Commit e6907243af applied a fix for situations
where the client was configured with API-version negotiation, but did not yet
negotiate a version.
However, the checkVersion() function that was implemented copied the semantics
of cli.NegotiateAPIVersion, which ignored connection failures with the
assumption that connection errors would still surface further down.
However, when using the result of a failed negotiation for NewVersionError,
an API version mismatch error would be produced, masking the actual connection
error.
This patch changes the signature of checkVersion to return unexpected errors,
including failures to connect to the API.
Before this patch:
docker -H unix:///no/such/socket.sock secret ls
"secret list" requires API version 1.25, but the Docker daemon API version is 1.24
With this patch applied:
docker -H unix:///no/such/socket.sock secret ls
Cannot connect to the Docker daemon at unix:///no/such/socket.sock. Is the docker daemon running?
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
We try to perform API-version negotiation as lazy as possible (and only execute
when we are about to make an API request). However, some code requires API-version
dependent handling (to set options, or remove options based on the version of the
API we're using).
Currently this code depended on the caller code to perform API negotiation (or
to configure the API version) first, which may not happen, and because of that
we may be missing options (or set options that are not supported on older API
versions).
This patch:
- splits the code that triggered API-version negotiation to a separate
Client.checkVersion() function.
- updates NewVersionError to accept a context
- updates NewVersionError to perform API-version negotiation (if enabled)
- updates various Client functions to manually trigger API-version negotiation
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Fixes#18864, #20648, #33561, #40901.
[This GH comment][1] makes clear network name uniqueness has never been
enforced due to the eventually consistent nature of Classic Swarm
datastores:
> there is no guaranteed way to check for duplicates across a cluster of
> docker hosts.
And this is further confirmed by other comments made by @mrjana in that
same issue, eg. [this one][2]:
> we want to adopt a schema which can pave the way in the future for a
> completely decentralized cluster of docker hosts (if scalability is
> needed).
This decentralized model is what Classic Swarm was trying to be. It's
been superseded since then by Docker Swarm, which has a centralized
control plane.
To circumvent this drawback, the `NetworkCreate` endpoint accepts a
`CheckDuplicate` flag. However it's not perfectly reliable as it won't
catch concurrent requests.
Due to this design decision, API clients like Compose have to implement
workarounds to make sure names are really unique (eg.
docker/compose#9585). And the daemon itself has seen a string of issues
due to that decision, including some that aren't fixed to this day (for
instance moby/moby#40901):
> The problem is, that if you specify a network for a container using
> the ID, it will add that network to the container but it will then
> change it to reference the network by using the name.
To summarize, this "feature" is broken, has no practical use and is a
source of pain for Docker users and API consumers. So let's just remove
it for _all_ API versions.
[1]: https://github.com/moby/moby/issues/18864#issuecomment-167201414
[2]: https://github.com/moby/moby/issues/18864#issuecomment-167202589
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Unlike a plain `net/http/client.Do()`, requests made through client/request
use the `sendRequest` function, which parses the server response, and may
convert non-transport errors into errors (through `cli.checkResponseErr()`).
This means that we cannot assume that no reader was opened if an error is
returned.
This patch changes various locations where `ensureReaderClosed` was only
called in the non-error situation, and uses a `defer` to make sure it's
always called.
`ensureReaderClosed` itself already checks if the response's body was set,
so in situations where the error was due to a transport error, calling
`ensureReaderClosed` should be a no-op.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Since Go 1.7, context is a standard package. Since Go 1.9, everything
that is provided by "x/net/context" is a couple of type aliases to
types in "context".
Many vendored packages still use x/net/context, so vendor entry remains
for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
