Back in the before time, the best practices surrounding usage of Context
weren't quite worked out. We defined our own type to make usage easier.
As this packaged was used elsewhere, it make it more and more
challenging to integrate with the forked `Context` type. Now that it is
available in the standard library, we can just use that one directly.
To make usage more consistent, we now use `dcontext` when referring to
the distribution context package.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
Under certain circumstances, the use of `StorageDriver.GetContent` can
result in unbounded memory allocations. In particualr, this happens when
accessing a layer through the manifests endpoint.
This problem is mitigated by setting a 4MB limit when using to access
content that may have been accepted from a user. In practice, this means
setting the limit with the use of `BlobProvider.Get` by wrapping
`StorageDriver.GetContent` in a helper that uses `StorageDriver.Reader`
with a `limitReader` that returns an error.
When mitigating this security issue, we also noticed that the size of
manifests uploaded to the registry is also unlimited. We apply similar
logic to the request body of payloads that are full buffered.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
In some conditions, regulator.exit may not send a signal to blocked
regulator.enter.
Let's assume we are in the critical section of regulator.exit and r.available
is equal to 0. And there are three more gorotines. One goroutine also executes
regulator.exit and waits for the lock. Rest run regulator.enter and wait for
the signal.
We send the signal, and after releasing the lock, there will be lock
contention:
1. Wait from regulator.enter
2. Lock from regulator.exit
If the winner is Lock from regulator.exit, we will not send another signal to
unlock the second Wait.
Signed-off-by: Oleg Bulatov <obulatov@redhat.com>
A previous inspection of the code surrounding zero-length blobs led to
some interesting question. After inspection, it was found that the hash
was indeed for the empty string (""), and not an empty tar, so the code
was correct. The variable naming and comments have been updated
accordingly.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
The registry uses partial Named values which the named parsers
no longer support. To allow the registry service to continue
to operate without canonicalization, switch to use WithName.
In the future, the registry should start using fully canonical
values on the backend and WithName should no longer support
creating partial values.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
`app.driver.List` on `"/"` is very expensive if registry contains significant amount of images. And the result isn't used anyways.
In most (if not all) storage drivers, `Stat` has a cheaper implementation, so use it instead to achieve the same goal.
Signed-off-by: yixi zhang <yixi@memsql.com>
Modify manifest builder so it can be used to build
manifests with different configuration media types.
Rename config media type const to image config.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
See #2077 for background.
The PR #1438 which was not reviewed by azure folks basically introduced
a race condition around uploads to the same blob by multiple clients
concurrently as it used the "writer" type for PutContent(), introduced in #1438.
This does chunked upload of blobs using "AppendBlob" type, which was not atomic.
Usage of "writer" type and thus AppendBlobs on metadata files is currently not
concurrency-safe and generally, they are not the right type of blob for the job.
This patch fixes PutContent() to use the atomic upload operation that works
for uploads smaller than 64 MB and creates blobs with "BlockBlob" type. To be
backwards compatible, we query the type of the blob first and if it is not
a "BlockBlob" we delete the blob first before doing an atomic PUT. This
creates a small inconsistency/race window "only once". Once the blob is made
"BlockBlob", it is overwritten with a single PUT atomicallly next time.
Therefore, going forward, PutContent() will be producing BlockBlobs and it
will silently migrate the AppendBlobs introduced in #1438 to BlockBlobs with
this patch.
Tested with existing code side by side, both registries with and without this
patch work fine without breaking each other. So this should be good from a
backwards/forward compatiblity perspective, with a cost of doing an extra
HEAD checking the blob type.
Fixes#2077.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
Golint now checks for new lines at the end of go error strings,
remove these unneeded new lines.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Updating to a recent version of Azure Storage SDK to be
able to patch some memory leaks through configurable HTTP client
changes which were made possible by recent patches to it.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
The current code determines the header order for the
"string-to-sign" payload by sorting on the concatenation
of headers and values, whereas it should only happen on the
key.
During multipart uploads, since `x-amz-copy-source-range` and
`x-amz-copy-source` headers are present, V2 signatures fail to
validate since header order is swapped.
This patch reverts to the expected behavior.
Signed-off-by: Pierre-Yves Ritschard <pyr@spootnik.org>
Driver was passing connections by copying. Storing
`swift.Connection` as pointer to fix the warnings.
Ref: #2030.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
In GetContent() we read the bytes from a blob but do not close
the underlying response body.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
To allow generic manifest walking, we define an interface method of
`References` that returns the referenced items in the manifest. The
current implementation does not return the config target from schema2,
making this useless for most applications.
The garbage collector has been modified to show the utility of this
correctly formed `References` method. We may be able to make more
generic traversal methods with this, as well.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
