log and skip backups for non-existent & hostPath volumes

Signed-off-by: Steve Kriss <steve@heptio.com>

pkg/restic/backupper.go

@@ -115,9 +115,27 @@ func (b *backupper) BackupPodVolumes(backup *arkv1api.Backup, pod *corev1api.Pod
 	var (
 		errs            []error
 		volumeSnapshots = make(map[string]string)
+		podVolumes      = make(map[string]corev1api.Volume)
 	)
 
+	// put the pod's volumes in a map for efficient lookup below
+	for _, podVolume := range pod.Spec.Volumes {
+		podVolumes[podVolume.Name] = podVolume
+	}
+
 	for _, volumeName := range volumesToBackup {
+		if !volumeExists(podVolumes, volumeName) {
+			log.Warnf("No volume named %s found in pod %s/%s, skipping", volumeName, pod.Namespace, pod.Name)
+			continue
+		}
+
+		// hostPath volumes are not supported because they're not mounted into /var/lib/kubelet/pods, so our
+		// daemonset pod has no way to access their data.
+		if isHostPathVolume(podVolumes, volumeName) {
+			log.Warnf("Volume %s in pod %s/%s is a hostPath volume which is not supported for restic backup, skipping", volumeName, pod.Namespace, pod.Name)
+			continue
+		}
+
 		volumeBackup := newPodVolumeBackup(backup, pod, volumeName, repo.Spec.ResticIdentifier)
 
 		if err := errorOnly(b.repoManager.arkClient.ArkV1().PodVolumeBackups(volumeBackup.Namespace).Create(volumeBackup)); err != nil {
@@ -152,6 +170,20 @@ ForEachVolume:
 	return volumeSnapshots, errs
 }
 
+func volumeExists(podVolumes map[string]corev1api.Volume, volumeName string) bool {
+	_, found := podVolumes[volumeName]
+	return found
+}
+
+func isHostPathVolume(podVolumes map[string]corev1api.Volume, volumeName string) bool {
+	volume, found := podVolumes[volumeName]
+	if !found {
+		return false
+	}
+
+	return volume.HostPath != nil
+}
+
 func newPodVolumeBackup(backup *arkv1api.Backup, pod *corev1api.Pod, volumeName, repoIdentifier string) *arkv1api.PodVolumeBackup {
 	return &arkv1api.PodVolumeBackup{
 		ObjectMeta: metav1.ObjectMeta{

pkg/restic/backupper_test.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2018 the Heptio Ark contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package restic
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	corev1api "k8s.io/api/core/v1"
+)
+
+func TestVolumeExists(t *testing.T) {
+	podVolumes := map[string]corev1api.Volume{
+		"foo": {},
+		"bar": {},
+	}
+
+	assert.True(t, volumeExists(podVolumes, "foo"))
+	assert.True(t, volumeExists(podVolumes, "bar"))
+	assert.False(t, volumeExists(podVolumes, "non-existent volume"))
+}
+
+func TestIsHostPathVolume(t *testing.T) {
+	podVolumes := map[string]corev1api.Volume{
+		"foo": {
+			VolumeSource: corev1api.VolumeSource{
+				HostPath: &corev1api.HostPathVolumeSource{},
+			},
+		},
+		"bar": {},
+	}
+
+	assert.True(t, isHostPathVolume(podVolumes, "foo"))
+	assert.False(t, isHostPathVolume(podVolumes, "bar"))
+	assert.False(t, isHostPathVolume(podVolumes, "non-existent volume"))
+}