Several improvements to error handling:
- Introduce ImageConfigPullError type, wrapping errors related to
downloading the image configuration blob in schema2. This allows for a
more descriptive error message to be seen by the end user.
- Change some logrus.Debugf calls that display errors to logrus.Errorf.
Add log lines in the push/pull fallback cases to make sure the errors
leading to the fallback are shown.
- Move error-related types and functions which are only used by the
distribution package out of the registry package.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
`Upload` already closes the reader returned by `compress` and the
progressreader passed into it, before returning. But even so, the
io.Copy inside compress' goroutine needs to attempt a read from the
progressreader to notice that it's closed, and this read has a side
effect of outputting a progress message. If this happens after `Upload`
returns, it can result in a write to a closed channel. Change `compress`
to return a channel that allows the caller to wait for its goroutine to
finish before freeing any resources connected to the reader that was
passed to it.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Currently this always uses the schema1 manifest builder. Later, it will
be changed to attempt schema2 first, and fall back when necessary.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
- Stop serializing JSONMessage in favor of events.Message.
- Keep backwards compatibility with JSONMessage for container events.
Signed-off-by: David Calavera <david.calavera@gmail.com>
If we detect a Docker-Distribution-Api-Version header indicating that
the registry speaks the V2 protocol, no fallback to V1 should take
place.
The same applies if a V2 registry operation succeeds while attempting a
push or pull.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
This commit adds a transfer manager which deduplicates and schedules
transfers, and also an upload manager and download manager that build on
top of the transfer manager to provide high-level interfaces for uploads
and downloads. The push and pull code is modified to use these building
blocks.
Some benefits of the changes:
- Simplification of push/pull code
- Pushes can upload layers concurrently
- Failed downloads and uploads are retried after backoff delays
- Cancellation is supported, but individual transfers will only be
cancelled if all pushes or pulls using them are cancelled.
- The distribution code is decoupled from Docker Engine packages and API
conventions (i.e. streamformatter), which will make it easier to split
out.
This commit also includes unit tests for the new distribution/xfer
package. The tests cover 87.8% of the statements in the package.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
