When starting up a snapshot driver on subsequent runs, the
mkdir call will return an exist error, this can be safely
ignored.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
We need to set +x on the overlay dirs or after dropping from root to a
non-root user an eperm will happen on exec or other file access
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Allow creating actives without an upper directory for
capturing changes. Actives without the upper directory
will always be mounted read only. Read only actives
must have a parent.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
With the change to the snapshotter interface, we've now updated the
overlay driver to follow the conventions of the current test suite. To
support key unification, an hashed index was added to active and
committed directories. We still need to do some testing around
collisions, but we'll leave that for a future PR.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
We now include btrfs in the snapshot driver test suite. This includes
the addition of parent links and name hashing into the btrfs driver.
We'll probably endup replacing this with a common metadata store, as
these relationships are generally identical between implementations.
A small bug was discovered in the delete implementation in the course
testing, so the btrfs package has been updated with a fix.
The overlay driver was modified accordingly with the btrfs driver to use
`Driver` as the exported type of each driver packge.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
We now define the `snapshot.Driver` interface based on earlier work.
Many details of the model are worked out, such as snapshot lifecycle and
parentage of commits against "Active" snapshots.
The impetus of this change is to provide a snapshot POC that does a
complete push/pull workflow. The beginnings of a test suite for snapshot
drivers is included that we can use to verify the assumptions of
drivers. The intent is to port the existing tests over to this test
suite and start scaling contributions and test to the snapshot driver
subsystem.
There are still some details that need to be worked out, such as listing
and metadata access. We can do this activity as we further integrate
with tooling.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Also remove the target from the Mount struct because it should not be
used at all. The target can be variable and set by a caller, not by the
snapshot drivers.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
