Azure container Apps

CONTAINER APPS :

Containerization services in Azure

• Azure Container Instances (ACI): This service is useful when you need to execute a single container in an isolated environment. ACI supports both Windows and Linux containers and can start in a matter of seconds. Use cases include running a build server or bursting in the context of an AKS cluster.
• Azure Kubernetes Service (AKS): ACI provides no scaling nor load balancing functionalities. If you need these, then AKS is likely to better suit your needs. With AKS, you get a managed Kubernetes cluster in Azure, and you can access it and control it through the standard Kubernetes CLI commands.
• Azure Container Registry (ACR): this service gives you the ability to create a private registry for your container images and only give access to select users and groups (within your organization, for example). ACR also has a feature called “tasks” which can be leveraged in the context of image scanning and hardening.
• Azure Service Fabric: somewhat similar to AKS but the underlying orchestrator is proprietary.

Benefits of Azure Container Apps

Since ACA is a serverless offering, it will scale your applications automatically to meet the demand. Scaling can go from zero up to the maximum of replicas defined during the creation of the ACA instance. If no events (i.e., HTTP requests, messages in a Service Bus queue, …) are sent to our ACA instance then no pod is running which means that no cost is incurred.

The second benefit of ACA is the ability to execute multiple revisions (i.e., versions) of the same container in parallel. It can be useful for canary testing scenarios, and you can even redirect traffic between revisions.

A third benefit is that the load is automatically balanced across available replicas.

A fourth benefit is an availability, out-of-the-box, of the Dapr runtime, since Dapr is becoming more and more popular when it comes to building microservices applications.

There are also other benefits provided by ACA, such as the ability to manage application secrets from the application, the ability to monitor application logs centrally from Azure Log Analytics (which seems trivial but is very interesting especially in a microservices architecture where all microservices logs are aggregated into the same Log Analytics instance which greatly simplifies monitoring and debugging). There’s also the ability to execute containers from any registry (Docker Hub, ACR, …).

Limitations of Azure Container Apps

One limitation that we noticed, and that is worth mentioning here, is that ACA doesn’t allow you to manage the cluster using Kubernetes CLI commands (or any commands at all). Since ACA is a serverless offering, it makes total sense that you don’t have access to the underlying infrastructure and hence you can’t manage it yourself (that’s what serverless offerings are all about, right?). It makes sense but it is worth mentioning. Thus, if managing the Kubernetes cluster is what you need, then ACA is not the right service for you. You should instead consider AKS.