How do I get the SHA / Container ID of failed builds

[sindre-nistad]

• I have tried with the latest version of my channel (Stable or Edge)
• I have uploaded Diagnostics
• Diagnostics ID: 186430DE-AC01-457C-A70E-BEDB4F520049/20201020074455

Expected behavior

Be able to find the container ID of failed builds, so that I can log enter them interactively, and debug them.

Actual behavior

=> ERROR [build x/n] RUN <failed command>

Information

• macOS Version: 10.15.7

Diagnostic logs

Docker for Mac: version...

Steps to reproduce the behavior

1. ...
2. ...

[stephen-turner]

I'm not sure I understand the question. If the build failed, there is no container to inspect.

[sindre-nistad]

There should be an intermediate container. At least it was earlier (and may still be in the stable release).

From "Examples/Build with PATH"

$ docker build .

Uploading context 10240 bytes
Step 1/3 : FROM busybox
Pulling repository busybox
 ---> e9aa60c60128MB/2.284 MB (100%) endpoint: https://cdn-registry-1.docker.io/v1/
Step 2/3 : RUN ls -lh /
 ---> Running in 9c9e81692ae9
total 24
drwxr-xr-x    2 root     root        4.0K Mar 12  2013 bin
drwxr-xr-x    5 root     root        4.0K Oct 19 00:19 dev
drwxr-xr-x    2 root     root        4.0K Oct 19 00:19 etc
drwxr-xr-x    2 root     root        4.0K Nov 15 23:34 lib
lrwxrwxrwx    1 root     root           3 Mar 12  2013 lib64 -> lib
dr-xr-xr-x  116 root     root           0 Nov 15 23:34 proc
lrwxrwxrwx    1 root     root           3 Mar 12  2013 sbin -> bin
dr-xr-xr-x   13 root     root           0 Nov 15 23:34 sys
drwxr-xr-x    2 root     root        4.0K Mar 12  2013 tmp
drwxr-xr-x    2 root     root        4.0K Nov 15 23:34 usr
 ---> b35f4035db3f
Step 3/3 : CMD echo Hello world
 ---> Running in 02071fceb21b
 ---> f52f38b7823e
Successfully built f52f38b7823e
Removing intermediate container 9c9e81692ae9
Removing intermediate container 02071fceb21b

In my case, one of the RUN commands fails, and I'd like to run docker run --rm -it <container ID> bash.

Let's say, that in the above example CMD echo Hello world fails for some reason (or that it was a RUN command instead).
Then I'd like to run docker run --rm -it b35f4035db3f sh in order to interactively inspect the content of the container, and try different commands.
This is especially useful when compiling some software, and the configuring, or compilation fails.

[stephen-turner]

Apologies, I didn't know that was possible.

We recently switched from legacy build to buildkit, which may explain the difference. If you switch back to legacy build in Preferences-Engine, do you get the behaviour you were hoping for?

[sindre-nistad]

Yes.

Though, I'd like to have the option for see the container ID in BuildKit as well (docker build --verbose ., or docker build --show-ids ., or something similar).

For one thing, switching back takes some time (i.e. restarting Docker), and the image has to be rebuilt (at least, that's what happened now).

[stephen-turner]

OK, I'm going to move this ticket into the buildx repo as that code is all upstream of us.

[tonistiigi]

Follow updates on this in moby/buildkit#1472 . Current best workaround is to set --target to point to a previous command.