How to add the `default-allow-http` - google-cloud-platform

Question

How to add the default-allow-http firewall rule in a terraform script to a Google Cloud Compute Instance?
provider "google" {
credentials = file("CREDENTIAL_FILE")
project = "gitlab-project"
region = var.region
}
resource "google_compute_instance" "gitlab" {
name = var.machine_specs.name
machine_type = var.machine_type.emicro
zone = var.zone
boot_disk {
initialize_params {
image = var.machine_specs.os
size = var.machine_specs.size
}
}
network_interface {
# A default network is created for all GCP projects
network = "default"
access_config {
nat_ip = google_compute_address.static.address
}
}
// Add the SSH key
metadata = {
ssh-keys = "martin:${file("~/.ssh/id_rsa.pub")}"
}
}
// A variable for extracting the external ip of the instance
output "ip" {
value = "${google_compute_instance.gitlab.network_interface.0.access_config.0.nat_ip}"
}
resource "google_compute_address" "static" {
name = "ipv4-address"
address_type = "EXTERNAL"
address = "XXX.XXX.XXX.XXX"
}
resource "google_compute_firewall" "allow-http" {
name = "default-allow-http"
network =
allow{
protocol = "tcp"
ports = ["80"]
}
}

Answer 1

You can use tags argument available in google_compute_instance resource.
it would look something like:
resource "google_compute_instance" "gitlab" {
name = var.machine_specs.name
machine_type = var.machine_type.emicro
zone = var.zone
tags = ["http-server"]
http-server tag is for default-allow-http firewall rule.
If you need default-allow-https then simply append https-server to the tag list.
Hope this helps.

Answer 2

You need to add the tags ["http-server", "https-server"] to your resource group google_compute_instance like so:
[...]
resource "google_compute_instance" "gitlab" {
name = var.machine_specs.name
machine_type = var.machine_type.emicro
zone = var.zone
tags = ["http-server", "https-server"]
[...]

Answer 3

Simply add the tags http-server and https-server to your google_cloud_instance resource gruop.
The tags can be found in the Firewall-settings in your GCloud-Console.