update -n $APP -g $RG \
  --set-env-vars "DB_HOST=newhost.postgres.database.azure.com" \
                 "CACHE_TTL=300"

# Remove an env var
az containerapp update -n $APP -g $RG \
  --remove-env-vars "OLD_SETTING"

Bicep — Env Vars with Secret References

configuration: {
  secrets: [
    { name: 'db-password', value: dbPassword }  // or use keyVaultUrl + identity
  ]
}
template: {
  containers: [
    {
      name: 'api'
      image: '${acrName}.azurecr.io/api:latest'
      env: [
        { name: 'DB_HOST', value: dbHost }
        { name: 'DB_PASSWORD', secretRef: 'db-password' }
      ]
    }
  ]
}

Secret Management

Create and Update Secrets

# Add a secret (use Key Vault references in production — avoid plaintext secrets)
az containerapp secret set -n $APP -g $RG \
  --secrets "db-password=<secret-value>"

# Reference a Key Vault secret (managed identity required)
az containerapp secret set -n $APP -g $RG \
  --secrets "db-password=keyvaultref:https://myvault.vault.azure.net/secrets/db-pwd,identityref:/subscriptions/.../userAssignedIdentities/my-id"

⚠️ Warning: Avoid passing plaintext secrets on the command line — they may appear in shell history and process listings. Prefer Key Vault references. If you must use plaintext, use shell substitution like --secrets "key=$(cat secret.txt)" to avoid literals on the command line.

💡 Tip: Use Key Vault references instead of plain-text secrets. The Container App pulls the latest value on each new revision or replica start.

Secret Rotation Workflow

1. Update the secret value in Key Vault
2. Create a new revision to pick up the updated value:

   az containerapp revision copy -n $APP -g $RG

3. Verify the new revision is healthy
4. Shift traffic to the new revision

⚠️ Warning: Existing replicas do NOT hot-reload Key Vault references. A new revision or replica restart is required.

Health Monitoring

Common Troubleshooting