Bitbucket self-hosted runner user

[Svetlozar Petkov]

I looked over the internet, but I could not find the answer to this question.

What user does the bitbucket runner use when installed in a linux server ?

For example gitlab uses the gitlab-runner user in bitbucket how can you define which user the runner uses and is it possible to do so ? The question is for both docker and linux shell.

[Patrik S · Accepted solution]

Hello @Svetlozar Petkov and thank you for reaching out to the community!

• For Linux docker runner :
  
  When installing docker in your machine, the docker daemon by default uses the root user. If you want to run docker daemon in rootless mode, you will need to install docker following the instructions of Run docker daemon as non-root user.
  
  As for the user inside the runner container, it's also using the root user as default.
• For the Linux Shell runner : 
  
  The user that executed the runner start script. It will usually be the user of the terminal session where you executed the ./start.sh pre-defined script you received when creating the runner.

Thank you, @Svetlozar Petkov !
Patrik S

[Svetlozar Petkov]

Thank you for the response. This cleared things up nicely!

[iamnst]

Hi @Patrik S,

I have been exploring ways to run self-hosted Bitbucket runners without requiring privileged mode (privileged: true). Specifically, I attempted to use the docker:23.0-dind-rootless image in combination with the Bitbucket runner image (docker-public.packages.atlassian.com/sox/atlassian/bitbucket-pipelines-runner) as an alternative to the docker:23.0.0-dind image. Unfortunately, this led to various errors. Additionally, I tested integrating the Kaniko image alongside the Bitbucket runner image, but encountered Java-related errors during the process.

Given this, I have the following questions:

1. Is there a recommended approach to securely build container images in Bitbucket using self-hosted runners, without needing privileged mode enabled?
2. Does Bitbucket officially support tools such as Kaniko or Podman to allow for daemonless builds, thus eliminating the requirement for Docker daemon root privileges?

I noticed that GitLab provides clear documentation on how to use Kaniko for secure, daemonless builds (e.g., GitLab Documentation on Kaniko), but I was unable to find similar resources within the Bitbucket community. Having detailed guidance on this topic would be extremely helpful for Bitbucket users as well.

I would greatly appreciate your guidance or any best practices for addressing this use case.

Thank you for your time and assistance.