How to create a Network Load Balancer using AWS CLI
Hello Everyone
Welcome to CloudAffaire and this is Debjeet.
In the last blog post, we have discussed Network Load Balancer concepts.
https://cloudaffaire.com/network-load-balancer-nlb/
In this blog post, we will create a Network Load Balancer using AWS CLI.
How to create a Network Load Balancer using AWS CLI:
Step 1: Create a custom VPC for your Network Load Balancer.
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#################################### ## Create A Network Load Balancer ## #################################### ## Prerequisite: AWS CLI installed and configured with proper access ## https://cloudaffaire.com/category/aws/aws-cli/ ##---------------------------------- ## Create custom vpc for your nlb ## ##---------------------------------- ## Create a directory for this demo mkdir aws_nlb_demo && cd aws_nlb_demo ## Create a VPC with DNS hostname enabled AWS_VPC_ID=$(aws ec2 create-vpc \ --cidr-block 10.0.0.0/16 \ --query 'Vpc.{VpcId:VpcId}' \ --output text) && aws ec2 modify-vpc-attribute \ --vpc-id $AWS_VPC_ID \ --enable-dns-hostnames "{\"Value\":true}" ## Create two public subnets AWS_SUBNET_PUBLIC_ONE_ID=$(aws ec2 create-subnet \ --vpc-id $AWS_VPC_ID --cidr-block 10.0.1.0/24 \ --availability-zone ap-south-1a --query 'Subnet.{SubnetId:SubnetId}' \ --output text) && AWS_SUBNET_PUBLIC_TWO_ID=$(aws ec2 create-subnet \ --vpc-id $AWS_VPC_ID --cidr-block 10.0.2.0/24 \ --availability-zone ap-south-1b --query 'Subnet.{SubnetId:SubnetId}' \ --output text) && aws ec2 modify-subnet-attribute \ --subnet-id $AWS_SUBNET_PUBLIC_ONE_ID \ --map-public-ip-on-launch && aws ec2 modify-subnet-attribute \ --subnet-id $AWS_SUBNET_PUBLIC_TWO_ID \ --map-public-ip-on-launch ## Create an Internet Gateway AWS_INTERNET_GATEWAY_ID=$(aws ec2 create-internet-gateway \ --query 'InternetGateway.{InternetGatewayId:InternetGatewayId}' \ --output text) && aws ec2 attach-internet-gateway \ --vpc-id $AWS_VPC_ID \ --internet-gateway-id $AWS_INTERNET_GATEWAY_ID ## Create a route table AWS_CUSTOM_ROUTE_TABLE_ID=$(aws ec2 create-route-table \ --vpc-id $AWS_VPC_ID \ --query 'RouteTable.{RouteTableId:RouteTableId}' \ --output text ) && aws ec2 create-route \ --route-table-id $AWS_CUSTOM_ROUTE_TABLE_ID \ --destination-cidr-block 0.0.0.0/0 \ --gateway-id $AWS_INTERNET_GATEWAY_ID ## Associate the public subnet with route table AWS_ROUTE_TABLE_ASSOID_ONE=$(aws ec2 associate-route-table \ --subnet-id $AWS_SUBNET_PUBLIC_ONE_ID \ --route-table-id $AWS_CUSTOM_ROUTE_TABLE_ID \ --query 'AssociationId' \ --output text) && AWS_ROUTE_TABLE_ASSOID_TWO=$(aws ec2 associate-route-table \ --subnet-id $AWS_SUBNET_PUBLIC_TWO_ID \ --route-table-id $AWS_CUSTOM_ROUTE_TABLE_ID \ --query 'AssociationId' \ --output text) ## Create a security group aws ec2 create-security-group \ --vpc-id $AWS_VPC_ID \ --group-name myvpc-security-group \ --description 'My VPC non default security group' ## Get security group ID's AWS_DEFAULT_SECURITY_GROUP_ID=$(aws ec2 describe-security-groups \ --filters "Name=vpc-id,Values=$AWS_VPC_ID" \ --query 'SecurityGroups[?GroupName == `default`].GroupId' \ --output text) && AWS_CUSTOM_SECURITY_GROUP_ID=$(aws ec2 describe-security-groups \ --filters "Name=vpc-id,Values=$AWS_VPC_ID" \ --query 'SecurityGroups[?GroupName == `myvpc-security-group`].GroupId' \ --output text) ## Create security group ingress rules aws ec2 authorize-security-group-ingress \ --group-id $AWS_CUSTOM_SECURITY_GROUP_ID \ --ip-permissions '[{"IpProtocol": "tcp", "FromPort": 22, "ToPort": 22, "IpRanges": [{"CidrIp": "0.0.0.0/0", "Description": "Allow SSH"}]}]' && aws ec2 authorize-security-group-ingress \ --group-id $AWS_CUSTOM_SECURITY_GROUP_ID \ --ip-permissions '[{"IpProtocol": "tcp", "FromPort": 0, "ToPort": 65535, "IpRanges": [{"CidrIp": "0.0.0.0/0", "Description": "Allow TCP"}]}]' |
Step 2: Create two EC2 instance that will act as a target for your Network load balancer.
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##-------------------------------------------------- ## Create two ec2 instances your nlb target group ## ##-------------------------------------------------- ## Get Amazon Linux 2 latest AMI ID AWS_AMI_ID=$(aws ec2 describe-images \ --owners 'amazon' \ --filters 'Name=name,Values=amzn2-ami-hvm-2.0.????????-x86_64-gp2' 'Name=state,Values=available' \ --query 'sort_by(Images, &CreationDate)[-1].[ImageId]' \ --output 'text') ## Create a key-pair aws ec2 create-key-pair \ --key-name myvpc-keypair \ --query 'KeyMaterial' \ --output text > myvpc-keypair.pem && chmod 400 myvpc-keypair.pem ## Create user data to configure LAMP stack vi myuserdataone.txt ----------------------- #!/bin/bash sudo yum install -y httpd sudo systemctl start httpd sudo usermod -a -G apache ec2-user sudo chown -R ec2-user:apache /var/www sudo chmod 2775 /var/www sudo find /var/www -type d -exec chmod 2775 {} \; sudo find /var/www -type f -exec chmod 0664 {} \; sudo echo "hello from instance one" > /var/www/html/index.html ----------------------- :wq vi myuserdatatwo.txt ----------------------- #!/bin/bash sudo yum install -y httpd sudo systemctl start httpd sudo usermod -a -G apache ec2-user sudo chown -R ec2-user:apache /var/www sudo chmod 2775 /var/www sudo find /var/www -type d -exec chmod 2775 {} \; sudo find /var/www -type f -exec chmod 0664 {} \; sudo echo "hello from instance two" > /var/www/html/index.html ----------------------- :wq ## Create two EC2 instance in two public subnet AWS_EC2_INSTANCE_ONE_ID=$(aws ec2 run-instances \ --image-id $AWS_AMI_ID \ --instance-type t2.micro \ --key-name myvpc-keypair \ --monitoring "Enabled=false" \ --security-group-ids $AWS_CUSTOM_SECURITY_GROUP_ID \ --subnet-id $AWS_SUBNET_PUBLIC_ONE_ID \ --user-data file://myuserdataone.txt \ --private-ip-address 10.0.1.10 \ --query 'Instances[0].InstanceId' \ --output text) && AWS_EC2_INSTANCE_TWO_ID=$(aws ec2 run-instances \ --image-id $AWS_AMI_ID \ --instance-type t2.micro \ --key-name myvpc-keypair \ --monitoring "Enabled=false" \ --security-group-ids $AWS_CUSTOM_SECURITY_GROUP_ID \ --subnet-id $AWS_SUBNET_PUBLIC_TWO_ID \ --user-data file://myuserdatatwo.txt \ --private-ip-address 10.0.2.10 \ --query 'Instances[0].InstanceId' \ --output text) |
Step 3: Create your Network Load Balancer
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##-------------------------------- ## Create network load balancer ## ##-------------------------------- ## Create the network load balancer AWS_NLB_ARN=$(aws elbv2 create-load-balancer \ --name my-network-load-balancer \ --subnets $AWS_SUBNET_PUBLIC_ONE_ID $AWS_SUBNET_PUBLIC_TWO_ID \ --type network \ --query 'LoadBalancers[0].LoadBalancerArn' \ --output text) ## Check the status of load balancer aws elbv2 describe-load-balancers \ --load-balancer-arns $AWS_NLB_ARN \ --query 'LoadBalancers[0].State.Code' \ --output text ## Once the nlb status is active, get the DNS name for your nlb AWS_NLB_DNS=$(aws elbv2 describe-load-balancers \ --load-balancer-arns $AWS_NLB_ARN \ --query 'LoadBalancers[0].DNSName' \ --output text) && echo $AWS_NLB_DNS ## Create the target group for your nlb AWS_NLB_TARGET_GROUP_ARN=$(aws elbv2 create-target-group \ --name my-nlb-targets \ --protocol TCP --port 80 \ --vpc-id $AWS_VPC_ID \ --query 'TargetGroups[0].TargetGroupArn' \ --output text) ## Register both the instances in the target group aws elbv2 register-targets --target-group-arn $AWS_NLB_TARGET_GROUP_ARN \ --targets Id=$AWS_EC2_INSTANCE_ONE_ID Id=$AWS_EC2_INSTANCE_TWO_ID ## Create a listener for your load balancer with a default rule that forwards requests to your target group AWS_NLB_LISTNER_ARN=$(aws elbv2 create-listener --load-balancer-arn $AWS_NLB_ARN \ --protocol TCP --port 80 \ --default-actions Type=forward,TargetGroupArn=$AWS_NLB_TARGET_GROUP_ARN \ --query 'Listeners[0].ListenerArn' \ --output text) ## Verify the health of the registered targets for your target group aws elbv2 describe-target-health --target-group-arn $AWS_NLB_TARGET_GROUP_ARN ## Open the DNS name of your NLB (below output) in your browser and hit refresh several time ## Or curl your NLB DNS name repetedly echo $AWS_NLB_DNS curl $AWS_NLB_DNS |
Observation: You will get response form both instance one and instance two as your curl/browser request is forwarded by NLB to target backends.
Step 4: Cleanup
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##----------- ## Cleanup ## ##----------- ## Delete the listener and Deregister targets aws elbv2 delete-listener \ --listener-arn $AWS_NLB_LISTNER_ARN && aws elbv2 deregister-targets \ --target-group-arn $AWS_NLB_TARGET_GROUP_ARN \ --targets Id=$AWS_EC2_INSTANCE_ONE_ID Id=$AWS_EC2_INSTANCE_TWO_ID ## Delete target group and nlb aws elbv2 delete-target-group \ --target-group-arn $AWS_NLB_TARGET_GROUP_ARN && aws elbv2 delete-load-balancer \ --load-balancer-arn $AWS_NLB_ARN ## Terminate the ec2 instances aws ec2 terminate-instances \ --instance-ids $AWS_EC2_INSTANCE_ONE_ID && aws ec2 terminate-instances \ --instance-ids $AWS_EC2_INSTANCE_TWO_ID ## Delete key pair aws ec2 delete-key-pair \ --key-name myvpc-keypair ## Delete custom security group (once instances are terminated) aws ec2 delete-security-group \ --group-id $AWS_CUSTOM_SECURITY_GROUP_ID ## Delete internet gateway aws ec2 detach-internet-gateway \ --internet-gateway-id $AWS_INTERNET_GATEWAY_ID \ --vpc-id $AWS_VPC_ID && aws ec2 delete-internet-gateway \ --internet-gateway-id $AWS_INTERNET_GATEWAY_ID ## Disassociate the subnets from custom route table aws ec2 disassociate-route-table \ --association-id $AWS_ROUTE_TABLE_ASSOID_ONE && aws ec2 disassociate-route-table \ --association-id $AWS_ROUTE_TABLE_ASSOID_TWO ## Delete custom route table aws ec2 delete-route-table \ --route-table-id $AWS_CUSTOM_ROUTE_TABLE_ID ## Delete the public subnets aws ec2 delete-subnet \ --subnet-id $AWS_SUBNET_PUBLIC_ONE_ID && aws ec2 delete-subnet \ --subnet-id $AWS_SUBNET_PUBLIC_TWO_ID ## Delete the vpc aws ec2 delete-vpc \ --vpc-id $AWS_VPC_ID ## Delete the directory used in this demo cd .. && rm -rf aws_nlb_demo |
Hope you have enjoyed this article, In the next blog post, we will discuss Target Groups in Network Load Balancer.
All the public cloud providers are changing the console user interface rapidly and due to this some of the screenshots used in our previous AWS blogs are no longer relevant. Hence, we have decided that from now onwards most of the demo will be done programmatically. Let us know your feedback on this in the comment section.
To get more details on AWS ELB, please refer below AWS documentation
https://docs.aws.amazon.com/elasticloadbalancing/index.html