Add type parameter to /system/df

[rvolosatovs]

- What I did
Add type parameter to /system/df

- How I did it
Internally allow more fine-grained control over choice of objects to compute disk usage from, add types URL parameter.

- How to verify it

$ docker run alpine # or create a container in any other way you prefer
$ curl -s --unix-socket /var/run/docker.sock 'http://localhost/system/df?types=image&type=container' | jq # should see image and container data
$ curl -s --unix-socket /var/run/docker.sock 'http://localhost/system/df?type=container&type=invalid' | jq # should see an error:
{
  "message": "unknown object type: invalid"
}
$ curl -s --unix-socket /var/run/docker.sock 'http://localhost/system/df?type=container' | jq # should see only container data
$ curl -s --unix-socket /var/run/docker.sock 'http://localhost/system/df' | jq # should see data, just like before

- Description for the changelog

/system/df endpoint now supports type URL parameter, which gives control over object types to compute disk usage of

[rvolosatovs]

Blocking #42560

[fredericdalleau]

LGTM

test failing

[rvolosatovs]

Sorry, should have checked CI!

[rvolosatovs]

It seems that there's no way to use the testing approach I chose, since the store is modified in parallel to the test execution unless we use -p=1 like in #42594, which I would rather not do. Is there a simple way to setup the daemon with a custom store for a particular test? Or perhaps some way to acquire a global lock for the duration of the test?

[cpuguy83]

You can setup a separate daemon for the test:

d := daemon.New(t, "--iptables=false")
defer d.Cleanup(t)
d.Start(t) // or d.StartWithBusybox if needed.
defer d.Stop(t)

[rvolosatovs]

You can setup a separate daemon for the test:

d := daemon.New(t, "--iptables=false")
defer d.Cleanup(t)
d.Start(t) // or d.StartWithBusybox if needed.
defer d.Stop(t)

Perfect, I followed this approach!

[rvolosatovs]

Looks like 2 test instances still failed 🤔 . This time it seems to be limited to Windows:

disk_usage_test.go:16: [d9303c6a11edc] failed to start daemon with arguments [--data-root D:\gopath\src\github.com\docker\docker\bundles\tmp\TestDiskUsage\d9303c6a11edc\root --exec-root C:\Windows\TEMP\dxr\d9303c6a11edc --pidfile D:\gopath\src\github.com\docker\docker\bundles\tmp\TestDiskUsage\d9303c6a11edc\docker.pid --userland-proxy=true --containerd-namespace d9303c6a11edc --containerd-plugins-namespace d9303c6a11edcp --containerd /var/run/docker/containerd/containerd.sock --host unix://C:\Windows\TEMP\docker-integration\d9303c6a11edc.sock --debug --storage-driver overlay2 --iptables=false] : protocol not available

That is on d.Start(t, "--iptables=false"). Perhaps --iptables=false is not supported on Windows and that's why it fails? Should we check the OS before adding the flag? Is there an alternative one for Windows?

[rvolosatovs]

Removed --iptables=false flag, since many other tests also don't use it. Added t.Parallel() as well, since we now use a separate daemon.

[rvolosatovs]

Looks like iptables was not the problem:

disk_usage_test.go:18: [d81ab14b1027e] failed to start daemon with arguments [--data-root D:\gopath\src\github.com\docker\docker\bundles\tmp\TestDiskUsage\d81ab14b1027e\root --exec-root C:\Windows\TEMP\dxr\d81ab14b1027e --pidfile D:\gopath\src\github.com\docker\docker\bundles\tmp\TestDiskUsage\d81ab14b1027e\docker.pid --userland-proxy=true --containerd-namespace d81ab14b1027e --containerd-plugins-namespace d81ab14b1027ep --containerd /var/run/docker/containerd/containerd.sock --host unix://C:\Windows\TEMP\docker-integration\d81ab14b1027e.sock --debug --storage-driver overlay2] : protocol not available

It looks like tests that do d.Start are actually skipped on Windows, so I followed the same approach.

[rvolosatovs]

@cpuguy83 @thaJeztah PTAL

tests now implemented

[thaJeztah]

LGTM