Containers in AWS

In this chapter, you will learn about various patterns commonly used by many top technology companies worldwide, including Netflix, Microsoft, Amazon, Uber, eBay, and PayPal. These companies have survived and thrived by adopting cloud technologies and the design patterns that are popular on the cloud. It is hard to imagine how these companies could exist in their present form if the capabilities delivered by the cloud did not exist. In addition, the patterns, services, and tools presented in this chapter make the cloud much more powerful.

Containers are an evolution of virtualization technology – virtualized hardware and virtualized machines are what you have been used to for many years. Many vendors provide this kind of virtualization, including AWS.

In this chapter, you will first learn about the concept of containerization with the most popular container platforms, Docker, Kubernetes, OpenShift, and the related offerings in AWS.

In this chapter...

Understanding containerization

It’s almost 6 o’clock, and dinner time is getting close. You are getting hungry. And you feel like cooking some roasted vegetables. Time to fire up the grill. But think about everything that’s going to be required:

• Vegetables
• A grill
• Matches
• Charcoal or gas
• Condiments
• Tongs

So, it’s more than just roasted vegetables.

Some companies specialize in bundling all the necessary elements to facilitate this process and you can buy everything in a package. A similar analogy would be if you went to a restaurant. The cook handles all of the elements listed here for you; all you have to do is eat.

It’s the same with software. Installing something like a website is much more than just installing your code. It might require the following:

• An Operating System (OS)
• A database
• A web server
• An app server
• Configuration files
• Seeding data...

Virtual machines (VMs) and virtualization

In order to understand VMs and virtualization, let’s first look at an analogy. For many of us, one of our goals is to own a house. Can you picture it? Three bedrooms, a beautiful lawn, and a white picket fence, maybe? For some of us, at least for now, that dream may not be achievable, so we must settle on renting an apartment in a big building.

You can think of the beautiful house as a normal standalone server that serves only one client or application. The apartment, in this case, is the VM. The apartment serves its purpose by providing housing with some shared services. It might not be as beautiful and convenient as the house, but it does the job. With the house, you are wasting resources if you live alone because you can only use one room at a time. Similarly, with a standalone server, especially if you have an application with variable traffic, you will have lulls in your traffic where a lot of the capacity of the machine is...

Containers versus VMs

There is a definite line of distinction between VMs and containers. Containers allow you to isolate applications within an OS environment. VMs allow you to isolate what appears to the users and represent it as a completely different machine to the user, even with its own OS.

The following diagram illustrates the difference:

Figure 13.1: VMs versus containers

As we can see in Figure 13.1, in the case of VM architecture, each virtual slice has its own OS and all the slices sit on top of the hypervisor. In the case of container architecture, there is only one OS installed for all the instances. There is only one container engine, but multiple binaries and applications can be installed for each slice.

Containers share a kernel at the OS level; all components are built into the OS kernel, which makes containers fast to start and, when compared to VMs, they generally have lower overhead.

VMs have a more defined isolation boundary...

Learning about Docker

It would be a disservice to you, reader, for us to talk about containers and not mention Docker. Docker is not the only way to implement containers, but it is a popular container software; perhaps the most popular one. Docker has almost become synonymous with the term container. Docker, Inc., the product maker, follows a freemium model, offering both a free and a premium version. Docker was released to the public in 2013 at the PyCon Conference.

As container software, Docker can package an application with its libraries, configuration files, and dependencies. Docker can be installed in Linux environments as well as on Windows. The virtual containers that Docker enables allow applications to run in isolation without affecting any other processes running on the same physical machine.

Docker is often used by both developers and system administrators, making it an essential tool for many DevOps teams. Developers like using it because it allows them to focus...

Amazon Elastic Container Service (ECS)

The core of container management is automation, which includes container build/deploy pipelines, observability for ensuring health, Service Level Agreements (SLAs), and security at all steps. Container orchestration is an important piece that manages computers, networking, and storage and handles critical aspects such as scheduling and auto-scaling. This is where ECS comes in, providing an end-to-end orchestration service for containers.

Amazon Elastic Container Service (ECS) is a container orchestration service. It enables users to launch EC2 containers in the form of tasks. In this case, a task is one or more EC2 instances with a Docker container. These EC2 instances can send traffic to other AWS services, such as AWS RDS. A cluster of EC2 instances may run within an ECS Auto Scaling group with predefined scaling rules. For this to happen, the ECS container agent will constantly poll the ECS API, checking whether new containers need to...

Learning about Kubernetes

Kubernetes is an open-source container orchestration platform that is popular for managing and deploying containerized applications. It automates many of the manual tasks involved in deploying, scaling, and maintaining containerized applications. Kubernetes can be thought of as a train conductor; it orchestrates and manages all the rail cars (containers), making sure that they reach their destination reliably and efficiently. Kubernetes provides features such as automatic scaling, self-healing, and rolling updates, which can help to improve the availability and performance of your containerized applications.

Kubernetes also provides a rich set of APIs that can be used to automate the deployment and management of containerized applications. This makes it easy to integrate Kubernetes with other tools and platforms, such as CI/CD pipelines and monitoring systems.

Kubernetes, often abbreviated as K8s, was invented by Google. Kubernetes was developed by...

Amazon Elastic Kubernetes Service (Amazon EKS)

AWS provides a managed service called Amazon Elastic Kubernetes Service (EKS) that simplifies the deployment, scaling, and management of containerized applications using Kubernetes on AWS. EKS eliminates the need to provision and manage your own Kubernetes clusters, which simplifies the process of running Kubernetes workloads on AWS. It automatically scales and updates the Kubernetes control plane and worker nodes, and it integrates with other AWS services, such as ELB, RDS, and S3.

Amazon EKS is simply a managed wrapper around the Kubernetes kernel, which ensures that existing Kubernetes applications are fully compatible with Amazon EKS. This allows you to use the same Kubernetes APIs, tooling, and ecosystem that you use for on-premises or other cloud-based deployments, with the added benefits of the AWS infrastructure and services.

Amazon EKS facilitates running Kubernetes with effortless availability and scalability. It greatly...

Learning about AWS Fargate

AWS Fargate is a serverless way to run containers. ECS and EKS support running containerized workloads using AWS Fargate.

Let’s look at an example to better understand how Fargate helps you run serverless containers. Without Fargate, you have an EC2 instance with multiple tasks running on it. So here, to support the tasks, you have to manage the underlying instance, such as the instance OS, the container runtime, and the ECS agent, in the case of Amazon ECS. This is still quite a bit of operational overhead. You have to patch and update the OS, ECS/EKS agent, and so on, while also scaling the instance fleet for optimal utilization. All of these tasks are still required, adding management layers to your application.

AWS Fargate simplifies the management of ECS/EKS services and enables users to focus on application development rather than infrastructure management. With AWS Fargate, the provisioning of infrastructure and the management of servers...

Red Hat OpenShift Service on AWS (ROSA)

OpenShift is another container platform developed and supported by Red Hat. It’s built on top of Red Hat Enterprise Linux and Kubernetes, two of the world’s largest and fastest-growing open-source projects, and adds several services to offer a well-rounded platform experience out of the box. These include cluster services such as monitoring, managing, and updating the cluster; cluster services such as built-in CI/CD pipelines and logging; application services such as databases, language runtimes, and many others through what’s known in Kubernetes as Operators; and developer services such as a rich console, CLI, and tools for code editors, IDEs and more.

Red Hat OpenShift Service on AWS (ROSA) is a fully managed service provided by Red Hat and jointly supported by AWS. ROSA offers pay-as-you-go billing options (hourly and annual) on a single invoice through AWS and provides the option to contact either Red Hat or AWS...

Choosing between AWS container services

So, at this point, you are probably asking yourself when you should choose Amazon ECS, EKS, or ROSA as the right solution. When choosing between ECS, EKS, and ROSA, it’s important to consider the specific requirements of your application and use case:

• EKS is a managed Kubernetes service that allows you to easily deploy, manage, and scale containerized applications on the AWS cloud. It provides a fully managed Kubernetes control plane and integrates with other AWS services such as Elastic Load Balancing and Amazon RDS. If you are already familiar with Kubernetes and want to leverage its flexibility and scalability, EKS is a good choice.
• ECS is a container orchestration service that allows you to deploy, manage, and scale containerized applications on the AWS cloud. It provides a simple and easy-to-use interface for deploying and managing containerized applications and integrates with other AWS services such as Elastic...

Summary

In this chapter, you explored in depth what containers are. You also learned about the different types of container tools that are available. In particular, you investigated Docker. Docker is quite a popular container tool today, and it is a foundational piece of software for many successful companies. You learned about Amazon ECS, AWS’s way of managing containers at scale. You learned about how it helps to run Docker containers.

You also learned about the orchestration tool Kubernetes, which is quite popular and helps many companies simplify their DevOps processes. You looked at how Kubernetes and Docker can work together, as well as with other AWS services. These tools were specifically created to host and maintain containers. You also spent some time reviewing Amazon EKS and how it works with Kubernetes.

You learned about running the serverless container option Fargate and when to choose running containers with EC2 or Fargate. Furthermore, you learned about...