Error when importing snapshots #94
Description
Hi,
I have a problem with importing snapshots to Kubernetes. I managed to create a custom Kubernetes Cluster (version 1.13 and the nodes are VMs from Google Cloud) with GPD CSI driver (version DEV where it uses external provisioner, snapshotter v1.0.1) installed. I was able to provision volumes, create snapshots and restore volumes from snapshots.
Next, I decided to import existing snapshots that I am keeping in Google Cloud. After reading https://kubernetes.io/blog/2018/10/09/introducing-volume-snapshot-alpha-for-kubernetes/, the section Importing an existing snapshot with Kubernetes, I started to import my existing snapshots in Google Cloud, with the method explained in the blog post.
Here are the steps that I applied:
I created a VolumeSnapshotContent with:
$ cat <<EOF | kubectl create -f -
apiVersion: snapshot.storage.k8s.io/v1alpha1
kind: VolumeSnapshotContent
metadata:
name: imported-snap-content
spec:
csiVolumeSnapshotSource:
driver: pd.csi.storage.gke.io
snapshotHandle: {GCP_SNAP_ID}
volumeSnapshotRef:
kind: VolumeSnapshot
name: imported-snap
namespace: temp-namespace
EOF
After that, I created a VolumeSnapshot with the same reference I used in VolumeSnapshotContent:
$ cat << EOF | kubectl create -f -
apiVersion: snapshot.storage.k8s.io/v1alpha1
kind: VolumeSnapshot
metadata:
name: imported-snap
namespace: temp-namespace
spec:
snapshotClassName: default-snapshot-class
snapshotContentName: imported-snap-content
EOF
default-snapshot-class is the VolumeSnapshotClass from https://github.com/kubernetes-sigs/gcp-compute-persistent-disk-csi-driver/blob/master/examples/kubernetes/demo-defaultsnapshotclass.yaml
So, I checked the VolumeSnapshotContent first:
$ kubectl get volumesnapshotcontent imported-snap-content -oyaml
apiVersion: snapshot.storage.k8s.io/v1alpha1
kind: VolumeSnapshotContent
metadata:
creationTimestamp: 2019-02-15T18:31:47Z
finalizers:
- snapshot.storage.kubernetes.io/volumesnapshotcontent-protection
generation: 3
name: imported-snap-content
resourceVersion: "475063"
selfLink: /apis/snapshot.storage.k8s.io/v1alpha1/volumesnapshotcontents/imported-snap-content
uid: f399dfcc-314f-11e9-b4da-42010a8a004e
spec:
csiVolumeSnapshotSource:
driver: pd.csi.storage.gke.io
snapshotHandle: {GCP-SNAP-ID}
deletionPolicy: null
persistentVolumeRef: null
snapshotClassName: default-snapshot-class
volumeSnapshotRef:
kind: VolumeSnapshot
name: imported-snap
namespace: temp-namespace
uid: f861fa81-314f-11e9-b4da-42010a8a004e
It looks like the snapshot controller managed to bind it to a VolumeSnapshot since uid field in volumeSnapshotRef is filled.
Then, I looked the details of VolumeSnapshot that I created before:
$ kubectl get volumesnapshot imported-snap -n temp-namespace -oyaml
apiVersion: snapshot.storage.k8s.io/v1alpha1
kind: VolumeSnapshot
metadata:
creationTimestamp: 2019-02-15T18:31:55Z
finalizers:
- snapshot.storage.kubernetes.io/volumesnapshot-protection
generation: 3
name: imported-snap
namespace: temp-namespace
resourceVersion: "475064"
selfLink: /apis/snapshot.storage.k8s.io/v1alpha1/namespaces/temp-namespace/volumesnapshots/imported-snap
uid: f861fa81-314f-11e9-b4da-42010a8a004e
spec:
snapshotClassName: default-snapshot-class
snapshotContentName: imported-snap-content
source: null
status:
creationTime: null
error:
message: 'Failed to check and update snapshot: failed to get input parameters
to create snapshot imported-snap: "the snapshot source is not specified."'
time: 2019-02-15T18:31:55Z
readyToUse: false
restoreSize: null
The UID matches with the one in the reference. However, the controller registers a problem saying that source is not specified. When I look at the API detail, I see that source is a field for recording the originated volume in Kubernetes Cluster. It is interesting since I didn’t create a snapshot from a PVC, but I was trying to import a snapshot. In this case, I expect a null source is the normal thing.
What can I do to solve this problem? Are there some steps that I couldn’t do properly or am I missing some steps?