Jenkins: Access job/plugin configuration values inside pipeline - jenkins

Question

I am trying the access the values set on a job's configuration page from within my pipeline. These values are not made available as params, nor are they injected as envvars.
Setup
Jenkins, v2.263.1
GitLab Branch Source plugin, v1.5.3 (link)
Multibranch pipeline job which is pointed to a Gitlab repo
Remote Jenkinsfile Provider, v1.13 (link)
Problem
Ordinarily, one would have a Jenkinsfile in the root of the repo and therefore the scm would be associated with the repo we want to checkout and build. However, in my case the code I want to build is in a different repo to the Jenkinsfile (hence the Remote Jenkinsfile Provider plugin).
This means that I need to checkout the code I wish to build as an explicit step in the pipeline, and to do that I need to know the repo. This repo is, however, already defined in the job config.
The Branch Source plugin does export things like the branch name or merge request number/branch/target into appropriate envvars, but NOT the actual repo.
As this is a multibranch pipeline, I cannot use something like envInject either (multibranch jobs do not provide the option to 'Prepare an environment for the run' as with other jobs)
Goal
I would like to be able to access the server, owner and project fields set in the job config page. Ultimately I could manage with just the project's ssh/http address even.
Is there some clever way of accessing a job's config from within the pipeline?
Thanks for any suggestions!
Reference images

Answer 1

Within the gitlab branch source plugin (and the documentation) you have a lot more information, than just with the normal branch source plugin. there are environment variables for the project like GITLAB_PROJECT_GIT_SSH_URL/GITLAB_PROJECT_GIT_HTTPS_URL for the git source and many more. So far i did not see one for the server, but that would be parse-able our of the URLs.
Within this information, it should be fairly easy to checkout the repository and build it.
As through the process it came clear, that it is needed to also trigger the pipeline manually, and this is normally also possible with variables (not sure about the Remote File plugin). I assume your Jenkinsfile is a groovy script, which opens up a lot of possibilities. You can define variables and use some logic to determine if the env variable or the parameter is used.
pipeline {
parameters {
string(name: 'projectUrl', defaultValue: "")
}
stages {
stage('Prepare') {
steps {
def projectUrl = env.GITLAB_PROJECT_GIT_SSH_URL ?: params.projectUrl
// DO Checkout with projectUrl
}
}
}
}
The only critical thing you have to take into account, is that the multibranch pipeline, has to run once, for each branch or mr - so they detect the variables. Afterwards you can easily trigger it, manually by providing your values.
This allows you, to utilize webhooks for automatic actions, and also allows you to trigger the build manually when ever you like.
Sidenote: if you use the centralized jenkinsfile, for reducing duplication, you might also want to checkout Shared libraries for jenkins.
For completeness, here is a list of all current environment variables added by the jenkins gitlab branch source plugin version 1.5.3 (and only for Push Events - but they are pretty similar in the other event types too)
GITLAB_OBJECT_KIND
GITLAB_AFTER
GITLAB_BEFORE
GITLAB_REF
GITLAB_CHECKOUT_SHA
GITLAB_USER_ID
GITLAB_USER_NAME
GITLAB_USER_EMAIL
GITLAB_PROJECT_ID
GITLAB_PROJECT_ID_2
GITLAB_PROJECT_NAME
GITLAB_PROJECT_DESCRIPTION
GITLAB_PROJECT_WEB_URL
GITLAB_PROJECT_AVATAR_URL
GITLAB_PROJECT_GIT_SSH_URL
GITLAB_PROJECT_GIT_HTTP_URL
GITLAB_PROJECT_NAMESPACE
GITLAB_PROJECT_VISIBILITY_LEVEL
GITLAB_PROJECT_PATH_NAMESPACE
GITLAB_PROJECT_CI_CONFIG_PATH
GITLAB_PROJECT_DEFAULT_BRANCH
GITLAB_PROJECT_HOMEPAGE
GITLAB_PROJECT_URL
GITLAB_PROJECT_SSH_URL
GITLAB_PROJECT_HTTP_URL
GITLAB_REPO_NAME
GITLAB_REPO_URL
GITLAB_REPO_DESCRIPTION
GITLAB_REPO_HOMEPAGE
GITLAB_REPO_GIT_SSH_URL
GITLAB_REPO_GIT_HTTP_URL
GITLAB_REPO_VISIBILITY_LEVEL
GITLAB_COMMIT_COUNT
GITLAB_COMMIT_ID_#
GITLAB_COMMIT_MESSAGE_#
GITLAB_COMMIT_TIMESTAMP_#
GITLAB_COMMIT_URL_#
GITLAB_COMMIT_AUTHOR_AVATAR_URL_#
GITLAB_COMMIT_AUTHOR_CREATED_AT_#
GITLAB_COMMIT_AUTHOR_EMAIL_#
GITLAB_COMMIT_AUTHOR_ID_#
GITLAB_COMMIT_AUTHOR_NAME_#
GITLAB_COMMIT_AUTHOR_STATE_#
GITLAB_COMMIT_AUTHOR_USERNAME_#
GITLAB_COMMIT_AUTHOR_WEB_URL_#
GITLAB_COMMIT_ADDED_#
GITLAB_COMMIT_MODIFIED_#
GITLAB_COMMIT_REMOVED_#
GITLAB_REQUEST_URL
GITLAB_REQUEST_STRING
GITLAB_REQUEST_TOKEN
GITLAB_REFS_HEAD