Pass multiple custom variables to other jobs - gitlab

Question

Trying to effectively pass multiple custom variables (about 10 of them) to other pipeline jobs through dotenv, by not creating 10x "- echo Var=Var". The custom variables have different values depending if the Environment is Dev,Test,Prod etc (about 8 different environments) as well.
From my understanding I can use child jobs to differentiate between environments, and use extends functionality as a config file to create all the variables for the different environments. Problem is that it's very cumbersome logic to use the bellow code when I’m going to add all the variables for all the environments.
Example code:
#Seperate file
.environment:Test:
variables:
CustomVar_ExtendServerFQDN: 'TestHost'
CustomVar_Datacenter: 'TestDatacenter'
.environment:Dev:
variables:
CustomVar_ExtendServerFQDN: 'DevHost'
CustomVar_Datacenter: 'DevDatacenter'
#Prep file
EnvironmentPrep:Dev:
stage: build
extends: .environment:Dev
script:
- echo "ServerFQDN=$CustomVar_ServerFQDN" >> build.env
- echo "Datacenter=$CustomVar_Datacenter" >> build.env
- echo "GitLab CI/CD | Print all environment variables"
- env
artifacts:
reports:
dotenv: build.env
rules:
- if: '$Environment=="Dev"'
EnvironmentPrep:Test:
stage: build
extends: .environment:Test
script:
- echo "ServerFQDN=$CustomVar_ServerFQDN" >> build.env
- echo "Datacenter=$CustomVar_Datacenter" >> build.env
- echo "GitLab CI/CD | Print all environment variables"
- env
artifacts:
reports:
dotenv: build.env
rules:
- if: '$Environment=="Test"'
#Main job file
MainJob:
stage: deploy
script:
- echo "Main Environment variable is [$Environment] [$Server]"
- echo "GitLab CI/CD | Print all environment variables"
- env
variables:
Environment: 'Test'
With this logic it means 10x "-echo var=$var", in each environment job, total of 80 "-echo var=$var" for the merged YAML.
Is there a more effective logic to make sure the MainJob gets the custom variables retrieved from a build stage job?
I'm looking for something like the bellow example, but I'm not sure how to create the logic or filter on only the custom variables "CustomVar_*" for variable $scriptBlock:
#Seperate file
.environment:Test:
variables:
CustomVar_ExtendServerFQDN: 'TestHost'
CustomVar_Datacenter: 'TestDatacenter'
.environment:Dev:
variables:
CustomVar_ExtendServerFQDN: 'DevHost'
CustomVar_Datacenter: 'DevDatacenter'
EnvironmentPrep:Dev:
stage: build
extends: .environment:Dev
script:
- $scriptBlock >> build.env
artifacts:
reports:
dotenv: build.env
rules:
- if: '$Environment=="Dev"'
EnvironmentPrep:Test:
stage: build
extends: .environment:Test
script:
- $scriptBlock >> build.env
artifacts:
reports:
dotenv: build.env
rules:
- if: '$Environment=="Test"'
MainJob:
stage: deploy
script:
- echo "Main Environment variable is [$Environment] [$Server]"
- echo "GitLab CI/CD | Print all environment variables"
- env
variables:
Environment: 'Test'
scriptBlock: <SOME FILTER LOGIC ON "CustomVar_*">