A Complete Guide to Understand ECS to EKS Migration

Key Differences between ECS & EKS

Ease of Deployment

ECS is a straightforward and simple platform, whereas EKS is relatively complex and challenging with a higher requirement for configuration during ECS to EKS migration.

As ECS is an AWS (Amazon Web Services) native solution, there is no control plane; Whereas EKS is based on Kubernetes, there is a control plane (managed). EKS means Elastic Kubernetes System. Elastic Kubernetes System or EKS is a fully managed Kubernetes system or service. One must note that EKS usually executes or runs containerized applications with the help of Kubernetes orchestration and management on AWS. ECS vs. EKS debate is essential to know before migration.

ECS is a fully managed service or container orchestration service; it does not have as many moving parts, components, and functionality as K8s. As soon as the ECS is set up, it is immediately ready to use for deployment tasks with the help of the AWS console.

Contrary to this, EKS is much more challenging and requires technical and complex deployment configuration and skillset. Also, after setting it up in the AWS console, the user is required to configure and deploy Pods via Kubernetes, using Kops. It introduces the concept of Kubernetes Pods which help to deploy and manage containers generally. However, it is interesting to note that EKS works together seamlessly with ECS with shared operations. 


ECS is an AWS proprietary technology, whereas EKS is based on Kubernetes, which is open-source.

While both ECS and EKS are AWS-specific services, Kubernetes as a service can be used with any cloud provider and on-premises. Using a managed Kubernetes service like EKS, you are still investing in a cloud-agnostic platform, both in terms of tech and expertise. However, this is not the case for ECS, as it is offered exclusively for the AWS cloud.


In ECS to EKS migration both supports IAM (Identity & Access Management) (Identity & Access Management) roles per task/container.

Back in the day, one could not relate an IAM role to an EKS container. However, in 2019 the functionality upgraded.


EKS and ECS both require straightforward and upfront payment of computer resources used by containers. It could be on EC2 instances, and serverless Fargate compute.

EKS is subjected to an additional cost of running Master nodes (Control plane), as EKS manages the master nodes (that run across multiple availability zones) separate from the worker nodes ($0.10/hour/cluster). At the same time, that is not the case with ECS. Interestingly there is no extra charge when it comes to using ECS.  


The real difference is how each of them handles or manages networking and support component services. ECS can help you with two significant matters:

  • Allocate ENIs for a task
  • Support and handle EC2 for up to 120 different tasks

With EKS, ENIs can be allocated to and shared between Kubernetes pods, enabling the user to place up to 750 Kubernetes pods per EC2 instance (depending on instance type). It can achieve a relatively higher container density as opposed to ECS.


On the other hand in Cloud services, Kubernetes comes with the concept of “namespaces.” The feature isolates workloads(pods) that run within the same cluster. Although it seems useless and futile at first, it is, in fact, very beneficial.

For instance, it is possible to have staging and production namespaces while sharing resources running in the same cluster. It would lead to a decreased spare capacity within the cluster.

Community and Support

Kubernetes, an open-source platform, has a large and continuously growing community besides the obvious benefits. On the other hand, being proprietary, ECS gets less community support, although you will have excellent corporate support from AWS.

Moreover, Kubernetes (EKS) has a broader reach than ECS while considering its multi-platform support.

ECS to EKS glossary

In ECS to EKS, migration requires knowledge and familiarity with a few Kubernetes terms.

ECS and K8s building blocks comparison: In this part, you review the building blocks of ECS and Kubernetes, which will help you grasp the potential differences between the two.

EKS Worker Node: These EC2 instances run within your workloads or pods.

  • Infrastructure as Code (IAC): This framework defines infrastructure as code that usually comes in the Git repository. Additionally, there is a Git-like diff source or output in case of a mismatch between codes and the infrastructure within a cloud. Prominent examples include Pulumi, Terraform, etc.
  • Helm – It is one of the most common and famous packaging solutions in Kubernetes.
  • ALB (Application Load Balancer)
  • NLB (Network Load Balancer)
  • Internet Gateway – An internet gateway is a horizontally scaled, redundant, and available VPC (Virtual Private Cloud) component that allows communication between your VPC and the internet.
  • VPC – The Amazon Virtual Private Cloud allows a very smooth launch of AWS resources into a pre-defined virtual network. The virtual network is similar to a conventional network that operates within your data house or center. It is beneficial for a scalable and flexible AWS Infrastructure.
  • ECS comes with its own terminology that you are familiar with. Let’s see how ECS transforms into the EKS habitat.
  • ECS Task Definition <> EKS Kubernetes Deployment YAML
  • ECS Task <> EKS Kubernetes Pod
  • ECS Cluster <> EKS Cluster

This is how we can migrate from ECS to EKS.  

How to migrate from ECS to EKS

Migrating from ECS to EKS is a six-step process. The steps are: 

Rephrasing ECS Task Definition files for deployment to YAMLs

To begin with, you have to rewrite the ECS Task Definition files for deploying YAMLS in Kubernetes. You cannot skip this stage because it defines the basic differences between ECS to EKS migration.

Spin up your Environment

You have to constantly spin up and work around the respective environments present within the EKS. People typically use IAC (Infrastructure as Code) for that – Terraform, CloudFormation, or Pulumi. Here is some good news for you. Some of the widely known and famous IAC tools support EKS.

Assuming that you know the Docker concept and have an inventory of application photos packaged and readily available for use:

  • You have the option to use Terraform features, including Kubernetes provider, to transport your Deployment YAMLs for a smooth IAC flow.
  • There is also an option to use Helm Provider, provided your application packages also use Helm.
  • Similarly, some people also use CloudFormation because of the easy deployment of workloads to EKS clusters. But it works only when the applications are Helm packaged.

There are many ways to complete the tasks, but everything has advantages and disadvantages. However, this simple solution is enough for now.

Configure your CI/CD pipelines

You have to configure CI/CD pipelines for deploying the applications in the EKS cluster.


ECS and EKS have similar networking qualities: ALB & NLB. You can use the basic networking constructs you are currently familiar with in ECS. This article might be handy if you want more details about ingress with ALB.

Run some tests

To ensure that everything works perfectly, you have to run some suit tests in the new configurations.

Shift the traffic to an EKS Cluster

It varies because of the configuration settings. But to have an idea, let’s look at the prerequisites.

  • You may have to switch your domain’s IP for a Load Balancer within an EKS cluster. That is how you ensure application traffic is directed toward the EKS cluster.
  • For stateful applications, you need to think about other things, such as ensuring that the K8s-based application transitions to being the primary user of the database (smooth shift from ECS to the EKS app for using the database for writing tasks).


Therefore, when it comes to capable and reliable orchestration solutions, ECS to EKS migration both help with the management of containers at scale. Choosing between EKS and ECS depends on the size and nature of the project.

Large or hybrid deployments – prefer EKS for its more robust customization and improved portability between clouds and on-premises systems. Under two conditions, you should use EKS.

  • There are containers working on Kubernetes.
  • You seek advanced orchestration solutions with better compatibility

Legacy workloads – For moving to a container environment, a straightforward Kubernetes is the best solution. It allows users to create a development, testing, and production environment on-premises and then move it to the cloud.

For somebody new to containerization and seeking a simple and readily available solution, ECS is the perfect option. Also, for small-scale deployments, you can go for ECS because of the seamless and efficient deployment and configuration. ECS has a free control plane.

Reach out to us at [email protected] to book a free consultation session with our AWS team.


Q: How do I migrate from ECS to EKS? 

Ans: To migrate from ECS to EKS, follow these steps: 

  • Assessment: Evaluate your existing ECS setup and applications. 
  • Containerization: Convert your ECS containers to Kubernetes-compatible containers. 
  • Cluster Setup: Create an EKS cluster. 
  • Application Deployment: Deploy your containers on EKS. 
  • Testing: Thoroughly test your applications. 
  • Gradual Transition: Gradually transition traffic to EKS. 

Q: Why migrate from ECS to EKS? 

Ans: Migrate for enhanced scalability, Kubernetes features, and a broader ecosystem. 

Q: What is the difference between ECS and EKS? 

Ans: ECS is Amazon’s native container orchestration service, while EKS provides managed Kubernetes. EKS offers more control and flexibility. 

Q: What is the first step in configuring ECS? 

Ans: The first step in configuring ECS is defining your task definitions, specifying container configurations, and setting up your cluster’s infrastructure. 

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