Deploy Web Server on Google Compute Engine (GCE) with Terraform

In this blog, I will show how to deploy a Web Server (Nginx) using Terraform on Google Compute Engine(GCE). There are many ways to deploy Nginx server on GCP (like on GKE, App Engine, GCE etc.) but for this post I will use GCE to illustrate its usage.

The source code used in this blog is available here.

Photo

Goal

Deploy a Web Server on Google Compute Engine (GCE) using Terraform.

What we will explore?

  • Deploying a Google Compute VM Instance using Terraform.
  • Use of Compute Instance startup script.
  • Rendering a template in terraform.

Prerequisites

This post assumes the following:

  1. We already have a GCP Project with a network. By default, every GCP Project comes with a default network.
  2. Google Cloud SDK (gcloud) and Terraform is setup on your workstation. If you don’t have, then refer to my previous blogs - Getting started with Terraform and Getting started with Google Cloud SDK.

Create a Compute VM Instance

  1. Create a unix directory for the Terraform project.
mkdir ~/terraform-webserver
cd ~/terraform-webserver
  1. Define Terraform Google Provider.

    vi provider.tf
    

    This file has following content

    # Specify the GCP Provider
    provider "google" {
      project = var.project_id
      region  = var.region
    }
    
  2. Write below terraform code to create a Google Compute VM Instance.

    vi vm.tf
    

    To use the latest debian disk, we can use the data source

    data "google_compute_image" "debian" {
      family  = "ubuntu-1804-lts"
      project = "gce-uefi-images"
    }
    
    # Creates a GCP VM Instance.
    resource "google_compute_instance" "vm" {
      name         = var.name
      machine_type = var.machine_type
      zone         = var.zone
      tags         = ["http-server"]
      labels       = var.labels
    
      boot_disk {
        initialize_params {
          image = data.google_compute_image.debian.self_link
        }
      }
    
      network_interface {
        network = "default"
        access_config {
          // Ephemeral IP
        }
      }
    
      metadata_startup_script = data.template_file.nginx.rendered
    }
    

    Note: To allow HTTP connection to VM instance, we put http-server tag on the VM as tags = ["http-server"].

  3. Now, lets define a template file which has script to install Nginx server and create a simple webpage index.html

    mkdir template
    vi template/install_nginx.tpl
    
    #!/bin/bash
    set -e
    echo "*****    Installing Nginx    *****"
    apt update
    apt install -y nginx
    ufw allow '${ufw_allow_nginx}'
    systemctl enable nginx
    systemctl restart nginx
    
    echo "*****   Installation Complteted!!   *****"
    
    echo "Welcome to Google Compute VM Instance deployed using Terraform!!!" > /var/www/html
    
    echo "*****   Startup script completes!!    *****"
    

    Note: We pass the value of '${ufw_allow_nginx}' from terraform code during template rendering.

  4. Let’s, render the above template.

    vi vm.tf
    

    Append the following code.

    data "template_file" "nginx" {
      template = "${file("${path.module}/template/install_nginx.tpl")}"
    
      vars = {
        ufw_allow_nginx = "Nginx HTTP"
      }
    }
    
  5. Once the instance comes up, we want to know its public IP so that we can browse the webpage. To do this, we can use terraform outputs.

vi outputs.tf
output "webserver_ip" {
  value = google_compute_instance.vm.network_interface.0.access_config.0.nat_ip
}
  1. Now, define all the variables in a file.

    vi variables.tf
    
    variable "project_id" {
      description = "Google Cloud Platform (GCP) Project ID."
      type        = string
    }
    
    variable "region" {
      description = "GCP region name."
      type        = string
      default     = "europe-west1"
    }
    
    variable "zone" {
      description = "GCP zone name."
      type        = string
      default     = "europe-west1-b"
    }
    
    variable "name" {
      description = "Web server name."
      type        = string
      default     = "my-webserver"
    }
    
    variable "machine_type" {
      description = "GCP VM instance machine type."
      type        = string
      default     = "f1-micro"
    }
    
    variable "labels" {
      description = "List of labels to attach to the VM instance."
      type        = map
    }
    
  2. Define require variables value in tfvars file.

    vi terraform.tfvars
    
      project_id = "gcp-project-id"
      labels     = {
        "environment" = "test"
        "team"        = "devops"
        "application" = "webserver"
      }
    
  3. We now have all the required terraform configuration. So, let’s initialize the terraform project.

terraform init

Output

Initializing the backend...

Initializing provider plugins...
- Checking for available provider plugins...
- Downloading plugin for provider "google" (hashicorp/google) 3.4.0...
- Downloading plugin for provider "template" (hashicorp/template) 2.1.2...

The following providers do not have any version constraints in configuration,
so the latest version was installed.

To prevent automatic upgrades to new major versions that may contain breaking
changes, it is recommended to add version = "..." constraints to the
corresponding provider blocks in configuration, with the constraint strings
suggested below.

* provider.google: version = "~> 3.4"
* provider.template: version = "~> 2.1"

Terraform has been successfully initialized!

You may now begin working with Terraform. Try running "terraform plan" to see
any changes that are required for your infrastructure. All Terraform commands
should now work.

If you ever set or change modules or backend configuration for Terraform,
rerun this command to reinitialize your working directory. If you forget, other
commands will detect it and remind you to do so if necessary.
  ```

10. After successful initialization, run plan and save plan in a file.
```bash
terraform plan --out 1.plan

Output

Refreshing Terraform state in-memory prior to plan...
The refreshed state will be used to calculate this plan, but will not be
persisted to local or remote state storage.

data.template_file.nginx: Refreshing state...
data.google_compute_image.debian: Refreshing state...

------------------------------------------------------------------------

An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
  + create

Terraform will perform the following actions:

  # google_compute_instance.vm will be created
  + resource "google_compute_instance" "vm" {
      + can_ip_forward          = false
      + cpu_platform            = (known after apply)
      + deletion_protection     = false
      + guest_accelerator       = (known after apply)
      + id                      = (known after apply)
      + instance_id             = (known after apply)
      + label_fingerprint       = (known after apply)
      + labels                  = {
          + "application" = "webserver"
          + "environment" = "test"
          + "team"        = "devops"
        }
      + machine_type            = "f1-micro"
      + metadata_fingerprint    = (known after apply)
      + metadata_startup_script = "#!/bin/bash\nset -e\necho \"*****    Installing Nginx    *****\"\napt update\napt install -y nginx\nufw allow 'Nginx HTTP'\nsystemctl enable nginx\nsystemctl restart nginx\n \necho \"*****   Installation Complteted!!   *****\"\n \necho \"Welcome to Google Compute VM Instance deployed using Terraform!!!\" > /var/www/html/index.html\n \necho \"*****   Startup script completes!!    *****\"\n"
      + min_cpu_platform        = (known after apply)
      + name                    = "my-webserver"
      + project                 = (known after apply)
      + self_link               = (known after apply)
      + tags                    = [
          + "http-server",
        ]
      + tags_fingerprint        = (known after apply)
      + zone                    = "europe-west1-b"

      + boot_disk {
          + auto_delete                = true
          + device_name                = (known after apply)
          + disk_encryption_key_sha256 = (known after apply)
          + kms_key_self_link          = (known after apply)
          + mode                       = "READ_WRITE"
          + source                     = (known after apply)

          + initialize_params {
              + image  = "https://www.googleapis.com/compute/v1/projects/gce-uefi-images/global/images/ubuntu-1804-bionic-v20191113"
              + labels = (known after apply)
              + size   = (known after apply)
              + type   = (known after apply)
            }
        }

      + network_interface {
          + name               = (known after apply)
          + network            = "default"
          + network_ip         = (known after apply)
          + subnetwork         = (known after apply)
          + subnetwork_project = (known after apply)

          + access_config {
              + nat_ip       = (known after apply)
              + network_tier = (known after apply)
            }
        }

      + scheduling {
          + automatic_restart   = (known after apply)
          + on_host_maintenance = (known after apply)
          + preemptible         = (known after apply)

          + node_affinities {
              + key      = (known after apply)
              + operator = (known after apply)
              + values   = (known after apply)
            }
        }
    }

Plan: 1 to add, 0 to change, 0 to destroy.

------------------------------------------------------------------------

This plan was saved to: 1.plan

To perform exactly these actions, run the following command to apply:
    terraform apply "1.plan"
  ```

11. Plan shows to create a VM instance and use `install_nginx.tpl` as startup script. So, let's go ahead and apply the plan.
```bash
terraform apply 1.plan

Output

google_compute_instance.vm: Creating...
google_compute_instance.vm: Still creating... [10s elapsed]
google_compute_instance.vm: Creation complete after 15s [id=projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver]

Apply complete! Resources: 1 added, 0 changed, 0 destroyed.

The state of your infrastructure has been saved to the path
below. This state is required to modify and destroy your
infrastructure, so keep it safe. To inspect the complete state
use the `terraform show` command.

State path: terraform.tfstate

Outputs:

webserver_ip = 35.240.104.9
  1. Now if you navigate to Google Console and navigate to Compute Engine --> VM Instance, you will see an instance coming up. Once the instance is up successfully, browse the webserver_ip. In this case, go to http://35.240.104.9 Photo

  2. For cleanup, run terraform destroy.

terraform destroy

Output

data.template_file.nginx: Refreshing state...
data.google_compute_image.debian: Refreshing state...
google_compute_instance.vm: Refreshing state... [id=projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver]

An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
  - destroy

Terraform will perform the following actions:

  # google_compute_instance.vm will be destroyed
  - resource "google_compute_instance" "vm" {
      - can_ip_forward          = false -> null
      - cpu_platform            = "Intel Haswell" -> null
      - deletion_protection     = false -> null
      - enable_display          = false -> null
      - guest_accelerator       = [] -> null
      - id                      = "projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver" -> null
      - instance_id             = "3519528545052665512" -> null
      - label_fingerprint       = "k3pYoTAUZq4=" -> null
      - labels                  = {
          - "application" = "webserver"
          - "environment" = "test"
          - "team"        = "devops"
        } -> null
      - machine_type            = "f1-micro" -> null
      - metadata                = {} -> null
      - metadata_fingerprint    = "mE2Cwt2znPk=" -> null
      - metadata_startup_script = "#!/bin/bash\nset -e\necho \"*****    Installing Nginx    *****\"\napt update\napt install -y nginx\nufw allow 'Nginx HTTP'\nsystemctl enable nginx\nsystemctl restart nginx\n\necho \"*****   Installation Complteted!!   *****\"\n\necho \"Welcome to Google Compute VM Instance deployed using Terraform!!!\" > /var/www/html/index.html\n\necho \"*****   Startup script completes!!    *****\"\n" -> null
      - name                    = "my-webserver" -> null
      - project                 = "workshop-demo-34293" -> null
      - self_link               = "https://www.googleapis.com/compute/v1/projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver" -> null
      - tags                    = [
          - "http-server",
        ] -> null
      - tags_fingerprint        = "FYLDgkTKlA4=" -> null
      - zone                    = "europe-west1-b" -> null

      - boot_disk {
          - auto_delete = true -> null
          - device_name = "persistent-disk-0" -> null
          - mode        = "READ_WRITE" -> null
          - source      = "https://www.googleapis.com/compute/v1/projects/workshop-demo-34293/zones/europe-west1-b/disks/my-webserver" -> null

          - initialize_params {
              - image  = "https://www.googleapis.com/compute/v1/projects/gce-uefi-images/global/images/ubuntu-1804-bionic-v20191113" -> null
              - labels = {} -> null
              - size   = 10 -> null
              - type   = "pd-standard" -> null
            }
        }

      - network_interface {
          - name               = "nic0" -> null
          - network            = "https://www.googleapis.com/compute/v1/projects/workshop-demo-34293/global/networks/default" -> null
          - network_ip         = "10.132.0.13" -> null
          - subnetwork         = "https://www.googleapis.com/compute/v1/projects/workshop-demo-34293/regions/europe-west1/subnetworks/default" -> null
          - subnetwork_project = "workshop-demo-34293" -> null

          - access_config {
              - nat_ip       = "35.240.104.9" -> null
              - network_tier = "PREMIUM" -> null
            }
        }

      - scheduling {
          - automatic_restart   = true -> null
          - on_host_maintenance = "MIGRATE" -> null
          - preemptible         = false -> null
        }

      - shielded_instance_config {
          - enable_integrity_monitoring = true -> null
          - enable_secure_boot          = false -> null
          - enable_vtpm                 = true -> null
        }
    }

Plan: 0 to add, 0 to change, 1 to destroy.

Do you really want to destroy all resources?
  Terraform will destroy all your managed infrastructure, as shown above.
  There is no undo. Only 'yes' will be accepted to confirm.

  Enter a value: yes

google_compute_instance.vm: Destroying... [id=projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver]
google_compute_instance.vm: Still destroying... [id=projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver, 10s elapsed]
google_compute_instance.vm: Still destroying... [id=projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver, 20s elapsed]

google_compute_instance.vm: Still destroying... [id=projects/workshop-demo-34293/zones/europe-west1-b/instances/my-webserver, 2m30s elapsed]
google_compute_instance.vm: Destruction complete after 2m36s

Destroy complete! Resources: 1 destroyed.

Hope this blog gives you familiarity with google_compute_instance and Terraform template rendering.

If you have feedback or questions, please reach out to me on LinkedIn or Twitter