Due to a missing functionality in PythonTest, `unshare` is never used
to mount volumes. As a consequence:
+ volumes are created with sudo which is undesired
+ they are not cleared automatically
Even having the missing support in place, the approach with mounting
volumes with `unshare` would not work as http server, a pool of clusters,
and scylla cluster manager are started outside of the new namespace.
Thus cluster would have no access to volumes created with `unshare`.
The new approach that works with and without dbuild and does not require
sudo, uses the following three commands to mount a volume:
truncate -s 100M /tmp/mydevice.img
mkfs.ext4 /tmp/mydevice.img
fuse2fs /tmp/mydevice.img test/
Additionally, a proper cleanup is performed, i.e. servers are stopped
gracefully and and volumes are unmounted after the tests using them are
completed.
Fixes: https://github.com/scylladb/scylladb/issues/25906Closesscylladb/scylladb#26065
The storage submodule contains tests that require mounted volumes
to be executed. The volumes are created automatically with the
`volumes_factory` fixture.
The tests in this suite are executed with the custom launcher
`unshare -mr pytest`
Test scenarios (when one node reaches critical disk utilization):
1. Reject user table writes
2. Disable/Enabled compaction
3. Reject split compactions
4. New split compactions not triggered
5. Abort tablet repair
6. Disable/Enabled incoming tablet migrations
7. Restart a node while a tablet split is triggered
