low-cost-ecs 0.0.6

Easy and low-cost ECS on EC2 server without a load balancer

Low-Cost ECS

A CDK construct that provides easy and low-cost ECS on EC2 server setup without a load balancer. TLS/SSL certificates are installed automatically on startup of the server and renewed by a scheduled state machine using certbot-dns-route53.

This construct is for development purposes only see Limitations.

Try it out!

The easiest way to see what this construct creates is to clone this repository and deploying sample server. Edit settings in bin/low-cost-ecs.ts and deploy cdk construct. Public hosted zone with your own domain is required.

git clone https://github.com/rajyan/low-cost-ecs.git
# edit settings in bin/low-cost-ecs.ts
npx cdk deploy

Access to configured recordDomainNames and see that the nginx sample server has been deployed.

Installation

To use this construct in your own cdk stack as a library,

npm install low-cost-ecs

import { Stack, StackProps } from 'aws-cdk-lib';
import { Construct } from 'constructs';
import { LowCostECS } from 'low-cost-ecs';

class SampleStack extends Stack {
    constructor(scope: Construct, id: string, props?: StackProps) {
        super(scope, id, props);

        const vpc = /** Your VPC */;
        const securityGroup = /** Your security group */;
        const serverTaskDefinition = /** Your task definition */;

        new LowCostECS(this, 'LowCostECS', {
            hostedZoneDomain: "rajyan.net",
            email: "[e-mail]",
            vpc: vpc,
            securityGroup: securityGroup,
            serverTaskDefinition: serverTaskDefinition
        });
    }
}

The required fields are hostedZoneDomain and email. Set your own task definition, and other props. Read LowCostECSProps documentation for details.

Why

ECS may often seem expensive when used for personal development purposes, because of the cost of load balancer. The application load balancer is a great service because it is easy to set up managed ACM certificates, it scales, and has dynamic port mapping, but it is over-featured for running 1 ECS service.

However, to run a ECS sever without a load balancer, you need to associate an Elastic IP to the host instance, and install your certificate by yourself. This construct aims to automate these work and deploying resources to run low-cost ECS server.

Cost

All resources except Route53 HostedZone should be included in AWS Free Tier if you are in the 12 Months Free period. After your 12 Months Free period, setting hostInstanceSpotPrice to use spot instances is recommended.

• EC2

  • t2,micro 750 instance hours (12 Months Free Tier)
  • 30GB EBS volume (12 Months Free Tier)

• ECS

  • No additional charge because using ECS on EC2

• EFS

  • Usage is very small, it should be free

• Cloud Watch

  • Usage is very small, and it should be included in the free tier
  • Enabling containerInsights will charge for custom metrics

Debugging

• SSM Session Manager

SSM manager is pre-installed (in ECS-optimized Amazon Linux 2 AMI) in the host instance and AmazonSSMManagedInstanceCore is added to the host instance role to access and debug in your host instance.

aws ssm start-session --target $INSTANCE_ID

• ECS Exec

Service ECS Exec is enabled, so execute commands can be used to debug in your server task container.

aws ecs execute-command \
--cluster $CLUSTER_ID \
--task $TASK_ID \
--container nginx \
--command bash \
--interactive

Limitations

The ecs service occupies the host port, only one service can be run at a time. The old task must be terminated before the new task launches, and this causes downtime on release. Also, if you make changes that require recreating service, you may need to manually terminate the task of old the service.