Make pre provisioned snapshots using CSI driver by
1. Take a dynamic snapshot with retain policy
2. Delete the dynamic snapshot and content
3. Create a preprovisioned snapshot with snapshotHandle
This commit adds a preprovisiond test pattern, all snapshots made using
create snapshot resource become prepv snapshots. All exisitng test cases
now run again with prepv snapshots.
Some of the content was out-dated (`ShortName` was removed,
`dataSource` renamed). Better refer to the actual definitions with
functional links.
To make it simpler to find those, `driverDefinition` gets moved up in
`external.go`.
test/e2e/storage/testsuites creates volumes dynamically. Initially, the size of those volumes was
hard-coded in the test, which prevented using the tests with storage backends that couldn't support
that hard-coded size
The assumption so far was that all drivers support read/write
volumes. That might not necessarily be true, so we have to let the
test driver specify it and then test accordingly.
Another aspect that is worth testing is whether the driver correctly
creates a new volume for each pod even if the volume attributes are
the same. However, drivers are not required to do that, so again we
have to let the test driver specify that.
The conceptual change is that the mode in which a volume gets handled
is derived from it's spec, not from the ability of the driver. In
practice, that is already how the code worked because it didn't
actually look at CSIDriver.Spec.Mode at all.
Therefore the code change itself is mostly just renaming "driver mode"
to "volume mode". In some places (CanDeviceMount, CanAttach) the
feature check that was used elsewhere seemed to be missing. Now their
code path for ephemeral volumes are also only entered if that feature
is enabled.
The sanity check whether a CSI driver is being used correctly still
needs to be implemented.
Related-to: https://github.com/kubernetes/kubernetes/issues/79624
Tests should never directly add to the global command line, because
some users of the tests might not want them there. For example,
options might only get set directly from a config file.
To achieve that, e2e/framework/config, e2e/framework/viperconfig, and
e2e/framework/test_context.go avoid using the global flag set and
instead expect to be told by the caller which flag set to use. Tests
that called flag directly either get updated or obsolete flags get
removed.
The exception is framework.HandleFlags, which as before directly
implements global command line handling.
This is a breaking change for test suites which do not use that
function (and only those): they now need to ensure that they copy
individual flags from tests. Because the RegisterCommonFlags prototype
has changed, test suite authors will notice due to the resulting
compilation errors.
One previously undocumented expectation is that
GetDynamicProvisionStorageClass can be called more than once per test
and then each time returns a new, unique storage class. The in-memory
implementation in driveroperations.go:GetStorageClass ensured that,
but loading from a .yaml file didn't. This caused the multivolume tests
to fail when applied to an already installed GCE driver with the
-storage.testdriver parameter.
When using an already installed driver, the snapshot name is the
original driver name. Renaming was incorrectly copied from the in-tree
CSI hostpath driver.
It is useful to apply the storage testsuite also to "external" (=
out-of-tree) storage drivers. One way of doing that is setting up a
custom E2E test suite, but that's still quite a bit of work.
An easier alternative is to parameterize the Kubernetes e2e.test
binary at runtime so that it instantiates the testsuite for one or
more drivers. Some parameters have to be provided before starting the
test because they define configuration and capabilities of the driver
and its storage backend that cannot be discovered at runtime. This is
done by populating the DriverDefinition with the content of the file
that the new -storage.testdriver parameters points to.
The universal .yaml and .json decoder from Kubernetes is used. It's
flexible, but has some downsides:
- currently ignores unknown fields (see https://github.com/kubernetes/kubernetes/pull/71589)
- poor error messages when fields have the wrong type
Storage drivers have to be installed in the test cluster before
starting e2e.test. Only tests involving dynamically provisioned
volumes are currently supported.
