Add Cloud Build for GCP CI env

Author: roger2hk

deployment/modules/gcp/cloudbuild/main.tf

@@ -70,6 +70,12 @@ resource "google_project_iam_member" "run_developer" {
   member  = "serviceAccount:${google_service_account.cloudbuild_service_account.email}"
 }
 
+resource "google_project_iam_member" "iam_service_account_user" {
+  project = var.project_id
+  role    = "roles/iam.serviceAccountUser"
+  member  = "serviceAccount:${google_service_account.cloudbuild_service_account.email}"
+}
+
 resource "google_cloudbuild_trigger" "build_trigger" {
   name            = "build-docker-${var.env}"
   service_account = google_service_account.cloudbuild_service_account.id