How can caching and artifacts speed up Trunk-based development on GitLab CI?

Trunk-based development (TBD) in GitLab CI streamlines the collaboration between developers by enabling frequent integration of code changes into a central trunk or main branch. Utilizing caching and artifacts can significantly enhance the efficiency of this process by reducing build times and optimizing resource usage.

Caching allows GitLab CI to store dependencies and build outputs, so that subsequent builds do not need to fetch the same resources repeatedly. This leads to faster build stages, enabling developers to push their changes more frequently. On the other hand, artifacts are the output of the build process that can be shared between different jobs in a pipeline. By storing and reusing these artifacts, teams can avoid redundant computations and enhance the development workflow.

Here’s a basic example of a GitLab CI configuration file that demonstrates the use of caching and artifacts:

# .gitlab-ci.yml
stages:
  - build
  - test

cache:
  paths:
    - vendor/

build_job:
  stage: build
  script:
    - composer install
  artifacts:
    paths:
      - build/

test_job:
  stage: test
  script:
    - vendor/bin/phpunit --testsuite Unit