build: print instance being used

[crazy-max]

needs moby/buildkit#3378

Display current builder being used when building. Can help users who need to know the type of builder in use during their build but also for log reports:

$ docker buildx build .
[+] Building 4.8s (11/16)                                                               docker-container:builder2
 => [internal] load build definition from Dockerfile                                                         0.1s
 => => transferring dockerfile: 2.93kB                                                                       0.1s 
 => [internal] load .dockerignore                                                                            0.1s 
 => => transferring context: 45B                                                                             0.1s 
 => resolve image config for docker.io/docker/dockerfile-upstream:1.5.0                                      0.6s
 => CACHED docker-image://docker.io/docker/dockerfile-upstream:1.5.0@sha256:bda6ac9f61f2b676331acfd656a07bc  0.0s
 => => resolve docker.io/docker/dockerfile-upstream:1.5.0@sha256:bda6ac9f61f2b676331acfd656a07bcd55b369143a  0.0s 
 => [internal] load metadata for docker.io/tonistiigi/xx:1.1.2                                               2.4s 
 => [internal] load metadata for docker.io/library/golang:1.19-alpine                                        2.4s 
 => [auth] library/golang:pull token for registry-1.docker.io                                                0.0s
 => [auth] tonistiigi/xx:pull token for registry-1.docker.io                                                 0.0s
 => [xx 1/1] FROM docker.io/tonistiigi/xx:1.1.2@sha256:9dde7edeb9e4a957ce78be9f8c0fbabe0129bf5126933cd35748  0.0s
 => => resolve docker.io/tonistiigi/xx:1.1.2@sha256:9dde7edeb9e4a957ce78be9f8c0fbabe0129bf5126933cd3574888f  0.0s 
 => CANCELED [internal] load build context                                                                   1.5s 
 => => transferring context: 20.57kB                                                                         1.5s 
 => [golatest 1/1] FROM docker.io/library/golang:1.19-alpine@sha256:2381c1e5f8350a901597d633b2e517775eeac7a  0.1s 
 => => resolve docker.io/library/golang:1.19-alpine@sha256:2381c1e5f8350a901597d633b2e517775eeac7a6682be392  0.0s 
ERROR: failed to solve: Canceled: context canceled

$ BUILDKIT_PROGRESS=plain docker buildx build .
#0 building with "builder2" instance using docker-container driver

#1 [internal] load build definition from Dockerfile
#1 transferring dockerfile: 2.93kB 0.0s done
#1 DONE 0.1s

#2 [internal] load .dockerignore
#2 transferring context: 45B 0.0s done
#2 DONE 0.1s

#3 resolve image config for docker.io/docker/dockerfile-upstream:1.5.0
#3 DONE 0.7s

#4 docker-image://docker.io/docker/dockerfile-upstream:1.5.0@sha256:bda6ac9f61f2b676331acfd656a07bcd55b369143ab7db66bdf93b619da3e183
#4 resolve docker.io/docker/dockerfile-upstream:1.5.0@sha256:bda6ac9f61f2b676331acfd656a07bcd55b369143ab7db66bdf93b619da3e183
#4 resolve docker.io/docker/dockerfile-upstream:1.5.0@sha256:bda6ac9f61f2b676331acfd656a07bcd55b369143ab7db66bdf93b619da3e183 0.0s done
#4 CACHED

#5 [internal] load metadata for docker.io/library/golang:1.19-alpine
^C#5 CANCELED

#6 [internal] load metadata for docker.io/tonistiigi/xx:1.1.2
#6 CANCELED
ERROR: failed to solve: Canceled: context canceled

Signed-off-by: CrazyMax crazy-max@users.noreply.github.com

[jedevc]

LGTM 🎉

I'd prefer to replace the progress.Wrap call with a oneOffProgress function just so we don't forget to grep it out when the buildkit PR merges, but not a blocker 👍

[tonistiigi]

I'm not so sure about this. This is not really a progress item, a step that runs as part of the build on a specific time/duration. Is it more like a debug log line?

Maybe if we could fit the instance name on the first line?

[+] Building 29.1s (12/12) FINISHED                           docker-container:buildkit_intance_name
 => [internal] load git source https://github.com/docker/buildx.git                             4.1s 

For progress=plain we should print some summary after the build anyway. Eg. currently we don't tell how long the build took. Maybe we could attach this info then?

[crazy-max]

Is it more like a debug log line?

Yes that's it.

Maybe if we could fit the instance name on the first line?

[+] Building 29.1s (12/12) FINISHED                           docker-container:buildkit_intance_name
 => [internal] load git source https://github.com/docker/buildx.git                             4.1s 

For progress=plain we should print some summary after the build anyway. Eg. currently we don't tell how long the build took. Maybe we could attach this info then?

Sounds good, I will take a look

[jedevc]

LGTM - just a note, this doesn't work with the remote controller, which has it's own progress setup.

However, that's fine if we can open a tracking issue after this merges, I think some more general refactoring of how we do progress is necessary to get a patch that makes more sense for this.