Add Terraform for Google Cloud Build Triggers (kubernetes#193)

* Add .gitignore with Terraform-related files

* Add Terraform for Google Cloud Build Triggers

* Store Terraform state in Google Cloud Storage

.gitignore

@@ -0,0 +1,4 @@
+# Terraform
+**/.terraform/*
+*.tfstate
+*.tfstate.*

terraform/google-cloud-build-triggers.tf

@@ -0,0 +1,177 @@
+// Some of the Docker images from this repository are stored in Google Cloud's Artifact Registry (e.g., images referenced by GKE tutorials).
+// Such images are rebuilt and repushed to Artifact Registry whenever related changes occur.
+// The rebuilding/repushing is done by Google Cloud Build Triggers that we have set up in the "google-samples" Google Cloud project.
+// This .tf file describes those Google Cloud Build Triggers and can be used to recreate them (e.g., in case they're accidentally deleted).
+// How to use this file:
+//     1. Install Terraform.
+//     2. From this directory, run "terraform init". This will download the Google Terraform plugin.
+//        If you get an error similar to "querying Cloud Storage failed: storage: bucket doesn't exist",
+//        try running: gcloud auth application-default login
+//     3. Finally, run "terraform apply" to create any missing Google Cloud Build Triggers.
+
+terraform {
+  backend "gcs" {
+    bucket = "kubernetes-engine-samples"
+    prefix = "terraform-state"
+  }
+}
+
+provider "google" {
+    project = "google-samples"
+    region = "us-central1"
+    zone = "us-central1-b"
+}
+
+locals {
+    trigger_description = "This Cloud Build Trigger was created using Terraform (see github.com/GoogleCloudPlatform/kubernetes-engine-samples/tree/master/terraform)."
+}
+
+resource "google_cloudbuild_trigger" "cloud-pubsub" {
+    name = "kubernetes-engine-samples-cloud-pubsub"
+    filename = "cloud-pubsub/cloudbuild.yaml"
+    included_files = ["cloud-pubsub/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "custom-metrics-direct-to-sd" {
+    name = "kubernetes-engine-samples-custom-metrics-direct-to-sd"
+    filename = "custom-metrics-autoscaling/direct-to-sd/cloudbuild.yaml"
+    included_files = ["custom-metrics-autoscaling/direct-to-sd/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "custom-metrics-prometheus-to-sd" {
+    name = "kubernetes-engine-samples-custom-metrics-prometheus-to-sd"
+    description = local.trigger_description
+    filename = "custom-metrics-autoscaling/prometheus-to-sd/cloudbuild.yaml"
+    included_files = ["custom-metrics-autoscaling/prometheus-to-sd/**"]
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "guestbook-php-redis" {
+    name = "kubernetes-engine-samples-guestbook-php-redis"
+    filename = "guestbook/php-redis/cloudbuild.yaml"
+    included_files = ["guestbook/php-redis/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "guestbook-redis-follower" {
+    name = "kubernetes-engine-samples-guestbook-redis-follower"
+    filename = "guestbook/redis-follower/cloudbuild.yaml"
+    included_files = ["guestbook/redis-follower/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "hello-app" {
+    name = "kubernetes-engine-samples-hello-app"
+    filename = "hello-app/cloudbuild.yaml"
+    included_files = ["hello-app/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "hello-app-cdn" {
+    name = "kubernetes-engine-samples-hello-app-cdn"
+    filename = "hello-app-cdn/cloudbuild.yaml"
+    included_files = ["hello-app-cdn/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "hello-app-redis" {
+    name = "kubernetes-engine-samples-hello-app-redis"
+    filename = "hello-app-redis/cloudbuild.yaml"
+    included_files = ["hello-app-redis/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "hello-app-tls" {
+    name = "kubernetes-engine-samples-hello-app-tls"
+    filename = "hello-app-tls/cloudbuild.yaml"
+    included_files = ["hello-app-tls/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}
+
+resource "google_cloudbuild_trigger" "whereami" {
+    name = "kubernetes-engine-samples-whereami"
+    filename = "whereami/cloudbuild.yaml"
+    included_files = ["whereami/**"]
+    description = local.trigger_description
+
+    github {
+        owner = "GoogleCloudPlatform"
+        name = "kubernetes-engine-samples"
+        push {
+            branch = "^master$"
+        }
+    }
+}