Pattern Matching for rules parameter Gitlab CI - regex

Question

I am trying to make use of the rules: parameter to make a job only appear in a pipeline if specified users did the push. I dont want to define the list of users for each job, so I have the following global variable:
variables:
USER_LIST: "user1 user2 user3"
and in the job, I have the following:
rules:
- if '$USER_LIST =~ /$GITLAB_USER_LOGIN/'
when: on_success
- when: never
This does not appear to be working, as I suspect the regex pattern being used is not being replaced by the variable, and using $GITLAB_USER_LOGIN as the search string. If I use an explicit search:
rules:
- if '$USER_LIST =~ /user1/'
when: on_success
- when: never
then the pattern matches just fine.
NOTE: I am aware that GITLAB_USER_LOGIN is a protected variable. I get the same problem with GITLAB_USER_EMAIL too.
So the question is, how can I put a GITLAB predifined variable into a string that will be used for pattern matching?

Answer 1

You are using a variable and not a regular expression in your rule. So you don't need the slashes around the $GITLAB_USER_LOGIN variable. Try something like this:
rules:
- if '$USER_LIST =~ $GITLAB_USER_LOGIN'

Answer 2

I have more or less the same problem setup. The issues mentioned in the comments were addressed in 15.1, see https://docs.gitlab.com/ee/ci/jobs/job_control.html#store-the-regex-pattern-in-a-variable.
Nevertheless '$USER_LIST =~ /$GITLAB_USER_LOGIN/' still doesn't work. Also, if you define a variable like pattern: /$GITLAB_USER_LOGIN/ and use that in the way described in the documentation, it doesn't work.
'$USER_LIST =~ $pattern'
What works, but isn't the solution to your or my problem is defining pattern with a fixed pattern, like pattern: /user1/. Then it works if used like this:
'$USER_LIST =~ $pattern'
But obviously, I want to use the actual user, that tries to create a pipeline.
What works on my instance (15.4) is this:
'$GITLAB_USER_LOGIN =~ $USER_LIST'
I have no idea why, cos in my opinion this is no behaviour suggested by the documentation. I looked around in several places and found no documented examples of this use, but it works.
This job gets created with a delayed start:
variables:
pattern: "user"
string: "this contains user and other stuff"
show-env:
stage: env
tags:
- ops
rules:
- if: $pattern =~ $string
when: delayed
start_in: 15m
- when: always
script:
- env
And if you remove user from string and push it again, it gets executed right away.
And it also works when I define USERLIST in the project ci/cd variables and test that against $GITLAB_USER_LOGIN.

Answer 3

The documentation shows that the content matching regex should look like this:
$VARIABLE =~ /^content.*/
for your code you need to add ^ and .*:
rules:
- if '$USER_LIST =~ /^user1.*/'
when: on_success
- when: never

Answer 4

My workaround is to build an dynamic-child-pipeline where the variable within pattern already evaluated and inserted as constant string.