Modernising Applications with Containers: Embracing the Future of Development

As businesses continue to embrace digital transformation, modernising legacy applications is often at the forefront of their cloud strategies. Containers have emerged as a key technology in this journey, offering a more efficient, scalable, and portable way to manage applications across diverse environments. In this blog post, we’ll explore how containers are revolutionising application modernisation, the benefits they bring, and how you can leverage AWS services like Amazon ECS and AWS Fargate to deploy and manage containers effectively.

What Are Containers?

At their core, containers are lightweight, standalone packages that include everything an application needs to run—code, runtime, system tools, libraries, and settings. Unlike traditional virtual machines (VMs), containers share the host system’s OS kernel, making them more resource-efficient and faster to start up. This unique approach allows developers to build, test, and deploy applications consistently across different environments, whether on-premises, in the cloud, or in a hybrid setting.

The Benefits of Containerisation

1. Scalability

• Rapid Scaling: Containers can be spun up or down quickly, enabling applications to handle varying loads with ease. This elasticity is crucial for modern applications that often experience unpredictable traffic patterns.
• Microservices Architecture: Containers naturally lend themselves to microservices, where different parts of an application can be scaled independently. This means you can allocate more resources to critical components without over-provisioning others.

2. Portability

• Consistent Environments: Containers ensure that applications run the same regardless of where they are deployed. This consistency minimizes the “it works on my machine” problem, streamlining the development process.
• Cloud Agnostic: Containerized applications can be moved across different cloud providers or on-premises environments with minimal changes, providing flexibility and avoiding vendor lock-in.

3. Efficient Resource Utilisation

• Lower Overhead: Since containers share the host OS kernel, they require fewer resources than traditional VMs, allowing for higher density and lower costs.
• Optimized Performance: Containers can be fine-tuned to allocate exactly the resources an application needs, leading to more efficient use of compute power and storage.

Containerising Legacy Applications: The Process

Modernising legacy applications through containerisation is a strategic way to extend their lifespan while reaping the benefits of modern infrastructure. Here’s a step-by-step guide to containerising legacy applications:

1. Assessment

• Evaluate Dependencies: Start by identifying the application’s dependencies, such as libraries, databases, and third-party services. Understanding these will help in containerising the application effectively.
• Suitability Check: While the vast majority of applications can be put in containers, it makes sense to assess whether the application should be “containerised”.

2. Containerisation

• Create Docker Images: Begin by packaging the application into a Docker image, which includes the application code, dependencies, and runtime environment.
• Testing: Use a staging environment to test the containerized application, ensuring it behaves as expected in a containerized setup.

3. Deployment

• Deploy to a Container Orchestrator: Once tested, deploy the containerized application to a container orchestration platform like Kubernetes or Amazon ECS.
• Monitor and Optimize: Continuously monitor the application’s performance in the containerized environment, making adjustments to resource allocation as necessary.

Best Practices for Container Management

Successfully managing containers requires a blend of strategic planning and the right tools. Here are some best practices to follow:

1. Use Immutable Infrastructure

Treat your containers as immutable. Once a container is created and deployed, it should not be modified. If updates are needed, create a new container image and redeploy.

2. Implement Proper Networking and Security

Ensure that containers are correctly networked, with clear rules for how they communicate internally and externally. Security should be a priority, with proper isolation, regular vulnerability scanning, and role-based access control (RBAC).

3. Resource Management

Use resource limits and requests to control how much CPU and memory each container can use. This prevents a single container from monopolising resources, ensuring fair allocation across all running containers.

4. Logging and Monitoring

Implement robust logging and monitoring solutions to track container performance and detect issues early. Tools like AWS CloudWatch can be integrated with your containerized applications to provide real-time insights.

Deploying and Managing Containers with AWS Services

AWS offers many powerful tools to help you deploy and manage containers effectively, with Amazon ECS and AWS Fargate being two of the most popular services.

1. Amazon ECS (Elastic Container Service)

Amazon ECS is a fully managed container orchestration service that makes it easy to deploy, manage, and scale containerized applications. With ECS, you can define your application’s architecture, set up scaling policies, and integrate with other AWS services for a seamless container management experience.

2. AWS Fargate

AWS Fargate is a serverless compute engine for containers that works with Amazon ECS. Fargate eliminates the need to provision and manage servers, allowing you to focus on building and running your applications. It automatically scales your containers and ensures that they have the resources they need, simplifying the process of deploying containerized applications.

Conclusion

Containers are at the heart of modernising applications, providing unmatched scalability, portability, and resource efficiency. By containerising legacy applications, organisations can extend their lifespan while embracing the benefits of modern infrastructure. Using container orchestrators like Amazon ECS and AWS Fargate further simplifies the deployment and management of containerized applications, making it easier for businesses to innovate and stay competitive in today’s fast-paced digital landscape.

As you continue on your cloud journey, embracing containers can be a transformative step, unlocking new possibilities for your applications and IT strategy.