Azure Container Apps

Azure Container Apps is a serverless container platform that lets you run microservices and containerised applications without managing Kubernetes infrastructure. Built on top of Kubernetes, KEDA (event-driven autoscaling), Dapr (distributed application runtime), and Envoy (traffic management), Container Apps provides the benefits of Kubernetes without the operational complexity.

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What Makes Container Apps Different?

Aspect	AKS	Container Apps
Kubernetes API	Full access	Not exposed
Control plane	You configure it	Fully managed
Scaling	HPA, KEDA, cluster autoscaler	Built-in, automatic, scale to zero
Networking	You manage ingress, CNI, policies	Built-in HTTP ingress, managed VNet
Complexity	High — full K8s knowledge required	Low — deploy containers, set rules
Best for	Complex architectures, full control	APIs, microservices, event-driven apps

Container Apps is not a simplified AKS — it is a different abstraction layer. You never see nodes, pods, or deployments. You work with container apps, revisions, and scaling rules.

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Core Concepts

Container Apps Environment

An environment is the secure boundary around a group of container apps. Apps in the same environment share:

• A virtual network (or you can bring your own VNet)
• A Log Analytics workspace for centralised logging
• Dapr components (if configured)

Think of it as the equivalent of a Kubernetes namespace + cluster infrastructure.

az containerapp env create \
  --resource-group rg-containers \
  --name my-environment \
  --location uksouth

Container App

A container app is your application — one or more containers running from a specified image.

az containerapp create \
  --resource-group rg-containers \
  --environment my-environment \
  --name my-api \
  --image mycompanyacr.azurecr.io/myapi:1.0 \
  --registry-server mycompanyacr.azurecr.io \
  --registry-identity system \
  --target-port 8080 \
  --ingress external \
  --min-replicas 1 \
  --max-replicas 10 \
  --cpu 0.5 \
  --memory 1Gi

Revisions

Every change to a container app creates a new revision — an immutable snapshot of the app's configuration and container image. Revisions enable:

• Blue/green deployments — run two versions simultaneously
• Canary releases — route a percentage of traffic to the new revision
• Instant rollback — activate a previous revision immediately

# Split traffic: 80% to v1, 20% to v2
az containerapp ingress traffic set \
  --resource-group rg-containers \
  --name my-api \
  --revision-weight my-api--v1=80 my-api--v2=20

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Scaling Rules

Container Apps supports multiple scaling triggers through built-in KEDA integration:

HTTP Scaling

Scale based on the number of concurrent HTTP requests:

az containerapp create \
  --scale-rule-name http-rule \
  --scale-rule-type http \
  --scale-rule-http-concurrency 100 \
  --min-replicas 0 \
  --max-replicas 20

When there are zero requests, the app scales to zero replicas (and you pay nothing).

Event-Driven Scaling

Scale based on external event sources:

# Container App YAML
properties:
  template:
    scale:
      minReplicas: 0
      maxReplicas: 30
      rules:
        - name: queue-rule
          azureQueue:
            queueName: orders
            queueLength: 10
            auth:
              - secretRef: storage-connection
                triggerParameter: connection

Supported Scale Triggers