Add support for fd:// for socket activation

[afbjorklund]

Used go-systemd code from moby/moby daemon

Only added buildkitd --addr fd:// for now.

Closes #1923

[tonistiigi]

You need to run ./hack/update-vendor

[AkihiroSuda]

Can we have documented this in README?

[afbjorklund]

Can we have documented this in README?

Sure. I didn't get any feedback on what you wanted to do with the systemd units, in general ?

Just stick them in some "contrib/init" or something, or where should such files be located ?

But can write some general text for the README.md, like the issue text (or like the tcp://)

[AkihiroSuda]

Maybe examples/systemd

[tonistiigi]

cross is failing

#65 117.7 # github.com/coreos/go-systemd/v22/activation
#65 117.7 vendor/github.com/coreos/go-systemd/v22/activation/files.go:57:22: cannot use fd (type int) as type syscall.Handle in argument to syscall.CloseOnExec
#65 ...

[afbjorklund]

cross is failing

systemd on windows ? probably should just skip it there

(didn't know you were building buildkitd for Windows)

[afbjorklund]

I think the test failure is unrelated to this ?

2020-12-29T08:49:53.9205191Z --- FAIL: TestClientGatewayIntegration/TestClientGatewayContainerMounts/worker=containerd-snapshotter-stargz (16.31s)

2020-12-29T08:52:48.5944387Z FAIL github.com/moby/buildkit/client 251.113s

Probably more related to 2f4c15d

[AkihiroSuda]

LGTM but please squash commits, it will also restart CI

[afbjorklund]

LGTM but please squash commits, it will also restart CI

Squashed and rebased, as requested.

Have you considered adding an idle timeout to buildkitd ?

So that it will shut down the service automatically, when done.
i.e. when all builds are completed, only listener socket remains

[tonistiigi]

So that it will shut down the service automatically, when done.
i.e. when all builds are completed, only listener socket remains

Not against it if we can guarantee that there is no race between daemon shutting down and a new request coming in.

[liveDC]

Merging