Azure Container Apps - Overview
Azure Container Apps, KEDA, and Dapr — what are these, and how do they work together? This article aims to give a high-level insight into Azure Container Apps and some of the Cloud Native ecosystem that surrounds this container orchestrator.
“Azure Container Apps is a fully managed Kubernetes-based application platform that helps you deploy apps from code or containers without orchestrating complex infrastructure.”
☁️ Understanding Azure Container Apps
In this section, we will take a look at the following:
- Overview of Microservices
- Getting started with Container APPS
- Differences between ACA and other Azure container solutions
Azure Container Apps is a fully managed serverless container service for building and deploying modern apps at scale - without managing infrastructure. It is built on top of Kubernetes and provides a simple, fully managed experience for deploying containerized applications.
🤔 Monoliths, Microservices and Containers? Huh?
To understand why we might need Container Apps, we need to go back to some of the elements of software development.
Containers can be a valuable tool for deploying and managing microservices, but they are not always necessary. Let's explore why you may not need containers for microservices and how they can generally help.
Microservices architecture is a software development approach where an application is built as a collection of small, loosely coupled services that can be developed, deployed, and scaled independently. Each microservice focuses on a specific business capability and communicates with other microservices through well-defined APIs.
While containers are not always necessary for deploying microservices, they offer benefits such as isolation, portability, scalability, and deployment consistency. Evaluating your specific requirements, existing infrastructure, and resource constraints will help determine whether containers are the right choice for your microservices architecture, and is intended to help you understand how it could be used, especially around some of the Cloud Native integration components.
Why you may not need containers for microservices:
- Simplicity: If your microservices are developed using a single programming language or framework and can be easily deployed on traditional servers or virtual machines, containers may not be necessary. In such cases, deploying microservices directly on servers or virtual machines can be simpler and more straightforward.
- Existing Infrastructure: If you already have a well-established infrastructure with efficient deployment processes and tools in place, containers may not be required. Leveraging your existing infrastructure can save time and effort in adopting and managing container technologies.
- Resource Constraints: Containers introduce additional overhead in terms of resource utilization. If you have limited resources or strict resource constraints, deploying microservices directly on servers or virtual machines may be more efficient.
However, how containers can generally help with microservices:
- Isolation: Containers provide a lightweight and isolated runtime environment for each microservice. This isolation ensures that changes or issues in one microservice do not affect others, improving overall system stability.
- Portability: Containers encapsulate the dependencies and runtime environment required by a microservice, making it highly portable. Microservices packaged as containers can be easily deployed and run on different platforms, such as local development machines, cloud environments, or on-premises servers.
- Scalability: Containers enable easy scaling of microservices. With container orchestration platforms like Kubernetes, you can dynamically scale the number of containers running a specific microservice based on demand, ensuring optimal resource utilization.
- Deployment Consistency: Containers provide a consistent deployment model, ensuring that the microservice runs the same way across different environments. This consistency simplifies the deployment process and reduces the chances of configuration-related issues.
First, let's take a look at Monoliths.
🏢 Monoliths
"In software engineering, a monolithic application is a single unified software application that is self-contained and independent from other applications but typically lacks flexibility"—Wikipedia.
Generally, monolithic architectures suffer from drawbacks that can delay application development and deployment. These drawbacks become especially significant when the product's complexity increases or when the development team grows in size.
The codebase of monolithic applications can be difficult to understand because it may be extensive. This can make it difficult for new developers to modify the code to meet changing business or technical requirements.
As requirements evolve or become more complex, it becomes difficult to correctly implement changes without hampering the code's quality and affecting the application's overall operation.
📖 References:
- monolithic architecture
- Challenges and patterns for modernizing a monolithic application into microservices
- Microservices with Azure Container Apps
Next up is Microservices, a more modular approach to software development.
🏗️ Microservices
At its core, the concept of the microservices architecture is an approach to application development in which a large application is built as a collection of modular and cooperating services.
However, in order to successfully achieve a robust microservices architecture, the underlying infrastructure must also be correctly designed. In fact, due to the distributed nature of the microservices architecture, the line between what used to be separate application details and implementation details grows blurrier.
Containers simplify the continuous deployment of microservices.
📖 References:
🚀 Deployment modes
The deployment of microservices and traditional monolith applications is usually done separately, which is an oversimplification.
Aspect | Microservices | Monolith Application |
---|---|---|
Service instantiation | Instantiate services instead of spinning up new machines => faster | Spinning up new machines for each instance => slower |
Hardware utilization | Better utilization of hardware | Less efficient utilization of hardware |
Cost | Optimized cost due to efficient resource usage | Potentially higher cost due to inefficient resource usage |
Time to market | Lower time to market: more confident when it comes to upgrading a service | Higher time to market: less confident when it comes to upgrading a service |
Independence | Services are independently implemented, deployed, scaled, and versioned | All components are tightly coupled and scaled together |
So, let's take a look at how Microservices and Containers can work together.
Let’s delve into the differences between microservices and containers:
Aspect | Microservices | Containers |
---|---|---|
Definition | Microservices are an architectural style that breaks down an application into small, autonomous services. These services communicate via well-defined interfaces using lightweight APIs. | A container is a technology that bundles an application along with all its dependencies into a package. This package allows the application to be deployed consistently across different environments, abstracting away differences in operating systems and underlying infrastructure. |
Structure | Microservices are self-contained and encapsulate their logic. They interact through well-defined interfaces, allowing independent development and deployment. | Containers ride on a host operating system, similar to virtual machines (VMs), but they share the OS kernel. This makes them lighter and faster to boot than VMs. Containers are hosted on a container runtime, which enables multiple containers (each several megabytes in size) to run on a single server. |
Popular Tools | Microservices can be developed with various programming languages and frameworks. | Docker is a well-known commercial container management solution, while Kubernetes (often referred to as K8s) is a widely used free and open-source container management system. |
Pros | Enhance maintainability, testability, and scalability. Organized around business capabilities and are typically owned by small teams. | Excellent for packaging and deploying applications consistently, regardless of the environment. More lightweight and faster to boot than VMs. |
Cons | Complexity in managing multiple services. Need for coordination and communication between services. | Requires knowledge of container management and orchestration tools. Potential security risks if not properly isolated. |
Use Case | Suitable for building modular, scalable applications. | Provides the infrastructure for running microservices, ensuring consistent deployment and management across different environments. |
Containers provide the infrastructure for running microservices, ensuring consistent deployment and management across different environments. Microservices, on the other hand, define the architectural approach for building modular, scalable applications.
🎛️ Container orchestration
Container orchestration is required to transition from deploying containers individually on a single host, to deploying complex multi-container apps on many machines. It requires a distributed platform, independent from infrastructure, that stays online through the entire lifetime of your application, surviving hardware failure and software updates.
Existing Container orchestration solutions include the following:
Solution | Description | Pros | Cons |
---|---|---|---|
Kubernetes | An open-source platform designed to automate deploying, scaling, and operating application containers. | Highly flexible and customizable. Large community support. | Complexity in setup and management. |
Docker Swarm | Docker's own native container orchestration. | Easy to set up. Integrated into Docker CLI. | Limited functionality compared to Kubernetes. |
Amazon ECS | A highly scalable, high-performance container orchestration service that supports Docker containers. | Deep integration with AWS services. | Only available on AWS. |
Azure Kubernetes Service (AKS) | Managed Kubernetes service provided by Azure. | Deep integration with Azure services. Managed Kubernetes with less operational complexity. | Only available on Azure. |
Azure Container Apps | A serverless container service that enables you to run containerized applications at scale. | Serverless, event-driven, and supports Linux containers. Deep integration with Azure services. | Only available on Azure. |
So, what is Container orchestration?
Container orchestration plays a crucial role in managing and scaling containerized applications. Here are some reasons why it’s essential:
Feature | Description |
---|---|
Scaling and Load Balancing | Container orchestration tools like Kubernetes allow you to dynamically scale your application by adding or removing containers based on demand. Load balancing ensures that incoming requests are distributed evenly across containers, preventing overload on any single instance. |
High Availability | Orchestration ensures that your application remains available even if individual containers fail. It automatically restarts failed containers or replaces them with healthy ones. |
Service Discovery and DNS | Containers come and go, making it challenging to keep track of their IP addresses. Orchestration tools provide service discovery and DNS resolution, allowing containers to find each other by name. |
Rolling Updates and Rollbacks | When deploying new versions of your application, orchestration allows for rolling updates. You can gradually replace old containers with new ones, minimizing downtime. In case of issues, you can easily roll back to a previous version. |
Configuration Management | Orchestration tools manage environment variables, secrets, and other configuration settings for containers. This centralizes configuration management and ensures consistency. |
Resource Optimization | Orchestration optimizes resource utilization by scheduling containers efficiently across nodes. It balances CPU, memory, and storage requirements. |
Networking and Security | Orchestration handles networking, including creating virtual networks for communication between containers. It also manages security policies, access controls, and network segmentation. |
Monitoring and Logging | Container orchestration platforms provide monitoring dashboards and logs. You can track performance, troubleshoot issues, and gain insights into your application. |
Container orchestration simplifies deployment, enhances reliability, and ensures efficient management of containerized applications.
👑 Container Apps
Azure Container Apps is a serverless platform that simplifies running containerized applications
- Azure Container Apps allows you to focus on your application logic without worrying about server configuration, container orchestration, or deployment details.
- It reduces operational complexity and saves costs by providing up-to-date server resources.
- Common use cases include deploying API endpoints, handling background processing jobs, event-driven processing, and running microservices.
You may be wondering what sort of applications you can build with Azure Container Apps.
Here are some common ones including:
- Deploying API endpoints
- Hosting background processing applications
- Handling event-driven processing
- Running microservices
With each of those applications, you can dynamically scale based on:
- HTTP traffic
- Event-driven processing
- CPU or memory load
- Any KEDA-supported scaler