GitLab Pipeline Explanation

“Squid squid-6.13 ChatGPT Analysis”

Here is an explanation of each stage in the pipeline and how each job plays a part.

Job List with Brief Description

Following the order of stages in the .gitlab-ci.yml file, the jobs are:

1. hadolint

• Stage: Quality
• Description: This job uses the hadolint/hadolint image to lint the Dockerfile.

2. getsquid_vars

• Stage: Get-Version
• Description: This job fetches the latest version of squid from GitHub and generates an environment file (variables.env), which is used in subsequent jobs. The README is also updated with the fetched version.

3. docker-hub-build and docker-hub-build-arm

• Stage: Docker-hub-build
• Description: These jobs build the Docker images for x86 and ARM, respectively.

4. docker-hub-test and docker-hub-test-arm

• Stage: Docker-hub-test
• Description: These jobs test the Docker images built in the docker-hub-build and docker-hub-build-arm jobs.

5. push-docker-hub and push-docker-hub-arm

• Stage: Docker-hub-pushtag
• Description: These jobs tag and push Docker images to Docker Hub repository.

6. chatgpt_analysis

• Stage: Docs
• Description: This job facilitates the communication with the OpenAI API, performing a detailed analysis of the pipeline features and operations.

7. update_dockerhub_readme

• Stage: Docs
• Description: Updates the README file in Docker Hub with the current README file from the Git repository.

Each of these jobs serves a key role in the CI/CD process. CI (Continuous Integration) activities include code linting and Docker image building and testing, while CD (Continuous Deployment) involves pushing Docker images to Docker Hub.

Purpose of each Job

hadolint job

This job is used to lint Dockerfiles for best practices and common mistakes.

hadolint:
 image: hadolint/hadolint:latest-debian
 stage: Quality
 before_script:
 - cd $CI_PROJECT_DIR 
 script:
 - hadolint --ignore DL3008 Dockerfile

• hadolint is a popular command-line tool for linting Dockerfile.
• image: hadolint/hadolint:latest-debian specifies the Docker image used for this job, which is a Hadolint image.
• before_script: changes the current working directory to the project’s root directory.
• hadolint --ignore DL3008 Dockerfile runs Hadolint on the Dockerfile ignoring rule DL3008.

It uses hadolint/hadolint:latest-debian Docker image to run the hadolint command to lint Dockerfile, ignores the rule DL3008 regarding the version pinning in apt-get install.

getsquid_vars job

This job retrieves the latest version of Squid from its GitHub repository, prepares an environment file with the version, and updates the README.md file.

getsquid_vars:
 stage: Get-version
 image: 
 name: $CONTAINER_CLIENT_IMAGE
 artifacts:
 expire_in: 1 hour
 paths:
 - variables.env
 script:
 - apt update && apt install git curl ca-certificates -y --no-upgrade --no-install-recommends --no-install-suggests
 - export SQUID_VERSION=$(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 || true

• apt update && apt install git curl ca-certificates -y --no-upgrade --no-install-recommends --no-install-suggests updates the packages list and installs required packages.
• curl -LsXGET https://github.com/squid-cache/squid/releases/latest | grep -m 1 "Release" | cut -d " " -f4 |tr -d 'v' retrieves the latest Squid version from the official GitHub repository.
• SQUID_VERSION is set to the retrieved Squid version and saved in the variables.env file.
• sed commands replace placeholders in the README_template.md with the Squid version and the current date.
• git config, git add, git commit and git push commands update and commit the new README file to the repository.

docker-hub-build and docker-hub-build-arm jobs

docker-hub-build and docker-hub-build-arm jobs build Docker images specific to x86 and ARM architectures using the latest Squid version. Docker images are then pushed to Docker Hub.

docker-hub-build:
 stage: Docker-hub-build
 image: docker:dind
 needs: 
 - getsquid_vars
 artifacts:
 expire_in: 2 hours
 paths:
 - $CI_PROJECT_DIR 
 timeout: 3 hours 
 before_script:
 - docker login -u "$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_AMD64

• docker:dind is the Docker in Docker image that allows running Docker commands within the GitLab CI environment.
• This job requires getsquid_vars to have been executed first since it relies on the variables.env file that the getsquid_vars job produces.
• docker login -u "$DOCKER_HUB_USER" -p "$DOCKER_HUB_TOKEN" $DOCKER_HUB_REGISTRY logs into Docker Hub.
• Docker images are built using docker build, with the Squid version passed as a build argument, and tagged with the name stored in CONTAINER_BUILD_NOPROD_NAME_AMD64 or CONTAINER_BUILD_NOPROD_NAME_ARM.
• The newly created images are pushed to Docker Hub with docker push.

docker-hub-test and docker-hub-test-arm jobs

The docker-hub-test and docker-hub-test-arm jobs test the Docker images for x86 and ARM that were built in the previous stage.

docker-hub-test:
 stage: Docker-hub-test
 extends: .services-amd64
 before_script:
 - apt update && apt install -y curl --no-upgrade --no-install-recommends --no-install-suggests
 script:
 - export https_proxy=http://$CONTAINER_TEST_NAME:3128 && curl -k https://www.google.fr
 variables:
 HOSTNAME: squidpipeline
 needs: ["docker-hub-build"]

• Assume the services specified in .services-amd64.
• apt update && apt install -y curl --no-upgrade --no-install-recommends --no-install-suggests updates the packages list and installs curl.
• export https_proxy=http://$CONTAINER_TEST_NAME:3128 && curl -k https://www.google.fr sets an HTTP proxy to the Docker container’s Squid instance and tries to curl an HTTPS website.
• This job depends on the docker-hub-build job.

push-docker-hub and push-docker-hub-arm jobs

The push-docker-hub and push-docker-hub-arm jobs tag and push Docker images to Docker Hub repository.

push-docker-hub:
 stage: Docker-hub-pushtag
 image: docker:dind
 needs: 
 - docker-hub-test
 - getsquid_vars
 before_script:
 - docker login -u "$DOCKER_HUB_USER" -p "$DOCKER_HUB_TOKEN" $DOCKER_HUB_REGISTRY
 script:
 - source variables.env
 - docker pull $CONTAINER_BUILD_NOPROD_NAME_AMD64
 - docker tag $CONTAINER_BUILD_NOPROD_NAME_AMD64 $HUB_REGISTRY_IMAGE:$SQUID_VERSION-amd64 
 - docker push $HUB_REGISTRY_IMAGE:$SQUID_VERSION-amd64
 - docker tag $CONTAINER_BUILD_NOPROD_NAME_AMD64 $HUB_REGISTRY_IMAGE:latest-amd64
 - docker push $HUB_REGISTRY_IMAGE:latest-amd64
 - docker tag $CONTAINER_BUILD_NOPROD_NAME_AMD64 $HUB_REGISTRY_IMAGE:latest
 - docker push $HUB_REGISTRY_IMAGE:latest
 variables:
 GIT_STRATEGY: none
 only:
 - master

• Logs into Docker Hub, pull the image, tag it, and push it to Docker Hub.
• This job depends on the docker-hub-test and getsquid_vars jobs.
• Docker images are tagged with the version fetched from the getsquid_vars job and latest, then pushed to Docker Hub.
• The GIT_STRATEGY: none variable is used here to save bandwidth as there’s no need to clone the Git repository.

chatgpt_analysis job

This job performs a detailed analysis of the pipeline features and operations using the GPT-4 model of OpenAI.

chatgpt_analysis:
 stage: Docs
 image: 
 name: $CONTAINER_CLIENT_IMAGE
 artifacts:
 expire_in: 1 month
 paths:
 - $CI_PROJECT_DIR/chatgpt_analysis*
 needs: 
 - getsquid_vars
 - docker-hub-test
 - docker-hub-test-arm
 before_script:
 - apt update && apt install curl git jq ca-certificates pandoc openssh-client -y --no-upgrade --no-install-recommends --no-install-suggests
 - source variables.env
 - SQUID_VERSION=squid-$SQUID_VERSION
 script: 
 - JOBS_CONTENT=$(cat .gitlab-ci.yml gitlabci/*)
 - LAST_COMMIT=$(git log -1 --pretty=format:"%h %s%n%b")
 - JSON_CONTENT=$(jq -n --arg model "gpt-4" --arg content "$CONTENT" '{model:$model, messages:[{role:"user", content:$content}] }')
 - RESPONSE=$(curl -X POST https://api.openai.com/v1/chat/completions -H "Authorization:Bearer $CHATGPT_API_KEY" -H "Content-Type:application/json" -d "$JSON_CONTENT")
 - echo "!!! See Artifact for explanations or https://e2guardian.numsys.eu !!!"
 only:
 - master

• It communicates with the OpenAI API, creates a JSON request message where the content section is filled with a detailed manual about the components and operations involved in the pipeline.
• Sends the JSON request to the OpenAI API using curl.
• The response from the OpenAI API is stored within markdown files that are set as the job’s artifacts.
• The updated markdown file is transferred to a remote server using scp.

update_dockerhub_readme job

The update_dockerhub_readme job updates the README file in Docker Hub with the current README file from the Git repository.

update_dockerhub_readme:
 image: 
 name: $CONTAINER_CLIENT_IMAGE
 stage: Docs
 artifacts:
 needs: 
 - getsquid_vars
 before_script:
 - apt update && apt install -y curl jq ca-certificates --no-upgrade --no-install-recommends --no-install-suggests
 script:
 - README_CONTENT=$(cat README.md) 
 - PAYLOAD=$(jq -n --arg desc "$README_CONTENT" '{"full_description":$desc}')
 - TOKEN=$(curl -v -s -X POST -H "Content-Type:application/json" -d '{"username":"'"$DOCKER_HUB_USER"'","password":"'"$DOCKER_HUB_PASSWORD"'"}' https://hub.docker.com/v2/users/login/ | jq -r .token)
 - curl -X PATCH -H "Authorization:JWT $TOKEN" -H "Content-Type:application/json" -d "$PAYLOAD" https://hub.docker.com/v2/repositories/$HUB_REGISTRY_IMAGE
 only:
 - master

• Sends an API request to Docker Hub to update the description (README content) of the repository’s Docker Hub page.
• This job depends on the getsquid_vars job as the README file is updated with the Squid version during this job.

Parameters, Environment Variables, and File References

Several parameters and environment variables are used throughout the pipeline:

• $CI_PROJECT_DIR: An environment variable automatically provided by GitLab that represents the absolute path to the directory of the project.
• $CI_BUILDS_DIR: Path to the directory designated for build artifacts.
• CONTAINER_CLIENT_IMAGE, CONTAINER_BUILD_NOPROD_NAME_ARM, CONTAINER_BUILD_NOPROD_NAME_AMD64, CONTAINER_TEST_NAME: These are different Docker containers and Docker images involved in the pipeline.
• HOSTNAME, GIT_STRATEGY: Various configurations for the pipeline.
• $SQUID_VERSION: The latest version of Squid.
• $DOCKER_HUB_USER, $DOCKER_HUB_PASSWORD, $DOCKER_HUB_TOKEN: Credentials for Docker Hub.
• $DOCKER_HUB_REGISTRY: Docker Hub registry.
• $CI_COMMIT_BRANCH, $CI_COMMIT_TITLE, $CI_PIPELINE_URL, $CI_PROJECT_URL: Provided by GitLab, these represent different metadata about the Git commit and the GitLab project.
• variables.env: An output file used for passing variables between stages.

The variables defined in the variables: keyword at the top of the .gitlab-ci.yml file are global and can be used in all jobs. In addition, each job can define its own variables in the variables: keyword inside a job.

Dependencies between Jobs or Stages

• docker-hub-build, docker-hub-build-arm jobs need the getsquid_vars job.
• docker-hub-test, docker-hub-test-arm jobs need the docker-hub-build, docker-hub-build-arm jobs respectively.
• push-docker-hub, push-docker-hub-arm jobs need the docker-hub-test, docker-hub-test-arm, getsquid_vars jobs respectively.
• chatgpt_analysis job needs the getsquid_vars, docker-hub-test, docker-hub-test-arm jobs.
• update_dockerhub_readme job needs getsquid_vars job.

These dependencies are specified using the needs: keyword. The dependencies mean the job needs the artifacts or the outcome of the previous job to be able to work correctly.

Expected Outcomes or Artifacts

Each job can produce artifacts that are used or passed to subsequent jobs in the pipeline.

For example, getsquid_vars job produces variables.env as an artifact that is used by subsequent jobs to fetch the latest Squid version.

Those artifacts are automatically uploaded, by the runner, to GitLab’s built-in artifact storage, so they can easily be downloaded by the other jobs, or from the GitLab Web UI.

Artifacts are defined under artifacts: where paths: specifies the file or directory to be attached as an artifact and expire_in: specifies the duration artifacts should be kept before they are deleted.

Last Commit

The last commit has the message “README Auto update [skip ci]” with the commit hash b7aab88. This commit is made in the getsquid_vars job, which updates the README with the latest version of Squid fetched from GitHub and then commits the change in README. The “[skip ci]” in the commit message instructs the CI/CD pipeline to skip running jobs for this commit.

Project:https://gitlab.com/fredbcode-images/squid Pipeline:https://gitlab.com/fredbcode-images/squid/-/pipelines/1745727640 Docker images:https://hub.docker.com/r/fredbcode