Amazon ECS (Elastic Container Service) using EC2 launch type | Overview.

Amazon ECS (Elastic Container Service) using EC2 launch type - Overview.

Scope:

• Intro,
• The concept Amazon ECS - EC2 Launch Type,
• Architecture,
• Key Components,
• Pros (benefits) of EC2 Launch Type,
• Cons (limitations),
• Getting Started with ECS using EC2 Launch Type,
• Sample ECS EC2 Task Definition (JSON).

Intro:

• Amazon ECS with EC2 Launch Type. 
• This is where twtech runs its Docker containers on Amazon EC2 instances that twtech manages itself.

 The concept Amazon ECS - EC2 Launch Type

• Amazon ECS (Elastic Container Service) using the EC2 launch type.
• This means twtech can provision and manage a cluster of EC2 instances that act as container hosts.
• ECS schedules and runs twtech containers on these EC2 instances.

 Architecture Overview

         

AWS Useful link for Documentaion.

https://docs.aws.amazon.com/AmazonECS/latest/developerguide/launch-type-ec2.html

 Key Components

Component	Description
Cluster.	Group of EC2 instances that ECS manages.
Task Definition.	Blueprint for running containers (image, CPU, memory, ports).
Task.	Running instance of a Task Definition.
Service.	Ensures a specified number of tasks are always running.
ECS Agent.	Installed on EC2 instances, communicates with ECS.
EC2 Instances.	Container hosts (must use ECS-optimized AMI or compatible OS).

✅ Pros (benefits) of EC2 Launch Type

• Full control over EC2 instances (OS, networking, IAM, monitoring).
• Can run daemon services or tools like Prometheus, Fluentd, custom agents.
• More cost control with EC2 Reserved or Spot Instances.
• Easier integration with EBS volumes or custom networking.

❌ Cons (limitations)

• twtech must manage EC2 lifecycle (patching, autoscaling, etc.).
• Less "serverless" than Fargate – more overhead.
• Need to manage scaling of both instances and tasks.

 Getting started with ECS using EC2 Launch Type

1. Create ECS Cluster
• With EC2 capacity (twtech can use ECS optimized AMIs)
• Set IAM roles, networking (VPC, Subnets, Security Groups)
2. Register Task Definition
• Define container image, ports, CPU/memory, volumes, etc.
3. Launch Service or Task
• Select EC2 launch type
• Specify how many tasks to run
4. Auto Scaling (Optional)
• Use EC2 Auto Scaling groups
• Also possible to scale ECS tasks independently

 Sample ECS EC2 Task Definition (JSON)

# json

{

  "family": "twtech-ec2-app",

  "containerDefinitions": [

    {

      "name": "twtechwebapp",

      "image": "accountID.dkr.ecr.us-east-2.amazonaws.com/twtech-web-app:latest",

      "memory": 512,

      "cpu": 256,

      "portMappings": [

        {

          "containerPort": 80,

          "hostPort": 80

        }

      ],

      "essential": true

    }

  ]

}

 When twtech uses ECS with EC2 Launch Type

Use Case	Why ECS-EC2 is Suitable
Custom monitoring/logging agents.	Full access to the OS
Use of specialized EC2 types (e.g. GPU).	Supports all EC2 types
Long-running apps needing persistence.	Can mount EBS volumes
Existing EC2 infra in place.	Easy integration