An admin wants to specify in which AWS availability zone(s) users may create persistent volumes using dynamic provisioning.
That's why the admin can now configure in StorageClass object a comma separated list of zones. Dynamically created PVs for PVCs that use the StorageClass are created in one of the configured zones.
We are more liberal in what we accept as a volume id in k8s, and indeed
we ourselves generate names that look like `aws://<zone>/<id>` for
dynamic volumes.
This volume id (hereafter a KubernetesVolumeID) cannot directly be
compared to an AWS volume ID (hereafter an awsVolumeID).
We introduce types for each, to prevent accidental comparison or
confusion.
Issue #35746
Gluster provisioner is interested in pvc.Namespace and I don't want to add
at as a new field in VolumeOptions - it would contain almost whole PVC.
Let's pass direct reference to PVC instead and let the provisioner to pick
information it is interested in.
Long term we plan on integrating this into the scheduler, but in the
short term we use the volume name to place it onto a zone.
We hash the volume name so we don't bias to the first few zones.
If the volume name "looks like" a PetSet volume name (ending with
-<number>) then we use the number as an offset. In that case we hash
the base name.
Fixes#27256
AWS has soft support limit for 40 attached EBS devices. Assuming there is just
one root device, use the rest for persistent volumes.
The devices will have name /dev/xvdba - /dev/xvdcm, leaving /dev/sda - /dev/sdz
to the system.
Also, add better error handling and propagate error
"Too many EBS volumes attached to node XYZ" to a pod.
Similar to #11543, the local hostname is not guaranteed to be the node
name, as the AWS cloud provider looks up node name using
`private-dns-name`. This value can be different such as when using a
private hosted zone.
The previous code uses GetHostName(), which fails in this case. Instead,
pass in an empty string so the aws cloud provider will use the cached
self instance to find the instance id.
Authors: @balooo, @dogan-sky, @jsravn
Volume names have now format <cluster-name>-dynamic-<pv-name>.
pv-name is guaranteed to be unique in Kubernetes cluster, adding
<cluster-name> ensures we don't conflict with any running cluster
in the cloud project (kube-controller-manager --cluster-name=XXX).
'kubernetes' is the default cluster name.
We are (sadly) using a copy-and-paste of the GCE PD code for AWS EBS.
This code hasn't been updated in a while, and it seems that the GCE code
has some code to make volume mounting more robust that we should copy.
The GCE PD plugin uses safe_format_and_mount found on standard GCE images:
https://github.com/GoogleCloudPlatform/compute-image-packages/blob/master/google-startup-scripts/usr/share/google/safe_format_and_mount
On custom images where this is not available pods fail to format and
mount GCE PDs. This patch uses linux utilities in a similar way to the
safe_format_and_mount script to format and mount the GCE PD and AWS EBC
devices. That is first attempt a mount. If mount fails try to use file to
investigate the device. If 'file' fails to get any information about
the device and simply returns "data" then assume the device is not
formatted and format it and attempt to mount it again.
Signed-off-by: Sami Wagiaalla <swagiaal@redhat.com>
IsLikelyNotMountPoint determines if a directory is not a mountpoint.
It is fast but not necessarily ALWAYS correct. If the path is in fact
a bind mount from one part of a mount to another it will not be detected.
mkdir /tmp/a /tmp/b; mount --bin /tmp/a /tmp/b; IsLikelyNotMountPoint("/tmp/b")
will return true. When in fact /tmp/b is a mount point. So this patch
renames the function and switches it from a positive to a negative (I
could think of a good positive name). This should make future users of
this function aware that it isn't quite perfect, but probably good
enough.
Chao Xu