Several API tests were added to ensure correct acceptance of zero-size and
empty tar files. This led to several changes in the storage backend around the
guarantees of remote file reading, which backs the layer and layer upload type.
In support of these changes, zero-length and empty checks have been added to
the digest package. These provide a sanity check against upstream tarsum
changes. The fileReader has been modified to be more robust when reading and
seeking on zero-length or non-existent files. The file no longer needs to exist
for the reader to be created. Seeks can now move beyond the end of the file,
causing reads to issue an io.EOF. This eliminates errors during certain race
conditions for reading files which should be detected by stat calls. As a part
of this, a few error types were factored out and the read buffer size was
increased to something more reasonable.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This changeset addresses intermittent internal server errors encountered during
pushes. The root cause has been isolated to layers that result in identical,
empty filesystems but may have some path declarations (imaginge "./"),
resulting in different tarsums. The main error message reported during these
upload problems was a 500 error, which was not correct. Further investigation
showed the errors to be rooted in digest verification when finishing uploads.
Inspection of the surrounding code also identified a few issues. PutLayerChunk
was slightly refactered into PutLayerUploadComplete. Helper methods were
avoided to make handler less confusing. This simplification leveraged an
earlier change in the spec that moved non-complete chunk uploads to the PATCH
method. Simple logging was also added in the unknown error case that should
help to avoid mysterious 500 errors in the future.
At the same time, the glaring omission of a proper layer upload cancel method
was rectified. This has been added in this change so it is not missed in the
future.
In the future, we may want to refactor the handler code to be more
straightforward, hopefully letting us avoid these problems in the future.
Added test cases that reproduce these errors and drove these changes include
the following:
1. Push a layer with an empty body results in invalid blob upload.
2. Push a layer with a different tarsum (in this case, empty tar)
3. Deleting a layer upload works.
4. Getting status on a deleted layer upload returns 404.
Common functionality was grouped into shared functions to remove repitition.
The API tests will still require future love.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Also removed ModTime checks on directories as it is not
required and some drivers might fail to provide it.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
This change provides a toolkit for intercepting registry calls, such as
`ManifestService.Get` and `LayerUpload.Finish`, with the goal of easily
supporting interesting callbacks and listeners. The package proxies
returned objects through the decorate function before creation, allowing one to
carefully choose injection points.
Use cases range from notification systems all the way to cache integration.
While such a tool isn't strictly necessary, it reduces the amount of code
required to accomplish such tasks, deferring the tricky aspects to the
decorator package.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This speeds up the build (and makes it more consistent) since it doesn't have to clone a bunch of repos. 👍
Signed-off-by: Andrew "Tianon" Page <admwiggin@gmail.com>
Setting a header for all responses can help clients better determine
if the server speaks the legacy v1 API or the v2 API. It is important
that the header be set *BEFORE* routing the request.
Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
In support of making the storage API ready for supporting notifications and
mirroring, we've begun the process of paring down the storage model. The
process started by creating a central Registry interface. From there, the
common name argument on the LayerService and ManifestService was factored into
a Repository interface. The rest of the changes directly follow from this.
An interface wishlist was added, suggesting a direction to take the registry
package that should support the distribution project's future goals. As these
objects move out of the storage package and we implement a Registry backed by
the http client, these design choices will start getting validation.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This change refactors the storage backend to use the new path layout. To
facilitate this, manifest storage has been separated into a revision store and
tag store, supported by a more general blob store. The blob store is a hybrid
object, effectively providing both small object access, keyed by content
address, as well as methods that can be used to manage and traverse links to
underlying blobs. This covers common operations used in the revision store and
tag store, such as linking and traversal. The blob store can also be updated to
better support layer reading but this refactoring has been left for another
day.
The revision store and tag store support the manifest store's compound view of
data. These underlying stores provide facilities for richer access models, such
as content-addressable access and a richer tagging model. The highlight of this
change is the ability to sign a manifest from different hosts and have the
registry merge and serve those signatures as part of the manifest package.
Various other items, such as the delegate layer handler, were updated to more
directly use the blob store or other mechanism to fit with the changes.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Several requirements for storing registry data have been compiled and the
backend layout has been refactored to comply. Specifically, we now store most
data as blobs that are linked from repositories. All data access is traversed
through repositories. Manifest updates are no longer destructive and support
references by digest or tag. Signatures for manifests are now stored externally
to the manifest payload to allow merging of signatures posted at different
time.
The design is detailed in the documentation for pathMapper.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Detecting tar files then falling back for calculating digests turned out to be
fairly unreliable. Likely, the implementation was broken for content that was
not a tarfile. Also, for the use case of the registry, it is really not needed.
This functionality has been removed in FromReader and FromBytes. FromTarArchive
has been added for convenience.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
