These comments were added to enforce using the correct import path for
our packages ("github.com/docker/docker", not "github.com/moby/moby").
However, when working in go module mode (not GOPATH / vendor), they have
no effect, so their impact is limited.
Remove these imports in preparation of migrating our code to become an
actual go module.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Looking in history to learn why this struct existed, shows that this type
was mostly the result of tech-debt accumulating over time;
- originally ([moby@1aa7f13]) most of the request handling was internal;
the [`call()` function][1] would make a request, read the `response.Body`,
and return it as a `[]byte` (or an error if one happened).
- some features needed the statuscode, so [moby@a4bcf7e] added an extra
output variable to return the `response.StatusCode`.
- some new features required streaming, so [moby@fdd8d4b] changed the
function to return the `response.Body` as a `io.ReadCloser`, instead
of a `[]byte`.
- some features needed access to the content-type header, so a new
`clientRequest` method was introduced in [moby@6b2eeaf] to read the
`Content-Type` header from `response.Headers` and return it as a string.
- of course, `Content-Type` may not be the only header needed, so [moby@0cdc3b7]
changed the signature to return `response.Headers` as a whole as a
`http.Header`
- things became a bit unwieldy now, with the function having four (4) output
variables, so [moby@126529c] chose to refactor this code, introducing a
`serverResponse` struct to wrap them all, not realizing that all these
values were effectively deconstructed from the `url.Response`, so now
re-assembling them into our own "URL response", only preserving a subset
of the information available.
- now that we had a custom struct, it was possible to add more information
to it without changing the signature. When there was a need to know the
URL of the request that initiated the response, [moby@27ef09a] introduced
a `reqURL` field to hold the `request.URL` which notably also is available
in `response.Request.URL`.
In short;
- The original implementation tried to (pre-maturely) abstract the underlying
response to provide a simplified interface.
- While initially not needed, abstracting caused relevant information from
the response (and request) to be unavailable to callers.
- As a result, we ended up in a situation where we are deconstructing the
original `url.Response`, only to re-assemble it into our own, custom struct
(`serverResponsee`) with only a subset of the information preserved.
This patch removes the `serverResponse` struct, instead returning the
`url.Response` as-is, so that all information is preserved, allowing callers
to use the information they need.
There is one follow-up change to consider; commit [moby@589df17] introduced
a `ensureReaderClosed` utility. Before that commit, the response body would
be closed in a more idiomatic way through a [`defer serverResp.body.Close()`][2].
A later change in [docker/engine-api@5dd6452] added an optimization to that
utility, draining the response to allow connections to be reused. While
skipping that utility (and not draining the response) would not be a critical
issue, it may be easy to overlook that utility, and to close the response
body in the "idiomatic" way, resulting in a possible performance regression.
We need to check if that optimization is still relevant or if later changes
in Go itself already take care of this; we should also look if context
cancellation is handled correctly for these. If it's still relevant, we could
- Wrap the the `url.Response` in a custom struct ("drainCloser") to provide
a `Close()` function handling the draining and closing; this would re-
introduce a custom type to be returned, so perhaps not what we want.
- Wrap the `url.Response.Body` in the response returned (so, calling)
`response.Body.Close()` would call the wrapped closer.
- Change the signature of `Client.sendRequest()` (and related) to return
a `close()` func to handle this; doing so would more strongly encourage
callers to close the response body.
[1]: 1aa7f1392d/commands.go (L1008-L1027)
[2]: 589df17a1a/api/client/ps.go (L84-L89)
[moby@1aa7f13]: 1aa7f1392d
[moby@a4bcf7e]: a4bcf7e1ac
[moby@fdd8d4b]: fdd8d4b7d9
[moby@6b2eeaf]: 6b2eeaf896
[moby@0cdc3b7]: 0cdc3b7539
[moby@126529c]: 126529c6d0
[moby@27ef09a]: 27ef09a46f
[moby@589df17]: 589df17a1a
[docker/engine-api@5dd6452]: 5dd6452d4d
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
I forgot to include this patch in 96039276b6,
which introduced the encodePlatform, which already decorates the error to
have a `invalid platform:` prefix.
While updating, also be more explicit on no result being returned on error.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Add `Platform` parameter that allows to select a specific platform to
show the history for.
This is a breaking change to the Go client as it changes the signature
of `ImageHistory`.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.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>
