Handle invalid kubeconfig context (#960)

Rather than immediately returning an error for an invalid kubeconfig
context, mark the cluster as unreachable, and only fail with an error
on operations that need to talk to the cluster. This will allow invoke
methods to operate using the default provider even if no local cluster
is configured.

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## HEAD (Unreleased)
 
+### Bug fixes
+
+-   Handle invalid kubeconfig context. (https://github.com/pulumi/pulumi-kubernetes/pull/960).
+
 ## 1.4.4 (January 21, 2020)
 
 ### Improvements

pkg/provider/provider.go

@@ -107,8 +107,10 @@ type kubeProvider struct {
 	suppressDeprecationWarnings bool
 	enableSecrets               bool
 
-	clusterUnreachable bool         // Kubernetes cluster is unreachable
-	config             *rest.Config // Cluster config, e.g., through $KUBECONFIG file.
+	clusterUnreachable       bool   // Kubernetes cluster is unreachable.
+	clusterUnreachableReason string // Detailed error message if cluster is unreachable.
+
+	config *rest.Config // Cluster config, e.g., through $KUBECONFIG file.
 
 	clientSet  *clients.DynamicClientSet
 	logClient  *clients.LogClient
@@ -326,9 +328,9 @@ func (k *kubeProvider) Configure(_ context.Context, req *pulumirpc.ConfigureRequ
 			// operations that require a valid cluster. This will allow us to perform invoke operations
 			// using the default provider.
 			k.clusterUnreachable = true
-			glog.V(3).Infof(fmt.Sprintf("failed to parse kubeconfig data in "+
+			k.clusterUnreachableReason = fmt.Sprintf("failed to parse kubeconfig data in "+
 				"`kubernetes:config:kubeconfig`; this must be a YAML literal string and not "+
-				"a filename or path - %v", err))
+				"a filename or path - %v", err)
 		} else {
 			kubeconfig = clientcmd.NewDefaultClientConfig(*config, overrides)
 			configurationNamespace, _, err := kubeconfig.Namespace()
@@ -350,13 +352,20 @@ func (k *kubeProvider) Configure(_ context.Context, req *pulumirpc.ConfigureRequ
 		k.defaultNamespace = defaultNamespace
 	}
 
+	// Attempt to load the configuration from the provided kubeconfig. If this fails, mark the cluster as unreachable.
 	if !k.clusterUnreachable {
 		config, err := kubeconfig.ClientConfig()
 		if err != nil {
-			return nil, fmt.Errorf("unable to load Kubernetes client configuration from kubeconfig file: %v", err)
+			k.clusterUnreachable = true
+			k.clusterUnreachableReason = fmt.Sprintf(
+				"unable to load Kubernetes client configuration from kubeconfig file: %v", err)
+		} else {
+			k.config = config
 		}
-		k.config = config
+	}
 
+	// These operations require a reachable cluster.
+	if !k.clusterUnreachable {
 		cs, err := clients.NewDynamicClientSet(k.config)
 		if err != nil {
 			return nil, err
@@ -373,7 +382,8 @@ func (k *kubeProvider) Configure(_ context.Context, req *pulumirpc.ConfigureRequ
 
 		if _, err = k.getResources(); err != nil {
 			k.clusterUnreachable = true
-			glog.V(3).Infof("unable to load schema information from the API server: %v", err)
+			k.clusterUnreachableReason = fmt.Sprintf(
+				"unable to load schema information from the API server: %v", err)
 		}
 	}
 
@@ -476,7 +486,7 @@ func (k *kubeProvider) StreamInvoke(
 		//
 
 		if k.clusterUnreachable {
-			return fmt.Errorf("configured Kubernetes cluster is unreachable")
+			return fmt.Errorf("configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason)
 		}
 
 		namespace := ""
@@ -570,7 +580,7 @@ func (k *kubeProvider) StreamInvoke(
 		//
 
 		if k.clusterUnreachable {
-			return fmt.Errorf("configured Kubernetes cluster is unreachable")
+			return fmt.Errorf("configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason)
 		}
 
 		namespace := ""
@@ -654,7 +664,7 @@ func (k *kubeProvider) StreamInvoke(
 		//
 
 		if k.clusterUnreachable {
-			return fmt.Errorf("configured Kubernetes cluster is unreachable")
+			return fmt.Errorf("configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason)
 		}
 
 		namespace := "default"
@@ -1182,7 +1192,7 @@ func (k *kubeProvider) Create(
 
 	// Create requires a connection to a k8s cluster, so bail out immediately if it is unreachable.
 	if k.clusterUnreachable {
-		return nil, fmt.Errorf("configured Kubernetes cluster is unreachable")
+		return nil, fmt.Errorf("configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason)
 	}
 
 	// Parse inputs
@@ -1310,7 +1320,8 @@ func (k *kubeProvider) Read(ctx context.Context, req *pulumirpc.ReadRequest) (*p
 
 	// If the cluster is unreachable, consider the resource deleted and inform the user.
 	if k.clusterUnreachable {
-		_ = k.host.Log(ctx, diag.Warning, urn, fmt.Sprintf("configured Kubernetes cluster is unreachable"))
+		_ = k.host.Log(ctx, diag.Warning, urn, fmt.Sprintf(
+			"configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason))
 		return deleteResponse, nil
 	}
 
@@ -1520,7 +1531,7 @@ func (k *kubeProvider) Update(
 
 	// Update requires a connection to a k8s cluster, so bail out immediately if it is unreachable.
 	if k.clusterUnreachable {
-		return nil, fmt.Errorf("configured Kubernetes cluster is unreachable")
+		return nil, fmt.Errorf("configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason)
 	}
 
 	// Obtain old properties, create a Kubernetes `unstructured.Unstructured`.
@@ -1640,7 +1651,7 @@ func (k *kubeProvider) Delete(
 
 	// If the cluster is unreachable, consider the resource deleted and inform the user.
 	if k.clusterUnreachable {
-		_ = k.host.Log(ctx, diag.Warning, urn, fmt.Sprintf("configured Kubernetes cluster is unreachable"))
+		_ = k.host.Log(ctx, diag.Warning, urn, fmt.Sprintf("configured Kubernetes cluster is unreachable: %s", k.clusterUnreachableReason))
 		return &pbempty.Empty{}, nil
 	}