Deploy a Docker container on Fargate through Serverless Framework

Amazon Elastic Container Service or (ECS) is a fully managed container orchestration service that allows you to host containers in AWS cloud. Fargate is a technology that manages the ECS clusters and scales according to load.

Creating the Docker file

Dockerfile is a file that is responsible for all the configuration of the container image. Below is a sample Dockerfile for running a node JS application.

FROM node:16

WORKDIR /app

COPY package*.json ./

RUN npm install

COPY . .

CMD [ "npm", "start" ]

For locally running on Mac Silicon Chips, use ` — platform=linux/amd64` tag either in FROM or while runing docker.

ECR repository

ECR stands for Elastic Container Repository, it is a repository service from AWS that allows it to upload container images.

  ECR:
    Type: AWS::ECR::Repository
    Properties:
      RepositoryName: repository-name

ECS task

ECS or Elastic Container Service task definition specifies the image to use with each container in the task and CPU and memory to allocate.

 TaskDefintion: 
    Type: AWS::ECS::TaskDefinition
    Properties: 
      ExecutionRoleArn:
        Fn::GetAtt:
          - TaskExecutionRole
          - Arn
      ContainerDefinitions: 
        - 
          Name: task-defintion-name
          Image: ECR repository URI
          logConfiguration:
            logDriver: awslogs
            options:
              awslogs-group: group name
              awslogs-region: region
              awslogs-create-group: true
          Cpu: 256
          Memory: 512
          Essential: true
      Cpu: 256
      Memory: 512
      NetworkMode: awsvpc
      RequiresCompatibilities: 
        - FARGATE
      TaskRoleArn:
        Fn::GetAtt:
          - TaskExecutionRole
          - Arn

Adding Fargate as required compatibility is responsible for scaling and maintaining the underlying infrastructure for running ECS task

ECS cluster

ECS cluster is responsible for handling the ECS tasks.

  VCUserReportsCluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: cluster-name
      CapacityProviders:
        - FARGATE
      DefaultCapacityProviderStrategy:
        - CapacityProvider: FARGATE
          Weight: 1

Create lambda to trigger ECS task and to set env variables

Finally write a lambda to trigger an ECS task and pass on any env variables required to run the container. The lambda can be configured to run as cron or on http invocation. The Lambda is also responsible for passing the role. The IAM role for lambda can have the iam:passrole action which allows it pass the role on to the container task on trigger.