Prevents having multiple database connections open to a connection,
preventing bugs with locking by relying on the boltdb database
object to handle synchronization rather than file locking.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
Adds back links from parent to children in order to prevent
deletion of a referenced snapshot in a namespace.
Avoid removing snapshot during metadata delete to
prevent shared namespaces from being mistakenly deleted.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
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>
Now that we have most of the services required for use with containerd,
it was found that common patterns were used throughout services. By
defining a central `errdefs` package, we ensure that services will map
errors to and from grpc consistently and cleanly. One can decorate an
error with as much context as necessary, using `pkg/errors` and still
have the error mapped correctly via grpc.
We make a few sacrifices. At this point, the common errors we use across
the repository all map directly to grpc error codes. While this seems
positively crazy, it actually works out quite well. The error conditions
that were specific weren't super necessary and the ones that were
necessary now simply have better context information. We lose the
ability to add new codes, but this constraint may not be a bad thing.
Effectively, as long as one uses the errors defined in `errdefs`, the
error class will be mapped correctly across the grpc boundary and
everything will be good. If you don't use those definitions, the error
maps to "unknown" and the error message is preserved.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Remove rootfs service in place of snapshot service. Adds
diff service for extracting and creating diffs. Diff
creation is not yet implemented. This service allows
pulling or creating images without needing root access to
mount. Additionally in the future this will allow containerd
to ensure extractions happen safely in a chroot if needed.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
The split between provider and ingester was a long standing division
reflecting the client-side use cases. For the most part, we were
differentiating these for the algorithms that operate them, but it made
instantation and use of the types challenging. On the server-side, this
distinction is generally less important. This change unifies these types
and in the process we get a few benefits.
The first is that we now completely access the content store over GRPC.
This was the initial intent and we have now satisfied this goal
completely. There are a few issues around listing content and getting
status, but we resolve these with simple streaming and regexp filters.
More can probably be done to polish this but the result is clean.
Several other content-oriented methods were polished in the process of
unification. We have now properly seperated out the `Abort` method to
cancel ongoing or stalled ingest processes. We have also replaced the
`Active` method with a single status method.
The transition went extremely smoothly. Once the clients were updated to
use the new methods, every thing worked as expected on the first
compile.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This adds pause and unpause to containerd's execution service and the
same commands to the `ctr` client.
Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.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>
Adds a zero byte separator on composite key.
Stores child key in back reference to allow following.
Add parent bucket to get/create bucket functions.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
