An example CloudFormation template for deployment of a container to ECS, including integration with an Application Load Balancer.

ecs.yml

AWSTemplateFormatVersion: "2010-09-09"
Parameters:
  Subnet1ID:
    Type: String
  Subnet2ID:
    Type: String
  VPCID:
    Type: String
Resources:
  Cluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: deployment-example-cluster
  LogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: deployment-example-log-group
  ExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: deployment-example-role
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: ecs-tasks.amazonaws.com
            Action: sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy
  ContainerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupName: ContainerSecurityGroup
      GroupDescription: Security group for NGINX container
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
  TaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      Family: deployment-example-task
      Cpu: 256
      Memory: 512
      NetworkMode: awsvpc
      ExecutionRoleArn: !Ref ExecutionRole
      ContainerDefinitions:
        - Name: deployment-example-container
          Image: nginx:1.17.7
          PortMappings:
            - ContainerPort: 80
          LogConfiguration:
            LogDriver: awslogs
            Options:
              awslogs-region: !Ref AWS::Region
              awslogs-group: !Ref LogGroup
              awslogs-stream-prefix: ecs
      RequiresCompatibilities:
        - EC2
        - FARGATE
  Service:
    Type: AWS::ECS::Service
    Properties:
      ServiceName: deployment-example-service
      Cluster: !Ref Cluster
      TaskDefinition: !Ref TaskDefinition
      DesiredCount: 2
      LaunchType: FARGATE
      NetworkConfiguration:
        AwsvpcConfiguration:
          AssignPublicIp: ENABLED
          Subnets:
            - !Ref Subnet1ID
            - !Ref Subnet2ID
          SecurityGroups:
            - !GetAtt ContainerSecurityGroup.GroupId
      LoadBalancers:
        - TargetGroupArn: !Ref TargetGroup
          ContainerPort: 80
          ContainerName: deployment-example-container
  LoadBalancerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupName: LoadBalancerSecurityGroup
      GroupDescription: Security group for load balancer
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Name: deployment-example-load-balancer
      Subnets:
        - !Ref Subnet1ID
        - !Ref Subnet2ID
      SecurityGroups:
        - !GetAtt LoadBalancerSecurityGroup.GroupId
  LoadBalancerListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      LoadBalancerArn: !Ref LoadBalancer
      Port: 80
      Protocol: HTTP
      DefaultActions:
        - Type: forward
          TargetGroupArn: !Ref TargetGroup
  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      TargetType: ip
      Name: deployment-example-target-group
      Port: 80
      Protocol: HTTP
      VpcId: !Ref VPCID