Following are the jobs in the pipeline, explained as per the order in the ‘stages’ section of the .gitlab-ci.yml file:
hadolint: This job runs in the
Quality stage. The purpose of this job is to lint
Dockerfile to catch potential issues and enforce style
consistency.
getsquid_vars: Within the
Get-version stage, fetches the Squid version from the
GitHub releases page. It then stores the version number and the current
date in a variables.env file which can be used by the
subsequent jobs in the pipeline.
docker-hub-build-arm/docker-hub-build: This job,
run in the Docker-hub-build stage, uses Docker’s
dind (docker in docker) service to build the Docker image
for arm/amd64 architecture. The built image gets pushed to Docker
Hub.
docker-hub-test-arm/docker-hub-test: This
Docker-hub-test stage job verifies whether the previously
built Docker arm/amd64 images work as expected or not.
dive-arm/dive: Run in the
Docker-hub-test stage provides a report about the
efficiency of a Docker image.
push-docker-hub-arm/push-docker-hub: This job,
running in the Docker-hub-pushtag stage, pushes the Docker
image to Docker Hub, as per the given Squid version tag and also the
‘latest’ tag.
chatgpt_analysis: The job generates a markdown
(.md) and HTML report of the pipeline’s functioning using OpenAI’s
ChatGPT, and the generated HTML report is copied to a remote server via
scp.
update_dockerhub_readme: In the
Docs stage, it updates the README.md of the Docker Hub repo
with the README.md file from the GitLab repo.
hadolint --ignore DL3008 DockerfileThis script executes the hadolint tool on the
Dockerfile. hadolint is a linter for Dockerfiles. The
purpose of this command is to help capture best practices, potential
errors, or anti-patterns in the Dockerfile that might otherwise have
been missed. The --ignore flag is used to skip the given
rule (DL3008 in this case, which refers to “Pin versions in
apt-get install”).
export SQUID_VERSION=$(curl -LsXGET https://github.com/squid-cache/squid/releases/latest | grep -m 1 "Release" | cut -d " " -f4 |tr -d 'v')
echo "SQUID_VERSION=$SQUID_VERSION" > variables.env
echo $SQUID_VERSION
sed -i "s/{{SQUID_VERSION}}/$SQUID_VERSION/g" README_template.md
sed -i "s/{{DATE}}/$(date +%Y%m%d)/g" README_template.md
cp README_template.md README.md
git config user.email "fredbcode"
git config user.name "fredbcode"
git add README.md
git commit -m "README Auto update [skip ci]" || true
git push https://$GITLAB_TOKEN@gitlab.com/fredbcode-images/squid.git HEAD:master || trueThis job is responsible for fetching the latest Squid version from GitHub and saving it to the environment variable. Also, it updates README.md with the latest version and push to the master branch if there are changes.
Here building the Docker image happens based on the Dockerfile for
the arm/amd64 architecture using Docker’s docker build
command. Subsequently, the built image is pushed to the DockerHub
repository using Docker’s docker push command.
In this job, it tests the running Docker image by proxying a
curl command to google.fr via the squid proxy running
inside the container.
Dive is a tool for exploring a Docker image, layer contents, and
discovering ways to shrink the size of your Docker/OCI image. It fetches
the Docker image using docker pull and then explores that
image using dive.
This script tags the Docker image with the Squid version number and pushes it to Docker Hub. A separate tag ‘latest’ is also pushed to Docker Hub.
Generates a markdown and HTML report of the pipeline’s functioning using OpenAI’s ChatGPT.
Updates the README.md of the Docker Hub repo with the README.md file from the GitLab repo.
Environment variables and files are heavily used to store, convey and share information across the jobs in the pipeline:
GIT_CLONE_PATH: The path where the repo should be
cloned during the pipeline execution.CONTAINER_CLIENT_IMAGE: Docker image used to run
commands inside the GitLab CI/CD environmentvariables.env: This file is used to store the version
number of Squid fetched in getsquid_vars job. This file is
picked up in subsequent jobs to fetch version number.DOCKER_HUB_USER and DOCKER_HUB_TOKEN:
These are presumably saved in GitLab’s CI/CD settings and used to
authenticate with Docker Hub for pushing Docker images.HUB_REGISTRY_IMAGE: The Docker image’s name under
docker hub repository.GITLAB_TOKEN: Used to push changes to GitLab
repository.Jobs in GitLab CI/CD pipeline often depend on other jobs. Jobs in one
stage can depend on the jobs from stages above it. In this pipeline,
nearly all significant jobs are dependent on getsquid_vars
job, as it provides the version of Squid software.
Also, docker-hub-build/test jobs for both arm and amd64 are dependent on each other to ensure that Docker image build and tests are successful on both architectures.
Test and push jobs also depend on their corresponding docker build job to ensure we only push a verified worker image.
Chatgpt_analysis and
update_dockerhub_readme jobs are dependent on
getsquid_vars, docker-hub-test and
docker-hub-test-arm to ensure they run after Docker images
have been built and tested on both architectures.
getsquid_vars: Generates a variables.env
file containing the version of Squid software, used by many other
jobs.docker-hub-build-arm/docker-hub-build: Docker image
built and pushed to DockerHub.docker-hub-test-arm/docker-hub-test: If the job ends
successfully, that means the Docker image works fine.dive-arm/dive: Insights on how to reduce the Docker
image size.push-docker-hub-arm/push-docker-hub: Successful
completion of this job signifies that the Docker image has been
deployed.chatgpt_analysis: Generates
chatgpt_analysis_date.md file and HTML report.update_dockerhub_readme: README on DockerHub
updated.The latest commit, with commit hash 9dc6e16, has the
purpose of automatically updating the project README. Its impact on the
pipeline is minimal; it does not influence the building, testing, or
deploying the Docker image, but it ensures that the README.md in the
repository is always kept up-to-date with the latest Squid version.