MitchyBAwesome / fargate-cmd-demo

Deploying an application using AWS Fargate from the command line

AWS Fargate from the Command-Line

We all love a good command-line demo. Here is one I put together recently for demonstrating a few things, firstly Docker multi-stage builds, and secondly how a simple web service written in Go could be deployed to AWS Fargate using nothing but the command line.

What's cool about that I hear you ask?

What's cool about it is that at no point during this demo am I deploying, configuring or going to have to manage ANY servers.

Is it "serverless" ... is it containers? YES!

Let’s take a look:

1. Create some environment variables

ACCOUNT_ID="000000000"

REGION="us-west-2"

REPO="go-http-server"

2. Start by creating an ECR (Elastic Container Registry) repository.

aws ecr create-repository --repository-name ${REGION}

3. Login to ecr

$(aws ecr get-login --no-include-email --region ${REGION})

4. Build docker image

docker build -t ${REPO} .

5. Tag docker image

docker tag ${REPO}:latest ${ACCOUNT_ID}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:latest

6. Push docker image

docker push ${ACCOUNT_ID}.dkr.ecr.${REGION}.amazonaws.com/${REPO}:latest

7. Create Cluster

aws ecs create-cluster --cluster-name fargate-cluster --region ${REGION}

8. Get VPC Details

vpcid=$(aws ec2 describe-vpcs | jq '.Vpcs[] | select (.IsDefault == true) | .VpcId' | sed -e 's/^"//' -e 's/"$//')

9. Get subnet details

subnets=$(aws ec2 describe-subnets --filters "Name=vpc-id,Values=${vpcid}" | jq '.Subnets[].SubnetId') && echo $subnets

10. Create ELB security group

aws ec2 create-security-group \
--description "security group for ALB" \
--group-name "security-group-for-alb" \
--region ${REGION} | jq '.GroupId'

11. Configure ELB security group ingress rule to allow ELB to connect to tasks.

aws ec2 authorize-security-group-ingress \
--group-id <GroupId_from_previous_command> \
--protocol tcp \
--port 80 \
--cidr 0.0.0.0/0

12. Create a load balancer and get the ELB ARN.

aws elbv2 create-load-balancer \ 
--name go-http-server \ 
--subnets subnet-111111 \
subnet-222222 \
subnet-333333 \ 
--security-groups <ALB_Security_GroupId> \
| jq '.LoadBalancers[].LoadBalancerArn'

13. Create a target group

aws elbv2 create-target-group \
--name fargate-targets \
--target-type ip \
--protocol HTTP \
--port 80 \
--vpc-id ${vpcid} | jq '.TargetGroups[].TargetGroupArn'

14. Create a listener

aws elbv2 create-listener \
--load-balancer-arn <load_balancer_arn> \
--protocol HTTP \
--port 80 \
--default-actions Type=forward,TargetGroupArn=<target_group_arn>

15. Register Task Definition

aws ecs register-task-definition \
--cli-input-json file://./go-http-server.json \
--region ${REGION} --query 'taskDefinition.taskDefinitionArn'

16. Create security group for the tasks

aws ec2 create-security-group \
--description "security group for fargate task" \
--group-name "security-group-for-fargate-task" \
--region ${REGION} | jq '.GroupId'

17. Configure security group ingress rule to allow ELB to connect to tasks.

aws ec2 authorize-security-group-ingress \
--group-id \
--protocol tcp \
--port 8000 \
--source-group <alb_security_group_id>

18. Create Service

aws ecs create-service --cluster fargate-cluster --service-name go-http-server \
--task-definition <task_definition> --desired-count 2 --launch-type "FARGATE" \
--network-configuration "awsvpcConfiguration={subnets=[ <command_separated_list_subnets> ],securityGroups=[<security_group>],assignPublicIp=ENABLED}" \
--load-balancers targetGroupArn=<target_group_arn>,containerName=<container_name>,containerPort=<container_port> \
--region ${REGION}

19. Grab the DNSName of the load balancer by querying the load balancer ARN.

url=$(aws elbv2 describe-load-balancers \
--load-balancer-arns <load_balancer_arn> \
| jq '.LoadBalancers[].DNSName' | sed -e 's/^"//' -e 's/"$//') && curl $url