Stephen J Day 863784f991 snapshot: replace "readonly" with View snapshot type ... 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>		2017-07-24 16:58:01 -07:00
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services	snapshot: replace "readonly" with View snapshot type	2017-07-24 16:58:01 -07:00
types	Add Exec IDs	2017-07-06 15:23:08 -07:00