Using Terraform to Auto Scale and Load Balance Compute Engine Instances in GCP

Learning how to configure complex environments with Terraform is a must-have skill. In this hands-on lab, we will provision an autoscaling group with a load balancer.

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Create a Service Account

From Google Cloud console’s main navigation, choose IAM & Admin > Service Accounts.
Click Create service account.
Give your service account a name.
Click Create.
In the roles dropdown, select Project > Owner.
Click Continue and then Done.

Log in to the Host Instance and Ensure Terraform Is Installed

From Google Cloud navigation, choose Compute Engine > VM instances.
Click SSH next to terraform-instance.
Use root privileges:
```
sudo -i
```
Change into the root directory:
```
cd /
```
Input the path to communicate with Terraform into the /etc/profile file:
```
echo "PATH='$PATH:/downloads/'" >> /etc/profile
```
Run the following in order to be able to call Terraform:
```
source /etc/profile
```
Call Terraform:
```
terraform
```

Create a Service Account Key within the Instance

Allow the SDK to communicate with GCP:
```
gcloud auth login
```
Enter Y at the prompt.
Click on the link in the output.
Select the Cloud Student account.
Click Allow.
Copy the code provided.
Paste the code into the terminal.

Create the service account key:

gcloud iam service-accounts keys create /downloads/auto-scaling.json --iam-account <SERVICE_ACCOUNT_EMAIL>

Create and Deploy the Configuration File

Create a main.tf file:
```
vim main.tf
```

Paste in the following, replacing all instances of <PROJECT_NAME> with your project name, which can be found in the top navigation bar of the Google Cloud console:

provider "google" {
  version = "3.20.0"

  credentials = file("/downloads/auto-scaling.json")

  project = "<PROJECT_NAME>"
  region  = "us-central1"
  zone    = "us-central1-c"
}

resource "google_compute_network" "vpc_network" {
  name = "new-terraform-network"
}
resource "google_compute_autoscaler" "foobar" {
  name   = "my-autoscaler"
  project = "<PROJECT_NAME>"
  zone   = "us-central1-c"
  target = google_compute_instance_group_manager.foobar.self_link

  autoscaling_policy {
    max_replicas    = 5
    min_replicas    = 2
    cooldown_period = 60

    cpu_utilization {
      target = 0.5
    }
  }
}

resource "google_compute_instance_template" "foobar" {
  name           = "my-instance-template"
  machine_type   = "n1-standard-1"
  can_ip_forward = false
  project = "<PROJECT_NAME>"
  tags = ["foo", "bar", "allow-lb-service"]

  disk {
    source_image = data.google_compute_image.centos_7.self_link
  }

  network_interface {
    network = google_compute_network.vpc_network.name
  }

  metadata = {
    foo = "bar"
  }

  service_account {
    scopes = ["userinfo-email", "compute-ro", "storage-ro"]
  }
}

resource "google_compute_target_pool" "foobar" {
  name = "my-target-pool"
  project = "<PROJECT_NAME>"
  region = "us-central1"
}

resource "google_compute_instance_group_manager" "foobar" {
  name = "my-igm"
  zone = "us-central1-c"
  project = "<PROJECT_NAME>"
  version {
    instance_template  = google_compute_instance_template.foobar.self_link
    name               = "primary"
  }

  target_pools       = [google_compute_target_pool.foobar.self_link]
  base_instance_name = "terraform"
}

data "google_compute_image" "centos_7" {
  family  = "centos-7"
  project = "centos-cloud"
}

module "lb" {
  source  = "GoogleCloudPlatform/lb/google"
  version = "2.2.0"
  region       = "us-central1"
  name         = "load-balancer"
  service_port = 80
  target_tags  = ["my-target-pool"]
  network      = google_compute_network.vpc_network.name
}

What are Hands-on Labs

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

Using Terraform to Auto Scale and Load Balance Compute Engine Instances in GCP

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Learning Objectives

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