Giltab CI Job stuck because the runner tag value hasn’t been assigned - gitlab-ci

Question

I have a CICD configuration that looks something like this:
.rule_template: &rule_configuration
rules:
- changes:
- file/dev/script1.txt
variables:
DESTINATION_HOST: somehost1
RUNNER_TAG: somerunner1
- changes:
- file/test/script1.txt
variables:
DESTINATION_HOST: somehost2
RUNNER_TAG: somerunner2
default:
tags:
- scripts
stages:
- lint
deploy scripts 1/6:
<<: *rule_configuration
tags:
- ${RUNNER_TAG}
stage: lint
script: |
echo "Add linting here!"
....
In short, which runner to choose depends on which file was changed, hence the runner tag has to be conditionally decided. However, these jobs never execute and the value of never gets assigned as i always get:
This job is stuck because you don't have any active runners online or available with any of these tags assigned to them: ${RUNNER_TAG}
Any idea, what is it this way and what can I do to resolve this?
gitlab-runner --version
Version: 14.7.0
Git revision: 98daeee0
Git branch: 14-7-stable
GO version: go1.17.5
Built: 2022-01-19T17:11:48+0000
OS/Arch: linux/amd64

Answer 1

Tags map jobs to runners. I tag my runners with the type of executor they use, e.g. - shell, docker.
Based on the error message, you do not have any runners with the tag ${RUNNER_TAG}, which means that it is not resolving the variable the way you want it to.
Instead of combining rules like this, make separate jobs for each, and a rule for each to say when to trigger it.

Answer 2

I have faced this issue, and similar issues many times while trying to do some dynamic pipelines for a multi-client environment.
The config you have above should work for your purposes to the best of my knowledge, but since it is not there is another way to accomplish this with trigger jobs.
Create a trigger job for each possible runner tag. You can use extends to reduce the total code required for this.
gitlab-ci.yml
stages:
- trigger
- lint
.trigger:
stage: trigger
trigger:
include:
- local: ./lint-job.yml
strategy: depend
trigger-lint-script1:
extends:
- .trigger
variables:
RUNNER_TAG: somerunner1
rules:
- changes:
- file/dev/script1.txt
trigger-lint-script2:
extends:
- .trigger
variables:
RUNNER_TAG: somerunner2
rules:
- changes:
- file/dev/script2.txt
Create a trigger job with associated rules for each possible tag. This way you can change more than one of the specified files in a single commit with no issues. Define the triggered job in lint-job.yml
lint-job.yml
deploy scripts 1/6:
tags: [$RUNNER_TAG]
stage: lint
script: |
echo "Add linting here!"
There are other ways to accomplish this, but this method is by far the simplest and cleanest for this particular use.