Add CDN load balancer with Cloud Storage buckets as backend (#5575) (#10975)

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/5575.txt

@@ -0,0 +1,2 @@
+```release-note:none
+```

website/docs/r/compute_global_forwarding_rule.html.markdown

@@ -32,6 +32,151 @@ https://cloud.google.com/compute/docs/load-balancing/http/
 
 
 
+<div class = "oics-button" style="float: right; margin: 0 0 -15px">
+  <a href="https://console.cloud.google.com/cloudshell/open?cloudshell_git_repo=https%3A%2F%2Fgithub.jpy.wang%2Fterraform-google-modules%2Fdocs-examples.git&cloudshell_working_dir=external_cnd_lb_with_backend_bucket&cloudshell_image=gcr.io%2Fgraphite-cloud-shell-images%2Fterraform%3Alatest&open_in_editor=main.tf&cloudshell_print=.%2Fmotd&cloudshell_tutorial=.%2Ftutorial.md" target="_blank">
+    <img alt="Open in Cloud Shell" src="//gstatic.com/cloudssh/images/open-btn.svg" style="max-height: 44px; margin: 32px auto; max-width: 100%;">
+  </a>
+</div>
+## Example Usage - External Cnd Lb With Backend Bucket
+
+
+```hcl
+# CDN load balancer with Cloud bucket as backend
+
+# VPC
+resource "google_compute_network" "default" {
+  name                    = "cdn-network"
+  provider                = google-beta
+  auto_create_subnetworks = false
+}
+
+# backend subnet
+resource "google_compute_subnetwork" "default" {
+  name          = "cdn-subnet"
+  provider      = google-beta
+  ip_cidr_range = "10.0.1.0/24"
+  region        = "us-central1"
+  network       = google_compute_network.default.id
+}
+
+# reserve IP address
+resource "google_compute_global_address" "default" {
+  provider = google-beta
+  name     = "cdn-static-ip"
+}
+
+# forwarding rule
+resource "google_compute_global_forwarding_rule" "default" {
+  name                  = "cdn-forwarding-rule"
+  provider              = google-beta
+  ip_protocol           = "TCP"
+  load_balancing_scheme = "EXTERNAL"
+  port_range            = "80"
+  target                = google_compute_target_http_proxy.default.id
+  ip_address            = google_compute_global_address.default.id
+}
+
+# http proxy
+resource "google_compute_target_http_proxy" "default" {
+  name     = "cdn-target-http-proxy"
+  provider = google-beta
+  url_map  = google_compute_url_map.default.id
+}
+
+# url map
+resource "google_compute_url_map" "default" {
+  name            = "cdn-url-map"
+  provider        = google-beta
+  default_service = google_compute_backend_bucket.default.id
+}
+
+# backend bucket with CDN policy with default ttl settings
+resource "google_compute_backend_bucket" "default" {
+  name        = "image-backend-bucket"
+  description = "Contains beautiful images"
+  bucket_name = google_storage_bucket.default.name
+  enable_cdn  = true
+  cdn_policy {
+    cache_mode        = "CACHE_ALL_STATIC"
+    client_ttl        = 3600
+    default_ttl       = 3600
+    max_ttl           = 86400
+    negative_caching  = true
+    serve_while_stale = 86400
+  }
+}
+
+# cdn backend bucket
+resource "google_storage_bucket" "default" {
+  name                        = "cdn-backend-storage-bucket"
+  location                    = "US"
+  uniform_bucket_level_access = true
+  // delete bucket and contents on destroy.
+  force_destroy = true
+  // Assign specialty files
+  website {
+    main_page_suffix = "index.html"
+    not_found_page   = "404.html"
+  }
+}
+
+# make bucket public
+resource "google_storage_bucket_iam_member" "default" {
+  bucket = google_storage_bucket.default.name
+  role   = "roles/storage.objectViewer"
+  member = "allUsers"
+}
+
+resource "google_storage_bucket_object" "index_page" {
+  name       = "index.html"
+  source     = "index.html"
+  bucket     = google_storage_bucket.default.name
+  depends_on = [local_file.index_page]
+}
+
+resource "google_storage_bucket_object" "error_page" {
+  name       = "404.html"
+  source     = "404.html"
+  bucket     = google_storage_bucket.default.name
+  depends_on = [local_file.error_page]
+}
+
+# image object for testing, try to access http://<your_lb_ip_address>/test.jpg
+resource "google_storage_bucket_object" "test_image" {
+  name         = "test.jpg"
+  source       = "test.jpg"
+  content_type = "image/jpeg"
+  bucket       = google_storage_bucket.default.name
+  depends_on   = [null_resource.test_image]
+}
+
+# cdn sample index page
+resource "local_file" "index_page" {
+  filename = "index.html"
+  content  = <<-EOT
+    <html><body>
+    <h1>Congratulations on setting up Google Cloud CDN with Storage backend!</h1>
+    </body></html>
+  EOT
+}
+
+# cdn default error page
+resource "local_file" "error_page" {
+  filename = "404.html"
+  content  = <<-EOT
+    <html><body>
+    <h1>404 Error: Object you are looking for is no longer available!</h1>
+    </body></html>
+  EOT
+}
+
+# cdn sample image
+resource "null_resource" "test_image" {
+  provisioner "local-exec" {
+    command = "wget -O test.jpg  https://upload.wikimedia.org/wikipedia/commons/c/c8/Thank_you_001.jpg"
+  }
+}
+```
 ## Example Usage - External Ssl Proxy Lb Mig Backend