This is continued from AWS CloudFormation: 04 – Build and deploy pipeline .

Background

I want a web server Docker instance.

What we need?

1. A VPC with 2 subnets because we need to have a load balancer also.
2. A load balancer so we can have a fixed endpoint with flexible Docker instances.
3. A container cluster to host the Docker web server.
4. A container task definition to tell how to run the Docker web server.

How to do it?

This is what we are going to do:

Open 02-autoscaling-template.yaml from previous post and save as 05-container-webserver-template.yaml .

Unwanted Resources

We don't need all the resources from the previous YAML file, so we need to do some cleanup first. Delete these resources

• WebServerLaunchTemplate
• WebServerAutoScalingGroup

We don't need the SSH access also, so delete the port 22 from the WebServerSecurityGroup.

Load Balancer

The previous load balancer is setup to work with EC2 instances. We need to change it to work with Docker instances. Change this resource:

1

WebServerLoadBalancerTargetGroup:     Type: AWS::ElasticLoadBalancingV2::TargetGroup     Properties:       Port: 80       Protocol: HTTP       VpcId: !Ref VPC       TargetGroupAttributes:         - Key: deregistration_delay.timeout_seconds           Value: "30"       TargetType: ip

Change the TargetType to ip so it works with Docker instances.

Container

We need to setup to container. We will use AWS Fargate service. It will handle all the Docker services for us. We just need to setup the container task definition. Add these resources:

1	WebServerContainerCluster:     Type: AWS::ECS::Cluster	The container cluster.
2	WebServerContainerTaskDefinition:     Type: AWS::ECS::TaskDefinition     Properties:       ContainerDefinitions:         - Name: WebServer           Image: nginx           PortMappings:             - ContainerPort: 80       RequiresCompatibilities:         - FARGATE       NetworkMode: awsvpc       Cpu: 256       Memory: 512	The container task definition.
3	WebServerContainerService:     Type: AWS::ECS::Service     Properties:       Cluster: !Ref WebServerContainerCluster       DesiredCount: 1       LaunchType: FARGATE       TaskDefinition: !Ref WebServerContainerTaskDefinition       NetworkConfiguration:         AwsvpcConfiguration:           AssignPublicIp: ENABLED           SecurityGroups:             - !Ref WebServerSecurityGroup           Subnets:             - !Ref PublicSubnet       LoadBalancers:         - ContainerName: WebServer           ContainerPort: 80           TargetGroupArn: !Ref WebServerLoadBalancerTargetGroup     DependsOn: WebServerLoadBalancerHttpListener	Launch the container into the cluster.

Parameters

We have removed the SSH access to the Docker instance. We don't need any parameters here, so just remove all.

The URL to the load balancer is available at the Outputs section. Update the stack then you should be able to see the NGINX test page with the load balancer URL.