Chapter 3. Customizing GitLab pipelines and rebuilding container images

Procedure

1. Create a directory for the build resources. The location of the directory depends on your role:

   • Platform engineer: If you are rebuilding the image to update the default pipeline for your organization, you may create the directory within the location where you forked the tssc-sample-templates repository. For example, rebuild-image.
   • Developers: If you are rebuilding the image for your own use or a specific project, create a directory in a location outside the organization-wide fork of tssc-sample-templates to avoid conflicts.
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   mkdir rebuild-image

2. Run the following command and copy the container image URL:

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   more ../tssc-sample-templates/skeleton/ci/source-repo/gitlabci/.gitlab-ci.yml
   
   # Example:
   ...
   image: quay.io/redhat-appstudio/rhtap-task-runner:latest
   ...

3. Copy the existing pipeline content locally by running the following command:

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   podman run -v $(pwd):/pwd:z <The_url_you_copied_in_step_2> cp -r /work/rhtap /pwd 

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   This command starts the container using the <the_url_you_copied_in_step_2> image. It then copies the pipeline files from /work/rhtap inside the container to your working directory ($(pwd)). Additionally, if you are not on a system with SELinux enabled (for example, Fedora, RHEL, pr CentOS), remove the :z option in the command to ensure compatibility.

4. Navigate to the rhtap directory and customize the pipelines tasks as required.

5. Create a Dockerfile in the rebuild-image directory and add the following content to include your changes in the container. Additionally, the base image quay.io/redhat-appstudio/rhtap-task-runner:latest is built on ubi/ubi-minimal, which provides a lightweight Universal Base Image (UBI). If you need to install additional software and dependencies, use microdnf. An example command:

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   FROM quay.io/redhat-appstudio/rhtap-task-runner:latest 

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   #Copy the updated pipeline tasks
   
   COPY ./rhtap /work/rhtap 

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   # Example: Install additional software (for example, git)
   RUN microdnf -y install make 

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   Uses the existing rhtap-runner container as the starting point.

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   Copies the updated pipeline tasks from the local rhtap folder into the /work/rhtap directory inside the container.

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   Demonstrates the use of the microdnf to install additional software or dependencies.

6. Build the new container image with the following command:

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   podman build -f Dockerfile -t quay.io/<namespace>/<new_image_name> 

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   -f Dockerfile specifies the Dockerfile to use for the build the container image. The -f flag allows you to explicitly point to the Dockerfile if it’s not named Dockerfile or is located in a different directory. -t quay.io/<namespace>/<new_image_name> assigns a tag (name) to the container image for easy identification.

7. Login to Quay.io and push the updated image:

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   podman login quay.io
   
   # Enter username and password
   
   podman push quay.io/<namespace>/<new_image_name> 

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   This uploads the customized container image to Quay.io, making it available for use in GitLab pipelines.

8. Platform engineer only: Navigate to tssc-sample-templates > skeleton > ci > source-repo > gitlabci > .gitlab-ci.yml file and replace the container image URL with the one you just created. This makes the new container image as the default.

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   image: quay.io/<namespace>/<new_image_name>

9. For developers only: To update the container image just for a single repository in GitLab:

   1. Navigate to the source repository > .gitlab-ci.yaml and replace the container image URL with the one you just created.
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   image: quay.io/<namespace>/<new_image_name>

10. Commit and push the changes to apply the updated pipeline configuration.