Create an Internal Load Balancer UPDATED CONTENT

[bhaireshm]

#!/bin/bash

Variables

PROJECT_ID=$(gcloud config get-value project)
REGION="us-west1"
ZONE_1="${REGION}-c"
ZONE_2="${REGION}-b" # You may need to adjust this if a different zone is specified
NETWORK="my-internal-app"
SUBNET_A="subnet-a"
SUBNET_B="subnet-b"

Function to check if a resource is ready

check_resource() {
local resource_type=$1
local resource_name=$2
local max_attempts=10
local attempt=1

while [ $attempt -le $max_attempts ]; do
    if gcloud $resource_type describe $resource_name --quiet >/dev/null 2>&1; then
        echo "$resource_type $resource_name is ready."
        return 0
    fi
    echo "Waiting for $resource_type $resource_name to be ready... (Attempt $attempt/$max_attempts)"
    sleep 10
    ((attempt++))
done

echo "Timeout waiting for $resource_type $resource_name to be ready."
return 1

}

Create internal IP address

echo "Creating internal IP address..."
gcloud compute addresses create my-ilb-ip
--region=$REGION
--subnet=$SUBNET_B
--addresses=10.10.30.5

check_resource "compute addresses" "my-ilb-ip --region=$REGION"

Create forwarding rule

echo "Creating forwarding rule..."
gcloud compute forwarding-rules create my-ilb-forwarding-rule
--load-balancing-scheme=internal
--network=$NETWORK
--subnet=$SUBNET_B
--address=my-ilb-ip
--ports=80
--region=$REGION
--backend-service=my-ilb-backend-service

check_resource "compute forwarding-rules" "my-ilb-forwarding-rule --region=$REGION"

sleep 10 # Wait for firewall rule to propagate

Create instance templates

echo "Creating instance template 1..."
gcloud compute instance-templates create instance-template-1
--machine-type=e2-medium
--network=$NETWORK
--subnet=$SUBNET_A
--tags=lb-backend
--metadata=startup-script-url=gs://cloud-training/gcpnet/ilb/startup.sh
--region=$REGION

echo "Creating instance template 2..."
gcloud compute instance-templates create instance-template-2
--machine-type=e2-medium
--network=$NETWORK
--subnet=$SUBNET_B
--tags=lb-backend
--metadata=startup-script-url=gs://cloud-training/gcpnet/ilb/startup.sh
--region=$REGION

sleep 20 # Wait for instance templates to be fully created

Create managed instance groups

echo "Creating managed instance group 1..."
gcloud compute instance-groups managed create instance-group-1
--template=instance-template-1
--size=1
--zone=$ZONE_1

echo "Creating managed instance group 2..."
gcloud compute instance-groups managed create instance-group-2
--template=instance-template-2
--size=1
--zone=$ZONE_2

sleep 60 # Wait for instances to be created and initialized

Configure autoscaling for instance groups

echo "Configuring autoscaling for instance group 1..."
gcloud compute instance-groups managed set-autoscaling instance-group-1
--max-num-replicas=5
--target-cpu-utilization=0.8
--cool-down-period=45
--zone=$ZONE_1

echo "Configuring autoscaling for instance group 2..."
gcloud compute instance-groups managed set-autoscaling instance-group-2
--max-num-replicas=5
--target-cpu-utilization=0.8
--cool-down-period=45
--zone=$ZONE_2

sleep 30 # Wait for autoscaling to be configured

Create utility VM

echo "Creating utility VM..."
gcloud compute instances create utility-vm
--zone=$ZONE_1
--machine-type=e2-micro
--network=$NETWORK
--subnet=$SUBNET_A
--private-network-ip=10.10.20.50

check_resource "compute instances" "utility-vm --zone=$ZONE_1"

Create health check

echo "Creating health check..."
gcloud compute health-checks create tcp my-ilb-health-check
--port=80
--region=$REGION

sleep 10 # Wait for health check to be created

Create backend service

echo "Creating backend service..."
gcloud compute backend-services create my-ilb-backend-service
--load-balancing-scheme=internal
--protocol=tcp
--region=$REGION
--health-checks=my-ilb-health-check
--health-checks-region=$REGION

check_resource "compute backend-services" "my-ilb-backend-service --region=$REGION"

Add instance groups to backend service

echo "Adding instance groups to backend service..."
gcloud compute backend-services add-backend my-ilb-backend-service
--instance-group=instance-group-1
--instance-group-zone=$ZONE_1
--region=$REGION

gcloud compute backend-services add-backend my-ilb-backend-service
--instance-group=instance-group-2
--instance-group-zone=$ZONE_2
--region=$REGION

sleep 30 # Wait for backends to be added

Create internal IP address

echo "Creating internal IP address..."
gcloud compute addresses create my-ilb-ip
--region=$REGION
--subnet=$SUBNET_B
--addresses=10.10.30.5

check_resource "compute addresses" "my-ilb-ip --region=$REGION"

Create forwarding rule

echo "Creating forwarding rule..."
gcloud compute forwarding-rules create my-ilb-forwarding-rule
--load-balancing-scheme=internal
--network=$NETWORK
--subnet=$SUBNET_B
--address=my-ilb-ip
--ports=80
--region=$REGION
--backend-service=my-ilb-backend-service

check_resource "compute forwarding-rules" "my-ilb-forwarding-rule --region=$REGION"

echo "Setup complete!"