Deploy AWS Target Group, Elastic Load Balancer & ELB Listener Using CloudFormation

Welcome back to the series of AWS Cloudformation For Beginners 👨🏻‍💻. In this blog I am going to deploy resources which are very important as part of your web stack deployments in which we will deploy Deploy Target Group, Elastic Load Balancer & ELB Listener.

If you are a beginner and want to start your journey towards infra-as-code developer as part of your devops role buckle up 🚴‍♂️ and lets get started and understand core cloudformation concepts by implementing it…🎬

🎨 Diagrammatic Representation 🎨

Template Components Planning Before Build

👨🏻‍💻Build Target Group, Elastic Load Balancer & ELB Listener👨🏻‍💻

🔳 Parameters

✦ CustomVPC :- Using this parameter for VPC “AWS::EC2::VPC::Id” we can list existing VPC list into the account and select anyone from them. Apart from this list we can also you default value if no value is selected in the parameter.
✦ PublicSubnet: Using this parameter for Subnet “AWS::EC2::Subnet::Id” we can list existing subnet list from the account and select anyone from them. Apart from this list we can also you default value if no value is selected in the parameter.

Parameters:
  CustomVPC:
    Description: Select One VPC available in your existing account
    Type: AWS::EC2::VPC::Id
    Default: "<your default VPC ID>"
  PublicSubnet1:
    Description: Select one public subnet available in your existing account
    Type: AWS::EC2::Subnet::Id
    Default: "<your default public subnet id>"
  PublicSubnet2:
    Description: Select one public subnet available in your existing account
    Type: AWS::EC2::Subnet::Id
    Default: "<your default public subnet id>"

 🔳 Resources

✦ InstanceSecurityGroup:- Creating Security group and enabling ingress with http and ssh port.
➖ GroupName:- This property is used to mention security group name.
➖ GroupDescription:- This property is used to mention security group description and its mandatory property for this resource.
➖ SecurityGroupIngress:- This property is used to add ingress rules for [udp/tcp] ports enabled secured access to your resources.
➖ Tags:- One of the most important property used in all resources. Always make sure to attach tags for all your resources.

 InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      VpcId: !Ref CustomVPC
      GroupName: "AllowEc2Traffic"
      GroupDescription: "Enable SSH access and HTTP access on the inbound port for EC2"
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: 0.0.0.0/0
      Tags:
        - Key: Name
          Value: InstanceSecurityGroup

 ✦ UbuntuInstance:- As part of this resource we use type “AWS::EC2::Instance”.

➖ ImageId:- This property is used to mention EC2 image ID based on which you want to launch your EC2 Instance.
➖ KeyName:- This property is used to mention keynameby using which you can connect to your EC2 instance.
➖ InstanceType:- This property is used to mention which type of instance you want to launch smal/medium/large based on your requirement.
➖ SecurityGroupIds:- This property is used to add list of security group you want to attach to your EC2 instance for enabling access control based on your security requirements.
➖ Tags:- One of the most important property used in all resources. Always make sure to attach tags for all your resources.

  UbuntuInstance1:
    Type: AWS::EC2::Instance
    Properties:
      KeyName: CustomVPC
      ImageId: ami-04505e74c0741db8d
      SubnetId: !Ref PublicSubnet1
      InstanceType: t2.micro
      SecurityGroupIds:
        - !Ref InstanceSecurityGroup
      Tags:
        - Key: Name
          Value: UbuntuInstance1
  UbuntuInstance2:
    Type: AWS::EC2::Instance
    Properties:
      KeyName: CustomVPC
      ImageId: ami-04505e74c0741db8d
      InstanceType: t2.micro
      SubnetId: !Ref PublicSubnet2
      SecurityGroupIds:
        - !Ref InstanceSecurityGroup
      Tags:
        - Key: Name
          Value: UbuntuInstance2

✦ ELBTargetGroup:- Real work of target group is to inform a loadbalancer to whom he should route traffic like EC2/Fixed IP Address/lambda.
➖ HealthCheckIntervalSeconds: The approximate amount of time, in seconds, between health checks of an individual target.
➖ HealthCheckTimeoutSeconds: The amount of time, in seconds, during which no response from a target means a failed health check.
➖ HealthyThresholdCount: The number of consecutive health checks successes required before considering an unhealthy target healthy.
➖ UnhealthyThresholdCount: The number of consecutive health check failures required before considering a target unhealthy.
➖ VpcId: Id of your existing VPC.
➖ TargetType: The type of target that you must specify when registering targets with this target group. You can specific alb/instance/ip/lambda.
➖ Targets: As part of this property we are mentioning the instance id’s to be added as targets.

ELBTargetGroup:
   Type: 'AWS::ElasticLoadBalancingV2::TargetGroup'
   Properties:
     HealthCheckIntervalSeconds: 6
     HealthCheckTimeoutSeconds: 5
     HealthyThresholdCount: 2
     Port: 80
     Protocol: HTTP
     UnhealthyThresholdCount: 2
     VpcId: !Ref CustomVPC
     TargetType: instance
     Targets: 
       - Id: !Ref UbuntuInstance1
         Port: 80
       - Id: !Ref UbuntuInstance2
         Port: 80

 ✦ ELBSecurityGroup:- Creating Security group and enabling ingress with http and ssh port.

➖ GroupName:- This property is used to mention security group name.
➖ GroupDescription:- This property is used to mention security group description and its mandatory property for this resource.
➖ SecurityGroupIngress:- This property is used to add ingress rules for [udp/tcp] ports enabled secured access to your resources.
➖ Tags:- One of the most important property used in all resources. Always make sure to attach tags for all your resources.

 ELBSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupName: "ELBTraffic"
      GroupDescription: "Enable HTTP access on the inbound port for ELB"
      VpcId: !Ref CustomVPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 443
          ToPort: 443
          CidrIp: 0.0.0.0/0
      Tags:
        - Key: Name
          Value: ELBSecurityGroup

✦ ElasticLoadBalancer:- Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets and virtual appliances in one or more Availability Zones (AZs).As part of this resource we use type “AWS::ElasticLoadBalancingV2::LoadBalancer”.
➖ Subnets: The IDs of the public subnets. You can specify only one subnet per Availability Zone.
➖ SecurityGroups: List IDs of the security groups for the load balancer.

ElasticLoadBalancer:
    Type: 'AWS::ElasticLoadBalancingV2::LoadBalancer'
    Properties:
      Subnets: 
        - !Ref PublicSubnet1
        - !Ref PublicSubnet2
      SecurityGroups: 
        - !Ref ELBSecurityGroup

✦ ElbListener:- A listener is a process that checks for connection requests, using the protocol and port that you configure. The rules that you define for a listener determine how the load balancer routes requests to its registered targets. As part of this resource we use type “AWS::ElasticLoadBalancingV2::Listener”.
➖ DefaultActions: The actions for the default rule. You cannot define a condition for a default rule.
➖ LoadBalancerArn: Refer Amazon Resource Name (ARN) of the load balancer the we have created in above code block.

  ElbListener:
   Type: 'AWS::ElasticLoadBalancingV2::Listener'
   Properties:
     DefaultActions:
       - Type: forward
         TargetGroupArn: !Ref ELBTargetGroup
     LoadBalancerArn: !Ref ElasticLoadBalancer
     Port: '80'
     Protocol: HTTP

🔳 Outputs

Its always a best practice to print output for your resources.
✦ outputmyUbuntuInstance: A reference to the created EC2 Instance.
✦ outputInstanceSecurityGroup:- A reference to the created Security Group.
✦ outputELBTargetGroup: A reference to the created Target Group.
✦ outputELBSecurityGroup: A reference to the created Security Group.
✦ outputElasticLoadBalancer: A reference to the created Elastic Load Balancer.
✦ outputElasticListener: A reference to the created Elastic Load Balancer Listener.

Outputs:
  outputInstanceSecurityGroup:
    Description: A reference to the created security group
    Value: !Ref InstanceSecurityGroup
  outputUbuntuInstance:
    Description: A reference to the created EC2 Instance
    Value: !Ref UbuntuInstance1
  outputUbuntuInstance:
    Description: A reference to the created EC2 Instance
    Value: !Ref UbuntuInstance2
  outputELBTargetGroup:
    Description: A reference to the created Target Group
    Value: !Ref ELBTargetGroup
  outputELBSecurityGroup:
    Description: A reference to the created Security Group
    Value: !Ref ELBSecurityGroup
  outputElasticLoadBalancer:
    Description: A reference to the created Elastic Load Balancer
    Value: !Ref ElasticLoadBalancer
  outputElasticListener:
    Description: A reference to the created Elastic Load Balancer Listener
    Value: !Ref ElbListener

 🔳 Final Resource Stack

CustomVPC:
    Description: Select One VPC available in your existing account
    Type: AWS::EC2::VPC::Id
    Default: "<your default VPC ID>"
  PublicSubnet1:
    Description: Select one public subnet available in your existing account
    Type: AWS::EC2::Subnet::Id
    Default: "<your default public subnet id>"
  PublicSubnet2:
    Description: Select one public subnet available in your existing account
    Type: AWS::EC2::Subnet::Id
    Default: "<your default public subnet id>"
Resources: 
  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      VpcId: !Ref CustomVPC
      GroupName: "AllowEc2Traffic"
      GroupDescription: "Enable SSH access and HTTP access on the inbound port for EC2"
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: 0.0.0.0/0
      Tags:
        - Key: Name
          Value: InstanceSecurityGroup
  UbuntuInstance1:
    Type: AWS::EC2::Instance
    Properties:
      KeyName: CustomVPC
      ImageId: ami-04505e74c0741db8d
      SubnetId: !Ref PublicSubnet1
      InstanceType: t2.micro
      SecurityGroupIds:
        - !Ref InstanceSecurityGroup
      Tags:
        - Key: Name
          Value: UbuntuInstanceWithUserdata1
  UbuntuInstance2:
    Type: AWS::EC2::Instance
    Properties:
      KeyName: CustomVPC
      ImageId: ami-04505e74c0741db8d
      InstanceType: t2.micro
      SubnetId: !Ref PublicSubnet2
      SecurityGroupIds:
        - !Ref InstanceSecurityGroup
      Tags:
        - Key: Name
          Value: UbuntuInstanceWithUserdata2
  ELBTargetGroup:
   Type: 'AWS::ElasticLoadBalancingV2::TargetGroup'
   Properties:
     HealthCheckIntervalSeconds: 6
     HealthCheckTimeoutSeconds: 5
     HealthyThresholdCount: 2
     Port: 80
     Protocol: HTTP
     UnhealthyThresholdCount: 2
     VpcId: !Ref CustomVPC
     TargetType: instance
     Targets: 
       - Id: !Ref UbuntuInstance1
         Port: 80
       - Id: !Ref UbuntuInstance2
         Port: 80
  ELBSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupName: "ELBTraffic"
      GroupDescription: "Enable HTTP access on the inbound port for ELB"
      VpcId: !Ref CustomVPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 443
          ToPort: 443
          CidrIp: 0.0.0.0/0
      Tags:
        - Key: Name
          Value: ELBSecurityGroup
  ElasticLoadBalancer:
    Type: 'AWS::ElasticLoadBalancingV2::LoadBalancer'
    Properties:
      Subnets: 
        - !Ref PublicSubnet1
        - !Ref PublicSubnet2
      SecurityGroups: 
        - !Ref ELBSecurityGroup
  ElbListener:
   Type: 'AWS::ElasticLoadBalancingV2::Listener'
   Properties:
     DefaultActions:
       - Type: forward
         TargetGroupArn: !Ref ELBTargetGroup
     LoadBalancerArn: !Ref ElasticLoadBalancer
     Port: '80'
     Protocol: HTTP

 🔊 To view entire github code click here

1️⃣ Lets validate our template 👨‍💻

aws cloudformation validate-template --template-body file://<file path>

2️⃣ After successful template verification lets create stack using our template 👨‍💻

aws cloudformation create-stack --stack-name launchelbwithlistener --template-body file://<file path>

3️⃣ Check if the stack we created via template is completed successfully 👨‍💻

aws cloudformation list-stack-resources --stack-name launchelbwithlistener

4️⃣ Describe stack and its resources to view its properties 👨‍💻

aws cloudformation describe-stacks --stack-name launchelbwithlistener

aws cloudformation describe-stack-resources --stack-name launchelbwithlistener

5️⃣ Check events for stack formation 👨‍💻

aws cloudformation describe-stack-events --stack-name launchelbwithlistener

❗️❗️Important AWS Documentation To Be Viewed❗️❗️

⛔️ Target Groups
⛔️ LoadBalancer
⛔️ ELB Listener
⛔️ EC2
⛔️ Parameters
⛔️ Outputs

🥁🥁 Conclusion 🥁🥁

In this blog I am going to deploy resources which are very important as part of your web stack deployments in which we will create
✦ Ubuntu EC2 instance with Security group.
✦ Target group and its association with EC2.
✦ Elastic Load Balancer, ELB listener, ELB Security Group and its association with Target Groups.
I have used AWS CLI command to deploy these template and trust me AWS CLI is the realtime hero and I would suggest you to get acquainted towards it. Going forward I will be releasing further parts to this CloudFormation journey

📢 Stay tuned for my next blog…..

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Author - Dheeraj Choudhary

I am an IT Professional with 11+ years of experience specializing in DevOps & Build and Release Engineering, Software configuration management in automating, build, deploy and release. I blog about AWS and DevOps on my YouTube channel, which focuses on content such as, AWS, DevOps, open source, AI-ML and AWS community activities.