Gitlab CICD - Workflow in include overwriting all variables instead of just adding more

Question

I have a 1 repository that have a test-ci.yml:

stages:
  - build

workflow:
  rules:
    - if $CI_COMMIT_BRANCH == "main"
      variables:
           SOME_VARIABLE: $SOME_PROD_VARIABLE
           SECOND_VARIABLE: $SECOND_PROD_VARIABLE

workflow:
  rules:
    - if $CI_COMMIT_BRANCH == "non-prod"
      variables:
           SOME_VARIABLE: $SOME_NP_VARIABLE
           SECOND_VARIABLE: $SECOND_NP_VARIABLE

build-job:
  stage: build
  script:
    - echo $SOME_VARIABLE
    - echo $SECOND_VARIABLE

2 repository .gitlab-ci.yml:

include:
  - project: 'firstrepo'
    file:
      - 'test-ci.yml'

variables:
  PORT: 5000

workflow:
  rules:
    - if $CI_COMMIT_BRANCH == "non-prod"
      variables:
           SECOND_VARIABLE: $SECOND_NP_VARIABLE

workflow:
  rules:
    - if $CI_COMMIT_BRANCH == "main"
      variables:
           SECOND_VARIABLE: $SECOND_PROD_VARIABLE

i want the second project's workflow to overwrite/add the variables, but it replaces all the variables so $SOME_VARIABLE is None.

Answer 1

According to the configuration merging mechanism in Gitlab CI/CD (https://docs.gitlab.com/ee/ci/yaml/includes.html#merge-method-for-include) workflow rules from the main file (here .gitlab-ci.yml) override the rules from included file:

When the key exists in both A and B, and one of the values is not a hash map, use the value from B.

Here the key is workflow.rules and it is a sequence that exists in both files. In test-ci.yml you effectively have:

workflow:
  rules:
    - if $CI_COMMIT_BRANCH == "main"
      variables:
        SOME_VARIABLE: $SOME_PROD_VARIABLE
        SECOND_VARIABLE: $SECOND_PROD_VARIABLE
    - if $CI_COMMIT_BRANCH == "non-prod"
      variables:
        SOME_VARIABLE: $SOME_NP_VARIABLE
        SECOND_VARIABLE: $SECOND_NP_VARIABLE

And in .gitlab-ci.yml:

workflow:
  rules:
    - if $CI_COMMIT_BRANCH == "non-prod"
      variables:
        SECOND_VARIABLE: $SECOND_NP_VARIABLE
    - if $CI_COMMIT_BRANCH == "main"
      variables:
        SECOND_VARIABLE: $SECOND_PROD_VARIABLE

Upon merging the second definition of rules overrides the first one so SOME_VARIABLE is missing.

I see two possible solutions here:

1. In case both workflows are actually identical and the only difference is the value assigned to SOME_VARIABLE then remove workflow definition from .gitlab-ci.yml and instead define SOME_PROD_VARIABLE and SOME_NP_VARIABLE variables there.
2. In case when you need to modify the workflow rules then you must copy the workflow from test-ci.yml and modify accordingly.