Introduced in GitLab 8.12.
GitLab 8.12 has a completely redesigned job permissions system. You can find all discussion and all our concerns when choosing the current approach in issue #18994.
Jobs permissions should be tightly integrated with the permissions of a user who is triggering a job.
The reasons to do it like that are:
git push, using the web UI, executing triggers).With the new behavior, any job that is triggered by the user, is also marked with their permissions. When a user does a git push or changes files through the web UI, a new pipeline will be usually created. This pipeline will be marked as created be the pusher (local push or via the UI) and any job created in this pipeline will have the permissions of the pusher.
This allows us to make it really easy to evaluate the access for all projects that have Git submodules or are using container images that the pusher would have access too. The permission is granted only for time that job is running. The access is revoked after the job is finished.
It is important to note that we have a few types of users:
Administrators: CI jobs created by Administrators will not have access to all GitLab projects, but only to projects and container images of projects that the administrator is a member of.That means that if a project is either public or internal users have access anyway, but if a project is private, the Administrator will have to be a member of it in order to have access to it via another project's job.
External users: CI jobs created by external users will have access only to projects to which user has at least reporter access. This rules out accessing all internal projects by default,
This allows us to make the CI and permission system more trustworthy. Let's consider the following scenario:
You are an employee of a company. Your company has a number of internal tools hosted in private repositories and you have multiple CI jobs that make use of these repositories.
You invite a new external user. CI jobs created by that user do not have access to internal repositories, because the user also doesn't have the access from within GitLab. You as an employee have to grant explicit access for this user. This allows us to prevent from accidental data leakage.
A unique job token is generated for each job and it allows the user to access all projects that would be normally accessible to the user creating that job.
We try to make sure that this token doesn't leak by:
However, this brings a question about the Runners security. To make sure that this token doesn't leak, you should also make sure that you configure your Runners in the most possible secure way, by avoiding the following:
privileged mode is risky if the machines are re-used.shell executor since jobs run on the same machine.By using an insecure GitLab Runner configuration, you allow the rogue developers to steal the tokens of other jobs.
job triggers do not support the new permission model. They continue to use the old authentication mechanism where the CI job can access only its own sources. We plan to remove that limitation in one of the upcoming releases.
In versions before GitLab 8.12, all CI jobs would use the CI Runner's token to checkout project sources.
The project's Runner's token was a token that you could find under the project's Settings > CI/CD Pipelines and was limited to access only that project. It could be used for registering new specific Runners assigned to the project and to checkout project sources. It could also be used with the GitLab Container Registry for that project, allowing pulling and pushing Docker images from within the CI job.
GitLab would create a special checkout URL like:
https://gitlab-ci-token:<project-runners-token>/gitlab.com/gitlab-org/gitlab-ce.gitAnd then the users could also use it in their CI jobs all Docker related commands to interact with GitLab Container Registry. For example:
docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN registry.gitlab.comUsing single token had multiple security implications:
All the above led to a new permission model for jobs that was introduced with GitLab 8.12.
With the new job permissions model, there is now an easy way to access all dependent source code in a project. That way, we can:
Below you can see the prerequisites needed to make use of the new permissions model and how that works with Git submodules and private Docker images hosted on the container registry.
With the new permissions model in place, there may be times that your job will fail. This is most likely because your project tries to access other project's sources, and you don't have the appropriate permissions. In the job log look for information about 403 or forbidden access messages.
In short here's what you need to do should you encounter any issues.
As an administrator:
As a user:
To properly configure submodules with GitLab CI, read the Git submodules documentation.
With the update permission model we also extended the support for accessing Container Registries for private projects.
Notes:
image: directive to not work with private projects automatically and it needs to be configured manually on Runner's host with a predefined account (for example administrator's personal account with access token created explicitly for this purpose). This issue is resolved with latest changes in GitLab Runner 1.8 which receives GitLab credentials with build data.Your jobs can access all container images that you would normally have access to. The only implication is that you can push to the Container Registry of the project for which the job is triggered.
This is how an example usage can look like:
test:
script:
- docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN $CI_REGISTRY
- docker pull $CI_REGISTRY/group/other-project:latest
- docker run $CI_REGISTRY/group/other-project:latest