The preceding recipe, Creating a pipeline using Auto DevOps, showed you how to take advantage of the functionality of Auto DevOps to simplify the creation of pipelines.
In step 2, after you run the pipeline, GitLab Auto DevOps saves you time and effort from creating the stages and jobs manually when no .gitlab-ci.yml files are found in the project. This file is created by GitLab and provides CI/CD configuration for all the projects that don't have one.
If you like to use the .gitlab-ci.yaml file instead, disable Auto DevOps and use the Set up CI/CD button on your project to create your GitLab CI/CD YAML file from a template. Follow the link regarding the Creating a simple .gitlab-ci.yaml file instructions in the See also section to learn more about creating the YAML file.
During step 3, Auto DevOps uses Herokuish Buildpacks, a tool for emulating Heroku build and runtime tasks in containers. By using Herokuish, GitLab detects the language your project is written in and automatically creates the pipeline.