don't include IGM URLs that 404 in instance_group_urls (#3438)

third_party/terraform/resources/resource_container_cluster.go.erb

@@ -2172,6 +2172,10 @@ func getInstanceGroupUrlsFromManagerUrls(config *Config, igmUrls []string) ([]st
 		}
 		matches := instanceGroupManagerURL.FindStringSubmatch(u)
 		instanceGroupManager, err := config.clientCompute.InstanceGroupManagers.Get(matches[1], matches[2], matches[3]).Do()
+		if isGoogleApiErrorWithCode(err, 404) {
+			// The IGM URL is stale; don't include it
+			continue
+		}
 		if err != nil {
 			return nil, fmt.Errorf("Error reading instance group manager returned as an instance group URL: %s", err)
 		}

third_party/terraform/resources/resource_container_node_pool.go.erb

@@ -561,17 +561,27 @@ func flattenNodePool(d *schema.ResourceData, config *Config, np *containerBeta.N
 	// instance groups instead. They should all have the same size, but in case a resize
 	// failed or something else strange happened, we'll just use the average size.
 	size := 0
+	igmUrls := []string{}
 	for _, url := range np.InstanceGroupUrls {
 		// retrieve instance group manager (InstanceGroupUrls are actually URLs for InstanceGroupManagers)
 		matches := instanceGroupManagerURL.FindStringSubmatch(url)
 		if len(matches) < 4 {
 			return nil, fmt.Errorf("Error reading instance group manage URL '%q'", url)
 		}
 		igm, err := config.clientComputeBeta.InstanceGroupManagers.Get(matches[1], matches[2], matches[3]).Do()
+		if isGoogleApiErrorWithCode(err, 404) {
+			// The IGM URL in is stale; don't include it
+			continue
+		}
 		if err != nil {
 			return nil, fmt.Errorf("Error reading instance group manager returned as an instance group URL: %q", err)
 		}
 		size += int(igm.TargetSize)
+		igmUrls = append(igmUrls, url)
+	}
+	nodeCount := 0
+	if len(igmUrls) > 0 {
+		nodeCount = size / len(igmUrls)
 	}
 	nodePool := map[string]interface{}{
 		"name":                np.Name,
@@ -580,9 +590,9 @@ func flattenNodePool(d *schema.ResourceData, config *Config, np *containerBeta.N
 <% unless version == 'ga' -%>
 		"node_locations":      schema.NewSet(schema.HashString, convertStringArrToInterface(np.Locations)),
 <% end -%>
-		"node_count":          size / len(np.InstanceGroupUrls),
+		"node_count":          nodeCount,
 		"node_config":         flattenNodeConfig(np.Config),
-		"instance_group_urls": np.InstanceGroupUrls,
+		"instance_group_urls": igmUrls,
 		"version":             np.Version,
 	}