how to inject dependencies in gitlab jobs to run terraform?

Question

I have a project with terraform code , to create resource in aws. my gitlab ci file (sample below ) has few jobs . I would like to run before_script section before each job , i.e. validate ,apply. how can i achieve this?

stages:
  - validate
  - plan
  - apply

image:
  name: terraform_image_path

before_script:
  - export AWS_ACCESS_KEY=${AWS_ACCESS_KEY_ID}
  - export AWS_SECRET_ACCESS_KEY=${AWS_SECRET_ACCESS_KEY}
  - rm -rf .terraform
  - terraform --version
  - terraform init

validate:
  stage: validate
  script:
    - terraform validate

plan:
  stage: plan
  script:
    - terraform plan -out $Terraform_Plan
  dependencies:
    - validate
  artifacts:
    paths:
      - $Terraform_Plan

apply:
  stage: apply
  script:
    - terraform apply -input=false $Terraform_Plan
  dependencies:
    - plan
  when: manual
 ....
...

Answer 1

As per the official documenation¹:

Use before_script to define an array of commands that should run before each job’s script commands, but after artifacts are restored.

This is as it suggests in the docs. Your before_script will run before any of the defined jobs.

Here's a minimum working example:

before_script:
  - echo "This is executed before each job"

job1:
  script:
    - echo "This is Job 1"

job2:
  script:
    - echo "This is Job 2"

And the result:

For your reference, here's the repository:

https://gitlab.com/meysam81/before-script-demo/-/pipelines