Trigger a child pipeline based on reading flags from a config file

I have a config File: config.yml for each project (repository structure provided at the bottom)

AWS_Deploy_Code: True
Azure_Deploy_Code: False

I want to read the config file and trigger the stages based on the flags within the YAML.

If AWS_Deploy_Code =True then trigger Stage_A

If Azure_Deploy_Code =True then trigger Stage_B

Repository is designed as

|->PROJECT-A
| |-> config.yml
|
|->PROJECT-B
| |-> config.yml

I am able to read the YAML file and save the flags in a .env file. However, I am unable to trigger the specific stage based on the flags from YAML/.env file

You cannot choose between stages, but you can build the rest of the pipeline (Downstream Pipelines) based on the values of config.yml. Therefore you should have one step before to execute the script.

gitlab-ci.yml

generate-config:
  stage: generate
  script: generate-ci-config > generated-config.yml
  artifacts:
    paths:
      - generated-config.yml

child-pipeline:
  stage: execute
  trigger:
    include:
      - artifact: generated-config.yml
        job: generate-config

generate-ci-config

#!/bin/bash
# Some stuff for reading the YAML file
if [[ "$AWS_Deploy_Code" == "True" ]]; then
   cat << EOF
   stages:
     - stage_A
   stage-A:
     stage: stage_A
     script: "echo stage_A"
   EOF
elif [[ "$Azure_Deploy_Code" == "False" ]]; then
   cat << EOF
   stages:
     - stage_B
   stage-B:
     stage: stage_B
     script: "echo stage_B"
   EOF
else
   echo "Error"
fi