Add CI_ENVIRONMENT_ID to CI variables
Description
In my usecase, a python web server will be started in review jobs and currently I use pipeline ID to identify them. The problem is that when new commits arrive, I can't find the pipeline ID of last pipeline of the environment in new pipeline to kill its process. Therefore, a lot of orphaned pipelines are hanging in review server. Environment name and slug can't be used since they are not numerical and can't be used as port number.
Proposal
Add CI_ENVIRONMENT_ID to CI variables.
Links / references
Documentation blurb
(Write the start of the documentation of this feature here, include:
- To be used instead of CI_PIPELINE_ID for assigning ports to pipeline jobs
During implementation, this can then be copied and used as a starter for the documentation.)