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>
If the client doesn't support manifest lists, the registry will
rewrite a manifest list into the old format. The Docker-Content-Digest
header should be updated in this case.
Signed-off-by: Oleg Bulatov <oleg@bulatov.me>
When get manifest, the handler will try to retrieve it from storage driver. When storage driver is cloud storage, it can fail due to various reasons even if the manifest exists
(like 500, 503, etc. from storage server). Currently manifest handler blindly return 404 which can be confusing to user.
This change will return 404 if the manifest blob doesn't exist, and return 500 UnknownError for all other errors (consistent with the behavior of other handlers).
Signed-off-by: Yu Wang (UC) <yuwa@microsoft.com>
Once upon a time, we referred to manifests and images interchangably.
That simple past is no more. As we grow, we update our nomenclature and
so follows our code.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
