Here’s a curated set of 30 most frequently asked real-world questions about GitLab CI/CD pipeline automation, with clear and concise answers — perfect for training sessions or real-world use:

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✅ Top 30 GitLab Pipeline Automation Questions & Answers

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1. What is the difference between needs and dependencies in GitLab CI?

• needs: Controls execution order (jobs run as soon as dependencies finish), enables parallelism.
• dependencies: Controls artifact download but doesn’t affect execution order.

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2. Can a single job be reused in multiple stages?

• No, a job can only belong to one stage. You can replicate logic using YAML anchors or templates.

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3. How to conditionally run a job only for merge requests?

rules:
  - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
Code language: JavaScript (javascript)

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4. How to run jobs only on a specific branch like main or dev?

only:
  - main

Or use:

rules:
  - if: '$CI_COMMIT_BRANCH == "main"'
Code language: JavaScript (javascript)

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5. How to cache dependencies between jobs?

cache:
  paths:
    - node_modules/

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6. How to share artifacts between jobs?

Use artifacts and dependencies:

job1:
  script: make build
  artifacts:
    paths: [build/]

job2:
  script: deploy
  dependencies: [job1]
Code language: CSS (css)

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7. How to trigger another project’s pipeline?

trigger:
  project: my-group/another-project
  branch: main

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8. How to create a manual approval job in a pipeline?

when: manual
Code language: HTTP (http)

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9. How to run a job only when a tag is pushed?

only:
  - tags

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10. Can we define multiple .gitlab-ci.yml files?

• Yes, use the include: keyword to import local, remote, or project-specific YAML files.

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11. How to define environment-specific jobs (dev, staging, prod)?

rules:
  - if: '$CI_ENVIRONMENT_NAME == "staging"'
Code language: JavaScript (javascript)

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12. How to use custom variables in GitLab CI?

Define in UI or .gitlab-ci.yml:

variables:
  DEPLOY_ENV: "prod"
Code language: JavaScript (javascript)

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13. How to use matrix builds in GitLab?

parallel:
  matrix:
    - VARIANT: [debug, release]
Code language: CSS (css)

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14. How to run a job only if certain files changed?

rules:
  - changes:
      - src/**/*
Code language: CSS (css)

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15. How to skip pipeline for a commit?

Use [ci skip] in commit message.

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16. What is allow_failure: true used for?

It lets a job fail without failing the whole pipeline.

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17. How to handle secrets or credentials securely?

Store them as CI/CD variables in GitLab UI (masked and protected if needed).

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18. What is the purpose of before_script and after_script?

• before_script: runs before the main job script.
• after_script: runs after the main job script (even on failure).

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19. How to make a job retry on failure?

retry: 2
Code language: HTTP (http)

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20. What is artifacts:expire_in used for?

Sets how long GitLab retains the artifact:

artifacts:
  expire_in: 1 week

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21. What is the role of stages in GitLab CI?

Defines the pipeline flow. Jobs in the same stage run in parallel; stages run sequentially.

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22. How to conditionally run a job on a variable value?

rules:
  - if: '$DEPLOY_ENV == "prod"'
Code language: JavaScript (javascript)

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23. How to disable a job temporarily?

Add:

when: never
Code language: HTTP (http)

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24. How to run a job only when another job fails?

when: on_failure
Code language: HTTP (http)

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25. How to visualize job dependencies (DAG)?

Use needs: to define dependencies and GitLab will show it in pipeline graph view.

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26. Can you trigger child pipelines?

Yes, using:

trigger:
  include: child-pipeline.yml
Code language: CSS (css)

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27. How to control concurrency in pipelines?

Use resource_group: to ensure mutual exclusion:

resource_group: deploy-prod
Code language: HTTP (http)

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28. How to limit job execution time?

timeout: 15 minutes
Code language: HTTP (http)

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29. How to use GitLab CI templates (SAST, DAST, etc.)?

include:
  - template: Security/SAST.gitlab-ci.yml
Code language: PHP (php)

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30. How to pass data between jobs?

Use:

• artifacts (for file data)
• cache (for shared folders)
• CI/CD variables (for text/values)

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31 To copy artifacts from two separate jobs into a single common directory, you need to follow these steps in GitLab CI/CD:

Combine artifacts from job1 and job2 into a common directory in job3.

stages:
  - build
  - merge

job1:
  stage: build
  script:
    - echo "Job 1 output" > job1.txt
  artifacts:
    paths:
      - job1.txt

job2:
  stage: build
  script:
    - echo "Job 2 output" > job2.txt
  artifacts:
    paths:
      - job2.txt

job3:
  stage: merge
  needs:
    - job: job1
      artifacts: true
    - job: job2
      artifacts: true
  script:
    - mkdir merged
    - cp job1.txt merged/
    - cp job2.txt merged/
    - ls -la merged
  artifacts:
    paths:
      - merged/
Code language: PHP (php)

32 .

To copy artifacts from two jobs into a common directory in GitLab CI, you can use artifacts along with the dependencies or needs keyword to make artifacts available to a third job that merges them.

✅ Goal:

You have:

• job1 and job2 that create artifacts
• merge_job that collects them into a shared directory (e.g., merged-artifacts/)

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✅ Example .gitlab-ci.yml

stages:
  - build
  - merge

job1:
  stage: build
  script:
    - echo "Job 1 output" > file1.txt
  artifacts:
    paths:
      - file1.txt

job2:
  stage: build
  script:
    - echo "Job 2 output" > file2.txt
  artifacts:
    paths:
      - file2.txt

merge_job:
  stage: merge
  needs: [job1, job2]
  script:
    - mkdir -p merged-artifacts
    - cp job1/file1.txt merged-artifacts/
    - cp job2/file2.txt merged-artifacts/
    - echo "Merged artifacts:"
    - ls -l merged-artifacts
  dependencies:
    - job1
    - job2
  artifacts:
    paths:
      - merged-artifacts/
Code language: PHP (php)

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