ECS Docker Web Application

AWS ECS to create a sample Docker image for running a web application

Prerequisites

• AWS CLI configured
• Docker installed
• AWS ECR repository created
• ECS cluster created

Project Structure:

CN_DevOps_Project/
├── app/
│   └── index.html
├── Dockerfile
├── ecs-task-definition.json
└── README.md

Prerequisite

• AWS CLI
• DOCKER ENGINE/DESKTOP
• Create user >> add to admin group >> apply full-admin-access policy >> security >> create access keys
• install awscli >> aws --version >> aws configure
• enter access key, secret access key, region-code, output-json

Steps

1. Clone the repository:

git clone https://github.com/y-runwal/CN_DevOps_Project.git
cd CN_DevOps_Project

2. Build Docker Image:

docker build -t CN_DevOps_Project .
# Example with a specific tag:
sudo docker build -t yrunwal/CN_DevOps_Project .

3. Push to ECR: Create public repo | name-yuvrajrunwal >> view push commands

aws ecr get-login-password --region <YOUR_REGION> | docker login --username AWS --password-stdin <YOUR_ECR_URL>
docker tag ecs-docker-webapp:latest <YOUR_ECR_URL>:latest
docker push <YOUR_ECR_URL>:latest
example:
aws ecr get-login-password --region <YOUR_REGION> | docker login --username AWS --password-stdin <YOUR_ECR_URL>
docker tag CN_DevOps_Project:latest <YOUR_ECR_URL>:latest
docker push <YOUR_ECR_URL>:latest

4. Create ECS Cluster: Navigate to ECS in the AWS Management Console and create a new ECS cluster (Fargate).

5. Register ECS Task Definition: Use the ecs-task-definition.json to register a new task definition in ECS.

Create ECS Cluster | cluster name - mycluster IAM - Create Role - Elastic Container Service(Allows ECS to create and manage AWS resources on your behalf) | Name - ECSRole IAM - Create Role - Elastic Container Service Task (Allows ECS tasks to call AWS services on your behalf) | Name - ECSTaskRole

note down ECSRole, ECSServiceRole ARN, Image URL to update in JSON file examples:

• arn:aws:iam::021891610508:role/ECSRole
• arn:aws:iam::021891610508:role/aws-service-role/ecs.amazonaws.com/AWSServiceRoleForECS
• 112609445401.dkr.ecr.ap-south-1.amazonaws.com/yuvraj_mit/cndevops_project

{
  "family": "ecs-docker-webapp",
  "networkMode": "awsvpc",
  "containerDefinitions": [
    {
      "name": "webapp-container",
      "image": "<YOUR_ECR_URL>:latest",
      "essential": true,
      "portMappings": [
        {
          "containerPort": 80,
          "hostPort": 80,
          "protocol": "tcp"
        }
      ],
      "memory": 512,
      "cpu": 256
    }
  ],
  "requiresCompatibilities": [
    "FARGATE"
  ],
  "cpu": "256",
  "memory": "512",
  "executionRoleArn": "arn:aws:iam::021891610508:role/ECSRole",
  "taskRoleArn": "arn:aws:iam::021891610508:role/aws-service-role/ecs.amazonaws.com/AWSServiceRoleForECS"
}

Task Definition >> Create New Definition Deploy >> Create Service

7. Deploy to ECS: Create a service in your ECS cluster, link it to the task definition, and deploy the web application. Expose the service via a load balancer to access the web app

8. Access the Web Application: After the service is running, access the application via the Load Balancer’s DNS. The application is a simple HTML page served by an Nginx web server.

Troubleshoot

ERROR: Cannot connect to the Docker daemon.... Is the docker daemon running? Solution: Make sure docker engine/docker desktop is in running state.