Update snapshot storage to use boltdb keys instead of protobuf.
Add update function to snapshotter to allow updating labels.
Add option type for creating snapshots to allow setting labels.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
What started out as a simple PR to remove the "Readonly" column became an
adventure to add a proper type for a "View" snapshot. The short story here is
that we now get the following output:
```
$ sudo ctr snapshot ls
ID PARENT KIND
sha256:08c2295a7fa5c220b0f60c994362d290429ad92f6e0235509db91582809442f3 Committed
testing4 sha256:08c2295a7fa5c220b0f60c994362d290429ad92f6e0235509db91582809442f3 Active
```
In pursuing this output, it was found that the idea of having "readonly" as an
attribute on all snapshots was redundant. For committed, they are always
readonly, as they are not accessible without an active snapshot. For active
snapshots that were views, we'd have to check the type before interpreting
"readonly". With this PR, this is baked fully into the kind of snapshot. When
`Snapshotter.View` is called, the kind of snapshot is `KindView`, and the
storage system reflects this end to end.
Unfortunately, this will break existing users. There is no migration, so they
will have to wipe `/var/lib/containerd` and recreate everything. However, this
is deemed worthwhile at this point, as we won't have to judge validity of the
"Readonly" field when new snapshot types are added.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
We may want to create this as a subvolume if the parent is btrfs
or support mounting on load in the future.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This moves both the Mount type and mountinfo into a single mount
package.
This also opens up the root of the repo to hold the containerd client
implementation.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
To allow the querying of usage for snapshots, we define a new method on
the snapshotter to query the resources in use by a single snapshot.
Conversely, it can be said that if the snapshot was deleted, the
reported amount of usage would be recovered.
There are few problems with this model in the implementation of btrfs
that need to be worked out. In btrfs, it is hard to resolve the amount
of data usage with the use of quotas but these may report valuables that
are incompatible with the model.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
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>
Ensure undo failures are logged in a consistent way.
Remove created subvolume on commit failure on create.
Ensure that removed value get logged on delete failure.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Updates the btrfs snapshotter to meet the interface and current tests.
Mostly, we merge the keyspace into a common index. Like with the overlay
driver, we will still need to do more verification work to ensure
idempotence of key collisions.
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>
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>
