Fix: derive project id for instance from instance template (#63)

* get project id from instance template selflink

* pass subnet selflink instead of name fixture

Author: bharathkkb

examples/compute_instance/simple/README.md

@@ -11,7 +11,7 @@ This is a simple, minimal example of how to use the compute_instance module
 | project\_id | The GCP project to use for integration tests | string | n/a | yes |
 | region | The GCP region to create and test resources in | string | `"us-central1"` | no |
 | service\_account | Service account to attach to the instance. See https://www.terraform.io/docs/providers/google/r/compute_instance_template.html#service_account. | object | `"null"` | no |
-| subnetwork | The subnetwork to host the compute instances in | string | n/a | yes |
+| subnetwork | The subnetwork selflink to host the compute instances in | string | n/a | yes |
 
 ## Outputs
 

examples/compute_instance/simple/main.tf

@@ -16,13 +16,13 @@
 
 provider "google" {
 
-  project = var.project_id
   version = "~> 2.7.0"
 }
 
 module "instance_template" {
   source          = "../../../modules/instance_template"
   region          = var.region
+  project_id      = var.project_id
   subnetwork      = var.subnetwork
   service_account = var.service_account
 }

examples/compute_instance/simple/variables.tf

@@ -28,7 +28,7 @@ variable "region" {
 }
 
 variable "subnetwork" {
-  description = "The subnetwork to host the compute instances in"
+  description = "The subnetwork selflink to host the compute instances in"
 }
 
 variable "num_instances" {

modules/compute_instance/main.tf

@@ -22,14 +22,16 @@ locals {
   # at the end of the list to work around "list does not have any elements so cannot
   # determine type" error when var.static_ips is empty
   static_ips = concat(var.static_ips, ["NOT_AN_IP"])
+  project_id = length(regexall("/projects/([^/]*)", var.instance_template)) > 0 ? flatten(regexall("/projects/([^/]*)", var.instance_template))[0] : null
 }
 
 ###############
 # Data Sources
 ###############
 
 data "google_compute_zones" "available" {
-  region = var.region
+  project = local.project_id
+  region  = var.region
 }
 
 #############
@@ -40,6 +42,7 @@ resource "google_compute_instance_from_template" "compute_instance" {
   provider = google
   count    = local.num_instances
   name     = "${local.hostname}-${format("%03d", count.index + 1)}"
+  project  = local.project_id
   zone     = data.google_compute_zones.available.names[count.index % length(data.google_compute_zones.available.names)]
 
   network_interface {

test/fixtures/compute_instance/simple/main.tf

@@ -19,7 +19,7 @@ module "instance_simple" {
   source          = "../../../../examples/compute_instance/simple"
   project_id      = var.project_id
   region          = "us-central1"
-  subnetwork      = google_compute_subnetwork.main.name
+  subnetwork      = google_compute_subnetwork.main.self_link
   num_instances   = 4
   service_account = var.service_account
 }