Kraft can not run multiple program at one time

[bettermultiply]

Describe the bug

When I try to run two program at the same time , it failed and report below message to me:

 i  using arch=x86_64 plat=qemu
<!> building rootfs via Dockerfile                                                                                                                                              x86_64 [5.9s]
 i  creating ephemeral buildkit container
 W  could not connect to BuildKit client '' is BuildKit running?
 W  
 W  By default, KraftKit will look for a native install which
 W  is located at /run/buildkit/buildkit.sock.  Alternatively, you
 W  can run BuildKit in a container (recommended for macOS users)
 W  which you can do by running:
 W  
 W    docker run --rm -d --name buildkit --privileged moby/buildkit:v0.20.0
 W  
 W  Depending on your container runtime, you should connect to Buildkit via:
 W  
 W    export KRAFTKIT_BUILDKIT_HOST=docker-container://buildkit # for docker
 W  or
 W    export KRAFTKIT_BUILDKIT_HOST=podman-container://buildkit # for podman
 W  
 W  For more usage instructions visit: https://unikraft.org/buildkit
 W  
 E  creating buildkit container: start container: started hook: wait until ready: container ex ited with code 1
 E  creating buildkit container: start container: started hook: wait until ready: container exited with code 1

And the error also happened when I use -p option of kraft run. However, if I use command kraft remove my_machine, and use kraft run -p ...... instantly(not the same time), this error also happened. If I wait for a few seconds, everything went well. So I think the reason is remove hasn't finished, so that produce a same situation run two program at the same time.

Steps to reproduce

1. Choose one program that do not exit directly.(e.g. add sleep to catalog/helloworld), and run the following command:

kraft run .

^Z

bg

kraft run .

git clone git@github.com:unikraft/catalog.git

cd catalog/example/http-c

kraft run -p 8080:8080 .

^Z

bg

kraft remove my_machine

kraft run -p 8081:8081 .

Expected behavior

error happened.

KraftKit version

0.11.6

Which architectures were you using or does this bug affect?

No response

Which operating system were you using or does this bug affect?

No response

Relevant log output

i  using arch=x86_64 plat=qemu
<!> building rootfs via Dockerfile                                                                                                                                              x86_64 [5.9s]
 i  creating ephemeral buildkit container
 W  could not connect to BuildKit client '' is BuildKit running?
 W  
 W  By default, KraftKit will look for a native install which
 W  is located at /run/buildkit/buildkit.sock.  Alternatively, you
 W  can run BuildKit in a container (recommended for macOS users)
 W  which you can do by running:
 W  
 W    docker run --rm -d --name buildkit --privileged moby/buildkit:v0.20.0
 W  
 W  Depending on your container runtime, you should connect to Buildkit via:
 W  
 W    export KRAFTKIT_BUILDKIT_HOST=docker-container://buildkit # for docker
 W  or
 W    export KRAFTKIT_BUILDKIT_HOST=podman-container://buildkit # for podman
 W  
 W  For more usage instructions visit: https://unikraft.org/buildkit
 W  
 E  creating buildkit container: start container: started hook: wait until ready: container ex ited with code 1
 E  creating buildkit container: start container: started hook: wait until ready: container exited with code 1

[bettermultiply]

Also happened when run sequential

[craciunoiuc]

I think this is unrelated to kraft run actually. It looks like buildkit could not automatically run for whatever reason (used for builds). This usually happens when another instance of buildkit is left hanging for whatever reason.

To check, just run docker container ps and remove it if there.

To be safer, and to cache builds, you can just use the 2 commands suggested by the warning (the docker run + the export).

Let me know if this works/fixes it for you.

[craciunoiuc]

@bettermultiply did you get a chance to retry?

[bettermultiply]

Sorry for the delayed response. I've been quite busy recently and forgot to reply to this issue. I've tried the approach you mentioned, and following the warning instructions does allow multiple examples/http-c instances to run simultaneously, which resolves my problem.

However, I believe this is still related to kraft run. Why can't we solve this directly through kraft itself, rather than having to run buildkit independently and set environment variables? I think being able to run multiple instances simply by using kraft run repeatedly would be more intuitive from a tool usability perspective.

[craciunoiuc]

In the default case it should work. As you can see in the logs image, the error is actually in the build step, so more related to kraft build than kraft run. I think in your case what happens is that you have a docker alternative installed (am I correct?) with which kraft does not know to directly interact and spawn containers like docker.

[craciunoiuc]

Notice other people reporting issues related to podman for examples 😔

#2180

[bettermultiply]

Oh, I am sorry for focus the problem on kraft run instead if kraft build

I think in your case what happens is that you have a docker alternative installed (am I correct?) with which kraft does not know to directly interact and spawn containers like docker.

Howerve, as far as I know, I only installed docker and without podman, singularity or lxc/lxd🥲.

[craciunoiuc]

Hmm, okay. I think I also saw this when running multiple builds at the same time.

I'll do some more tests and come back. Thanks for the info