Prev Next

DevOps / GitLab CI Basics Interview Questions

What is the 'extends' keyword and how does it enable job templates?

The extends keyword lets one job inherit configuration from another job (or a hidden job used as a template). This reduces duplication and keeps the pipeline DRY (Don't Repeat Yourself).

# Define a hidden job template (starts with .)
.base-deploy:
  image: alpine:latest
  before_script:
    - apk add --no-cache curl
    - echo "Logging into registry..."
  after_script:
    - echo "Deployment complete"
  rules:
    - if: $CI_COMMIT_BRANCH == "main"

# Jobs extend the template
deploy-staging:
  extends: .base-deploy
  script:
    - ./deploy.sh staging
  environment:
    name: staging

deploy-production:
  extends: .base-deploy
  script:
    - ./deploy.sh production
  environment:
    name: production
  rules:                          # overrides the template rules
    - if: $CI_COMMIT_TAG
      when: manual

# extends with multiple parents (array form)
.logging:
  after_script:
    - send-logs.sh

my-job:
  extends:
    - .base-deploy
    - .logging          # merges config from both (later parent wins on conflict)

Merge behaviour: when a job extends a template, YAML hashes are merged deeply. Arrays (like script, rules) in the child job replace (not append to) the parent's arrays. A job can extend multiple templates by providing an array - conflicts are resolved with the last-listed parent winning, then the child overriding all.

How does GitLab CI resolve conflicts when a job overrides a field from its extended template?
What naming convention is used for template jobs that should not run on their own?

More Related questions...

What is GitLab CI/CD and what problem does it solve? What is the.gitlab-ci.yml file and where must it be placed? What is a GitLab CI/CD pipeline? What are stages in GitLab CI/CD and how do you define them? What is a CI/CD job in GitLab and what are the required keywords? What is a GitLab Runner and what types are available? What is the 'script', 'before_script', and 'after_script' keywords and how do they differ? How do you use the 'image' keyword to specify a Docker environment for a job? What are GitLab CI/CD artifacts and how do you use them? What is the difference between cache and artifacts in GitLab CI? What are GitLab CI/CD variables and what types are available? What are the most important predefined CI/CD variables in GitLab? What are 'rules' in GitLab CI/CD and how do they control when jobs run? What is the difference between 'only/except' and 'rules' in GitLab CI? What is the 'needs' keyword in GitLab CI/CD and what problem does it solve? What is the 'workflow' keyword in GitLab CI and how does it control pipeline creation? What is the 'extends' keyword and how does it enable job templates? What is the 'include' keyword and how do you share CI configuration across projects? What are GitLab environments and how do you define them in CI/CD? What are manual jobs in GitLab CI/CD and how do you configure them? What is the 'allow_failure' keyword and how does it affect pipeline status? How does parallel job execution work in GitLab CI/CD? What are GitLab CI/CD scheduled pipelines and how do you set them up? What are pipeline triggers and how can a pipeline be started without a git push? What is the 'retry' keyword and how do you handle flaky tests in GitLab CI? What is the 'timeout' keyword in GitLab CI and what are the defaults? What is the GitLab Container Registry and how do you use it in CI/CD pipelines? What are 'services' in GitLab CI/CD and how do you use them? What is the 'default' keyword in GitLab CI and how does it reduce duplication? What are YAML anchors and aliases in GitLab CI and how do they reduce duplication? What is a merge request pipeline in GitLab CI and how does it differ from a branch pipeline? What is pipeline caching and how do you configure cache keys? What is the GitLab CI Lint tool and how do you validate a.gitlab-ci.yml file? What are GitLab CI/CD components and how do they differ from includes? What are parent-child pipelines in GitLab CI/CD? What is the 'resource_group' keyword and how does it prevent concurrent deployments? What are GitLab's built-in security scanning templates and how do you enable them? What is the 'GIT_STRATEGY' variable in GitLab CI and what are the options? What are protected branches and protected variables in GitLab CI? What are common reasons a GitLab CI pipeline fails and how do you troubleshoot them?
Show more question and Answers...

Ansible Interview questions

Comments & Discussions

Interviews Questions

About Javapedia.net

Javapedia.net is for Java and J2EE developers, technologist and college students who prepare of interview. Also this site includes many practical examples.

This site is developed using J2EE technologies by Steve Antony, a senior Developer/lead at one of the logistics based company.

Follow Javapedia updates

contact: javatutorials2016[at]gmail[dot]com

Kindly consider donating for maintaining this website. Thanks.

Copyright © 2026, javapedia.net, all rights reserved. · .

DMCA.com Protection Status