Add support to detect for shutdown nodes

The CCM's node controller will call upon InstanceShutdownByProviderID()
to determine whether or not the node has been powered off when it goes
`NotReady`, and adds shutdown taints to the node to force pods to be
evicted from the node.

Author: sibucan

cloud/linode/instances.go

@@ -176,5 +176,29 @@ func (i *instances) InstanceExistsByProviderID(ctx context.Context, providerID s
 }
 
 func (i *instances) InstanceShutdownByProviderID(ctx context.Context, providerID string) (bool, error) {
-	return false, cloudprovider.NotImplemented
+	ctx = sentry.SetHubOnContext(ctx)
+	sentry.SetTag(ctx, "provider_id", providerID)
+
+	id, err := parseProviderID(providerID)
+	if err != nil {
+		sentry.CaptureError(ctx, err)
+		return false, err
+	}
+
+	sentry.SetTag(ctx, "linode_id", strconv.Itoa(id))
+
+	instance, err := linodeByID(ctx, i.client, id)
+	if err != nil {
+		sentry.CaptureError(ctx, err)
+		return false, err
+	}
+
+	// An instance is considered to be "shutdown" when it is
+	// in the process of shutting down, or already offline.
+	if instance.Status == linodego.InstanceOffline ||
+		instance.Status == linodego.InstanceShuttingDown {
+		return true, nil
+	}
+
+	return false, nil
 }

cloud/linode/instances_test.go

@@ -314,7 +314,56 @@ func TestAddSSHKeyToAllInstances(t *testing.T) {
 }
 
 func TestInstanceShutdownByProviderID(t *testing.T) {
-	instances := newInstances(nil)
-	_, err := instances.InstanceShutdownByProviderID(context.TODO(), providerIDPrefix+"12345")
-	assert.ErrorIs(t, err, cloudprovider.NotImplemented)
+	ctx := context.TODO()
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	client := NewMockClient(ctrl)
+	instances := newInstances(client)
+
+	t.Run("fails when instance not found", func(t *testing.T) {
+		id := 12345
+		providerID := providerIDPrefix + strconv.Itoa(id)
+		client.EXPECT().GetInstance(gomock.Any(), id).Times(1).Return(nil, linodego.Error{Code: http.StatusNotFound})
+		shutdown, err := instances.InstanceShutdownByProviderID(ctx, providerID)
+
+		assert.Error(t, err)
+		assert.False(t, shutdown)
+	})
+
+	t.Run("returns true when instance is shut down", func(t *testing.T) {
+		id := 12345
+		providerID := providerIDPrefix + strconv.Itoa(id)
+		client.EXPECT().GetInstance(gomock.Any(), id).Times(1).Return(&linodego.Instance{
+			ID: id, Label: "offline-linode", Status: linodego.InstanceOffline,
+		}, nil)
+		shutdown, err := instances.InstanceShutdownByProviderID(ctx, providerID)
+
+		assert.NoError(t, err)
+		assert.True(t, shutdown)
+	})
+
+	t.Run("returns true when instance is shutting down", func(t *testing.T) {
+		id := 12345
+		providerID := providerIDPrefix + strconv.Itoa(id)
+		client.EXPECT().GetInstance(gomock.Any(), id).Times(1).Return(&linodego.Instance{
+			ID: id, Label: "shutting-down-linode", Status: linodego.InstanceShuttingDown,
+		}, nil)
+		shutdown, err := instances.InstanceShutdownByProviderID(ctx, providerID)
+
+		assert.NoError(t, err)
+		assert.True(t, shutdown)
+	})
+
+	t.Run("returns false when instance is running", func(t *testing.T) {
+		id := 12345
+		providerID := providerIDPrefix + strconv.Itoa(id)
+		client.EXPECT().GetInstance(gomock.Any(), id).Times(1).Return(&linodego.Instance{
+			ID: id, Label: "running-linode", Status: linodego.InstanceRunning,
+		}, nil)
+		shutdown, err := instances.InstanceShutdownByProviderID(ctx, providerID)
+
+		assert.NoError(t, err)
+		assert.False(t, shutdown)
+	})
 }