This document provides an introduction to Gitlab CI and continuous integration/continuous delivery (CI/CD) workflows. It discusses DevOps practices and the benefits of Gitlab CI. It then covers how to set up Gitlab runners, write a basic Gitlab CI configuration file, define jobs, stages, variables and environments. The document demonstrates concepts like Docker integration, artifacts, auto and manual deployments, and stopping deployments. It concludes with a live demo of a Gitlab CI configuration.

1. Ondrej Sika
ondrej@sika.io
@ondrejsika
Gitlab CI
Introduction

2. Agenda
- DevOps
- What is CI/CD
- Setup Gitlab CI
- Configure CI Pipeline
- Live Demo

3. DevOps
DevOps is a set of software
development practices that combine
software development (Dev) and
information-technology operations
(Ops) to shorten the
systems-development life cycle
while delivering features, fixes, and
updates frequently in close
alignment with business objectives.

4. DevOps Lifecycle

5. CI
Continuous Integration
Continuous Integration works to
integrate code from your team in a
shared repository. Developers share
their new code in a Merge (Pull)
Request, which triggers a pipeline to
build, test, and validate the new code
before merging the changes in your
repository.

6. CD
Continuous Deployment
Continuous Delivery delivers CI
validated code to your application.
Together, CI and CD accelerate how
quickly your team can deliver results
for your customers and
stakeholders. CI helps you catch and
reduce bugs early in the
development cycle, and CD moves
verified to your applications faster.

7. CI/CD Pipeline

8. Gitlab CI

9. Why Gitlab CI
- Integrated: GitLab CI/CD is part of GitLab
- Open source: CI/CD is a part of both the open source GitLab
- Seamless: Part of the single GitLab application
- Scalable: Tests run distributed on separate machines
- Faster results: Each build can be split in multiple jobs that run in parallel on
multiple machines
- Optimized for delivery: multiple stages, manual deploy gates, environments,
and variables
- Easy to learn

10. Gitlab CI Architecture

11. Gitlab Runner
- To perform the actual build, you need to install GitLab Runner which is
written in Go.
- It can run on any platform for which you can build Go binaries, including
Linux, OSX, Windows, FreeBSD and Docker.
- It can test any programming language including .Net, Java, Python, C, PHP
and others.
- GitLab Runner has many features, including autoscaling, great Docker
support, and the ability to run multiple jobs concurrently.

12. Setup Gitlab CI

13. Setup Gitlab Runners
See my setup scripts https://github.com/ondrejsika/gitlab-ci-runner
# create runner
docker run -d
--name gitlab-runner
--restart always
-v /var/run/docker.sock:/var/run/docker.sock
-v /builds:/builds
gitlab/gitlab-runner:latest

14. Get Runner Registration Token
Go to Admin -> Runners

15. Setup Gitlab Runners
# register runner to Gitlab
docker exec gitlab-runner gitlab-runner register
--non-interactive
--url $GITLABCI_URL
--registration-token $GITLABCI_TOKEN
--name $RUNNER_NAME
--executor docker
--docker-image docker:git
--docker-volumes '/var/run/docker.sock:/var/run/docker.sock'
--docker-volumes '/builds:/builds'

16. We are ready to use CI

17. How to use Gitlab CI
- Gitlab CI configuration is stored inside of the repository in file .gitlab-ci.yml
- If repository contains .gitlab-ci.yml, CI run automatically
- You can work on code & CI together and merge them together
- Smallest unit you can run is job, you can group jobs to stages (jobs run in
parallel in stage, stages run in defined order) and stages create pipeline
- You can build binaries, Docker images, deploy to Kubernetes, track
environments and much more.

18. First Gitlab CI Job
# .gitlab-ci.yml
job:
script: echo Hello World from Gitlab CI!

19. Stages
# .gitlab-ci.yml
stages:
- build
- deploy
build:
stage: build
script: docker-compose build && docker-compose push
deploy:
stage: deploy
script: helm template --set TAG=$CI_COMMIT_SHA helm/hello-world | kubectl apply -f

20. Variables
- Secret variables are defined in
Gitlab
- Some variables set CI runtime
- Public variables are defined in
.gitlab-ci.yml

21. Variables
CI
CI_PROJECT_NAME, CI_PROJECT_PATH_SLUG
CI_COMMIT_REF_NAME, CI_COMMIT_REF_SLUG
CI_COMMIT_SHA, CI_COMMIT_TAG
CI_PIPELINE_ID, CI_JOB_ID
CI_REGISTRY, CI_REGISTRY_USER, CI_REGISTRY_PASSWORD
...
https://docs.gitlab.com/ce/ci/variables/README.html

22. Artifacts
Artifacts is a list of files and
directories which are attached to a job
after it completes successfully.

23. Artifacts
job:
script: make build
artifacts:
name: "$CI_JOB_NAME"
paths:
- binaries/
when: on_failure
https://docs.gitlab.com/ce/ci/yaml/README.html#artifacts

24. Docker
- Fully supported
- Easiest way how to create build
environment
- Easiest way how to run and
distribute your software

25. Docker Environment
image: ondrejsika/ci
job:
image: ondrejsika/ci-go
script: go build server.go

26. Docker
job:
script:
- 'docker login $CI_REGISTRY
-u $CI_REGISTRY_USER
-p $CI_REGISTRY_PASSWORD'
- docker build -t $CI_REGISTRY_IMAGE .
- docker push $CI_REGISTRY_IMAGE

27. Environments
Environment is used to define that a
job deploys to a specific environment.
If environment is specified and no
environment under that name exists, a
new one will be created automatically.

28. Environment
deploy:
script: echo 'Deploy!'
environment:
name: $CI_COMMIT_REF_SLUG
url: https://$CI_COMMIT_REF_SLUG.example.com

29. Deployments - Automatic
- Manual

30. Auto vs Manual Deployments
auto_deploy_job:
script: echo Auto Deploy!
environment:
name: deployment-$CI_PIPELINE_ID
manual_deploy_job:
when: manual
script: echo Manual Deploy!
environment:
name: deployment-$CI_PIPELINE_ID

31. Stop Deployment
deploy_job:
stage: deploy
script: echo Deploy!
environment:
name: deployment-$CI_PIPELINE_ID
on_stop: stop_deploy_job
stop_deploy_job:
stage: deploy
script: echo Stop!
when: manual
environment:
name: deployment-$CI_PIPELINE_ID
action: stop

32. Demo Time!

33. https://github.com/ondrejsika/go-server-example

34. Resources
- Moje Ukazky Gitlab CI
https://ondrej-sika.cz/repozitare/#gitlab-ci
- Moje skoleni Gitlab CI
https://ondrej-sika.cz/skoleni/gitlab-ci/
- https://docs.gitlab.com/ce/ci/
- https://docs.gitlab.com/ce/ci/yaml/
- https://docs.gitlab.com/ce/ci/quick_start/

35. Thank you & Questions
Ondrej Sika
email: ondrej@sika.io
web: https://ondrej-sika.cz
twitter: @ondrejsika
linkedin: /in/ondrejsika/
Slides: https://sika.link/cncf-sk-ci