Here are the jobs in the pipeline, following the order as defined in the ‘stages’ section of the .gitlab-ci.yml file;
getsquid_vars: This job fetches the latest Squid
version from GitHub releases. The version is then set as an environment
variable and saved to variables.env file which can be used
in the subsequent stages.hadolint: This job runs Hadolint that performs static
analysis on Dockerfile and reports any issues present.docker-hub-build: This is a build stage that uses
Dockerfile to build an image and pushes to Docker Hub.docker-hub-test: This job conducts a simple curl test
to ensure that the docker image built in the
docker-hub-build job is functioning properly.SquidParseConfig: This job checks Squid configurations
in Docker container by running Squid with -k parse
flag.dive: This job uses the ‘dive’ tool to analyze the
layers of the Docker image created during the
docker-hub-build job.push-docker-hub: This job tags the built Docker image
and pushes it to Docker Hub.chatgpt_analysis: This job runs analysis on the GitLab
CI/CD jobs by using OpenAI’s GPT model. It generates a markdown file
with in-depth explanation of jobs in the pipeline.update_dockerhub_readme: This job updates the Project’s
Docker Hub README with the latest README.md from the Git
repository.For more detailed purposes of each job, please check the attached .gitlab-ci.yml.
For example, docker-hub-build job has a clear
purpose:
docker-hub-build:
stage: Docker-hub-build
image: docker:dind
needs:
- getsquid_vars
before_script:
- docker login -u "$DOCKER_HUB_USER" -p "$DOCKER_HUB_TOKEN" $DOCKER_HUB_REGISTRY
script:
- source variables.env
- docker build --build-arg SQUID_VERSION=$SQUID_VERSION --pull -t $CONTAINER_BUILD_NOPROD_NAME_AMD64 .
- docker push $CONTAINER_BUILD_NOPROD_NAME_AMD64First, Docker executes “docker login”, using the
provided Docker Hub credentials stored as GitLab CI variables.
Next, the Docker image builds using the arguments provided in
“docker build”. Then, the Docker image pushes with the
tag.
Docker command uses the Dockerfile present in the
repository to build the image, while using “SQUID_VERSION” as a build
argument.
This pipeline uses several environment variables, such as “$GITLAB_TOKEN", "$DOCKER_HUB_USER” and “$DOCKER_HUB_TOKEN”. They are stored in GitLab CI’s variables. Variables are stored securely and inject into the CI environment. Note that these variables must be defined before running jobs in the pipeline.
Here’s an example of how environment variables are set and used in the “docker-hub-build” job:
before_script:
- docker login -u "$DOCKER_HUB_USER" -p "$DOCKER_HUB_TOKEN" $DOCKER_HUB_REGISTRY
script:
- source variables.env
- docker build --build-arg SQUID_VERSION=$SQUID_VERSION --pull -t $CONTAINER_BUILD_NOPROD_NAME_AMD64 .
- docker push $CONTAINER_BUILD_NOPROD_NAME_AMD64In this script, “$DOCKER_HUB_USER", "$DOCKER_HUB_TOKEN”, and “$DOCKER_HUB_REGISTRY” are environment variables, provided in GitLab’s setting.
Jobs can have dependencies on each other, as exemplified by the
“needs” keyword in the .gitlab-ci.yml file. The
“needs” keyword allows you to specify that a job depends on
the success of another.
For example, in “push-docker-hub” job:
needs:
- docker-hub-test
- getsquid_varsThis means “push-docker-hub” job only begins if both
“docker-hub-test” and “getsquid_vars” jobs
complete successfully.
The GitLab pipeline will produce several outcomes or artifacts. When
“chatgpt_analysis” job finishes, it generates a markdown
file (“chatgpt_analysis_$(date +%Y%m%d).md”) with in-depth
explanations of jobs in the pipeline.
The “getsquid_vars” job also produces
“variables.env” as an artifact, storing latest Squid
version that’s used by subsequent jobs.
The latest commit e154f33 is labeled “README Auto update
and update last_squid_version [skip ci]”. It updates the README file and
the file “last_squid_version.txt” containing the last known
Squid version. This commit skips CI with “[skip ci]” in the
commit message to prevent unnecessary pipeline triggers.
This commit is used to keep track of the last known Squid version and
prevent rebuilding and re-testing of the Docker image if Squid version
hasn’t changed. This is done by comparing current Squid version with the
version saved in “last_squid_version.txt”.
Project: https://gitlab.com/fredbcode-images/squid Pipeline: https://gitlab.com/fredbcode-images/squid/-/pipelines/2638935734 Docker images: https://hub.docker.com/r/fredbcode