Changes how the Engine interacts with Registry servers on image pull.
Previously, Engine sent a User-Agent string to the Registry server
that included only the Engine's version information. This commit
appends to that string the fields from the User-Agent sent by the
client (e.g., Compose) of the Engine. This allows Registry server
operators to understand what tools are actually generating pulls on
their registries.
Signed-off-by: Mike Goelzer <mgoelzer@docker.com>
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>
- Use layer DiffIDs for progress output in v1 push. This makes the
output consistent with v2 pushes, which means that a fallback to v1
won't start progress bars for a different set of IDs.
- Change wording used in v1 status updates to be consistent with v2.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.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>
Mike Goelzer