Handle GKE cluster client cert settings correctly

google/resource_container_cluster.go

@@ -342,19 +342,22 @@ func resourceContainerCluster() *schema.Resource {
 							Optional: true,
 						},
 
+						// Ideally, this would be Optional (and not Computed).
+						// In past versions (incl. 2.X series) of the provider
+						// though, being unset was considered identical to set
+						// and the issue_client_certificate value being true.
 						"client_certificate_config": {
-							Type:             schema.TypeList,
-							MaxItems:         1,
-							Optional:         true,
-							DiffSuppressFunc: masterAuthClientCertCfgSuppress,
-							ForceNew:         true,
+							Type:     schema.TypeList,
+							MaxItems: 1,
+							Optional: true,
+							Computed: true,
+							ForceNew: true,
 							Elem: &schema.Resource{
 								Schema: map[string]*schema.Schema{
 									"issue_client_certificate": {
-										Type:             schema.TypeBool,
-										Required:         true,
-										ForceNew:         true,
-										DiffSuppressFunc: masterAuthClientCertCfgSuppress,
+										Type:     schema.TypeBool,
+										Required: true,
+										ForceNew: true,
 									},
 								},
 							},
@@ -1660,16 +1663,17 @@ func expandMasterAuth(configured interface{}) *containerBeta.MasterAuth {
 		Username: masterAuth["username"].(string),
 		Password: masterAuth["password"].(string),
 	}
-	if _, ok := masterAuth["client_certificate_config"]; ok {
-		if len(masterAuth["client_certificate_config"].([]interface{})) > 0 {
+
+	if v, ok := masterAuth["client_certificate_config"]; ok {
+		if len(v.([]interface{})) > 0 {
 			clientCertificateConfig := masterAuth["client_certificate_config"].([]interface{})[0].(map[string]interface{})
-			if _, ok := clientCertificateConfig["issue_client_certificate"]; ok {
-				result.ClientCertificateConfig = &containerBeta.ClientCertificateConfig{
-					IssueClientCertificate: clientCertificateConfig["issue_client_certificate"].(bool),
-				}
+
+			result.ClientCertificateConfig = &containerBeta.ClientCertificateConfig{
+				IssueClientCertificate: clientCertificateConfig["issue_client_certificate"].(bool),
 			}
 		}
 	}
+
 	return result
 }
 
@@ -1879,11 +1883,18 @@ func flattenMasterAuth(ma *containerBeta.MasterAuth) []map[string]interface{} {
 			"cluster_ca_certificate": ma.ClusterCaCertificate,
 		},
 	}
-	if len(ma.ClientCertificate) == 0 {
-		masterAuth[0]["client_certificate_config"] = []map[string]interface{}{
-			{"issue_client_certificate": false},
-		}
+
+	// No version of the GKE API returns the client_certificate_config value.
+	// Instead, we need to infer whether or not it was set based on the
+	// client cert being returned from the API or not.
+	// Previous versions of the provider didn't record anything in state when
+	// a client cert was enabled, only setting the block when it was false.
+	masterAuth[0]["client_certificate_config"] = []map[string]interface{}{
+		{
+			"issue_client_certificate": len(ma.ClientCertificate) != 0,
+		},
 	}
+
 	return masterAuth
 }
 
@@ -1975,30 +1986,6 @@ func cidrOrSizeDiffSuppress(k, old, new string, d *schema.ResourceData) bool {
 	return strings.HasPrefix(new, "/") && strings.HasSuffix(old, new)
 }
 
-// We want to suppress diffs for empty or default client certificate configs, i.e:
-// 	[{ "issue_client_certificate": true}] --> []
-//  [] -> [{ "issue_client_certificate": true}]
-func masterAuthClientCertCfgSuppress(k, old, new string, r *schema.ResourceData) bool {
-	var clientConfig map[string]interface{}
-	if v, ok := r.GetOk("master_auth"); ok {
-		masterAuths := v.([]interface{})
-		masterAuth := masterAuths[0].(map[string]interface{})
-		cfgs := masterAuth["client_certificate_config"].([]interface{})
-		if len(cfgs) > 0 {
-			clientConfig = cfgs[0].(map[string]interface{})
-		}
-	}
-
-	if strings.HasSuffix(k, "client_certificate_config.#") && old == "0" && new == "1" {
-		// nil --> { "issue_client_certificate": true }
-		if issueCert, ok := clientConfig["issue_client_certificate"]; ok {
-			return issueCert.(bool)
-		}
-	}
-
-	return strings.HasSuffix(k, ".issue_client_certificate") && old == "" && new == "true"
-}
-
 // We want to suppress diffs for empty/disabled private cluster config.
 func containerClusterPrivateClusterConfigSuppress(k, old, new string, d *schema.ResourceData) bool {
 	o, n := d.GetChange("private_cluster_config.0.enable_private_endpoint")

website/docs/getting_started.html.markdown

@@ -81,7 +81,7 @@ resource "google_compute_instance" "vm_instance" {
   network_interface {
     # A default network is created for all GCP projects
     network       = "default"
-    access_config = {
+    access_config {
     }
   }
 }
@@ -135,7 +135,7 @@ network_interface {
 -  # A default network is created for all GCP projects
 -  network = "default"
 +  network = "${google_compute_network.vpc_network.self_link}"
-  access_config = {
+  access_config {
 ```
 
 This means that when we create the VM instance, it will use
@@ -190,7 +190,7 @@ resource "google_compute_instance" "vm_instance" {
   network_interface {
     # A default network is created for all GCP projects
     network       = "${google_compute_network.vpc_network.self_link}"
-    access_config = {
+    access_config {
     }
   }
 }