`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>
Tracks source repository information for each blob in the blobsum
service, which is then used to attempt to mount blobs from another
repository when pushing instead of having to re-push blobs to the same
registry.
Signed-off-by: Brian Bland <brian.bland@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>
The trust code used to parse the console output of `docker push` to
extract the digest, tag, and size information and determine what to
sign. This is fragile and might give an attacker control over what gets
signed if the attacker can find a way to influence what gets printed as
part of the push output.
This commit sends the push metadata out-of-band. It introduces an `Aux`
field in JSONMessage that can carry application-specific data alongside
progress updates. Instead of parsing formatted output, the client looks
in this field to get the digest, size, and tag from the push.
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>
Currently, the resources associated with the io.Reader returned by
TarStream are only freed when it is read until EOF. This means that
partial uploads or exports (for example, in the case of a full disk or
severed connection) can leak a goroutine and open file. This commit
changes TarStream to return an io.ReadCloser. Resources are freed when
Close is called.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
