DEVOPS Assignment

You are required to set up a GitLab server, create a CI/CD pipeline to build and push a Docker image, and set up monitoring. Steps:

1. Set up a GitLab Server:
   • Install and configure a GitLab server on your local machine or use GitLab.com.
2. Create a New Project in GitLab:
   • Create a new project repository in GitLab.
3. Clone the Repository:
   • Clone the repository https://github.com/docker/docker-gs-ping into your GitLab project.
4. Set up a GitLab Runner:
   • Install and configure a GitLab Runner that can execute CI jobs for your project.
5. CI/CD Pipeline - Write a CI job which:
   • Builds the container image from the Dockerfile.multistage.
   • Pushes the built image to the GitLab container registry.
6. Monitoring:
   • Set up monitoring using Prometheus and Grafana to visualize the health and performance of the application.
   • Create dashboards to monitor key metrics such as CPU usage, memory usage, and request rates.
7. Documentation - Provide a README file with:
   • Instructions on how to set up the GitLab server and runner.
   • Steps to clone the repository and configure the CI/CD pipeline.
   • Details on how to access and interpret the monitoring dashboards.
   • Any assumptions, limitations, and potential improvements.

Solution

The gitlab url will be gitlab. For simplicity, place this line in your hosts file

127.0.0.1   gitlab
127.0.0.1   prometheus
127.0.0.1   grafana

• Configure the Docker daemon to serve metrics https://docs.docker.com/engine/daemon/prometheus/

Setup of the Gitlab Server and Runner

• docker-compose file contents
  • Mailpit https://hub.docker.com/r/axllent/mailpit
  • Gitlab https://docs.gitlab.com/install/docker/installation/#install-gitlab-by-using-docker-compose
  • Runner https://docs.gitlab.com/runner/install/docker/
  • register-runner job

Copy the .env file.

cp .env.example .env

Launch the stack

docker compose up -d

Receive the root password from Gitlab container

docker exec -it gitlab grep 'Password:' /etc/gitlab/initial_root_password

Configure Gitlab

• login with root user
• To import ping repo from Github
  • Admin -> Settings -> Import and export settings -> Import sources -> Github
• Configure Runner
  • CI/CD -> Runners -> Create instance runner
  • copy token and paste to .env
  • register runner

  docker compose run --rm register-runner

  • grant gitlab-runner jobs access to docker daemon
    • Edit data/gitlab-runner/config/config.toml
    • Add line to [runners.docker]

Create Project

• Plus -> Create new project
• Clone the GitHub repo

git clone https://github.com/docker/docker-gs-ping

• Add your GitLab repo as a new remote to the cloned local repo:

git remote set-url origin https://gitlab/root/docker-gs-ping.git

• Rebase main on remote main and push

git pull origin main --rebase
git push -u origin main

• Don't verify SSL certificates for this exercise

git config http.sslVerify "false"

Adapt Ping App

• Added pipeline config

# .gitlab-ci.yml

• Added metrics endpoint

Build and launch

• In Gitlab project trigger the pipeline
• Login to Gitlab container registry

docker login gitlab:5050 

• Launch the app

docker compose --profile app up -d 

Monitoring in Grafana

• Access Dashboard on http://grafana:3000/
  • Login with admin/admin

Any assumptions, limitations, and potential improvements.

Improvements

• Run in K8s cluster
• Deploy app from pipeline
• Ingress controller
• Alerts, Incident detection
• Log shipping
• request tracing
• Check against company standards and policies
• retention policies for timeseries data, docker images, logs
• backup and restore process
• target hardware managed by infrastructure as code
• deploy with GitOps approach
• Pipeline branch management
• Continuous Deployment
• Issue valid certificates
• Security!
  • Firewall rules on hosts
  • secure store for authentication credentials
• SSO for all services
• decentralized data storage
• Continuous profiling