GitOps est une combinaison de bonnes pratiques pour automatiser le déploiement de conteneurs et d'infrastructures. Au lieu de manipuler des changements de configuration en les poussant activement, ici les systèmes synchronisent leurs états automatiquement par rapport à un référentiel contrôlé. À travers de ce workshop, vous découvrirez comment mettre en œuvre cette méthode pour gérer automatiquement des clusters Kubernetes avec l'outil Flux qui vient récemment de sortir en version 2.

1. 10 novembre 2021
Flux 2 GitOps-based
Kubernetes management
Katia HIMEUR TALHI et Charles-Edouard GAGNAIRE

2. Who are we?
Katia, Tech Lead DevOps
➔ Katia HIMEUR TALHI
➔ @katia_tal
➔ https://dev.to/katiatalhi

3. Who are we?
Charles-Edouard, Tech Lead AWS
➔ Charles-Edouard Gagnaire
➔ @baalooos
➔ https://dev.to/baalooos

4. 1 - 2 What is Gitops ?
3 - 4 Push vs Pull
5 - 9 Flux
10 - Demo
Sommaire

5. What is GitOps ?
01
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6. Gérez vos clusters Kubernetes avec Flux 2 et la méthode GitOps– V°001| 10 novembre 2021
What is GitOps ?
● Way of implementing Continuous Deployment for cloud native
applications
● The desired state of the infrastructure is described in a declarative way
in Git repository
● An automated process makes the environment match the described
state in the repository.
● Git repository as the central element of GitOps
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7. Benefits of GitOps
02

8. Benefits of
GitOps
● History of how the environment
changed over time
● Roll back
● Complete description of what is
deployed
● Git Repository is the central
element

9. Benefits of
GitOps
● Reduce the number of tools used :
Git Repository is the central
element
● History of how the environment
changed over time
● Roll back
● Manage deployments from inside
your environment
● Complete description of what is
deployed

10. Push/Pull deployment strategy
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11. Push deployment strategy
03

12. Push Strategy
➔ A third party pushes new ressources to the
cluster
➔ You need credentials to access the cluster
➔ It’s hard to check for drifts in the cluster

13. Pull Strategy
➔ An operator in the cluster checks the Git
repository at a regular interval
➔ Automated
➔ Overwrites manual changes
➔ Works with container registries

14. How it works ?
➔ Updating application trigger a build
pipeline
➔ A container image is build
➔ The environment configuration repository is
updated
➔ Deployment pipeline is triggered

15. Keep in mind
➔ The CI/CD deployment tools have to know
the necessary credentials to deploy.
➔ Drifts between the state of the environment
and the desired state can not be noticed
automatically

16. Pull deployment strategy
04
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17. How it works
➔ An operator continuously comparing the
desired state of the infrastructure with the
actual state
➔ If differences are noticed, the operator
updates the infrastructure to match the
desired state described in the Git repository
➔ A container registry can be monitored to
find new versions of images to deploy

18. Flux
04

19. Flux
➔ https://github.com/fluxcd/flux
➔ Go
➔ Kubernetes
➔ Runs inside your cluster

20. Sources
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21. Source types
● Sources can be :
○ GitRepository
○ HelmRepository
○ ...

22. Source types
● Sources can be :
○ GitRepository
○ HelmRepository
○ Bucket resources.

23. Gérez vos clusters Kubernetes avec Flux 2 et la méthode GitOps– V°001| 10 novembre 2021
Sources
● May be shared by multiple consumers
● Checked for changes on a defined interval
● Specified as Custom Resources in a Kubernetes cluster
● Sources are an artifact consumed by other Flux components
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24. Gérez vos clusters Kubernetes avec Flux 2 et la méthode GitOps– V°001| 10 novembre 2021
Sources
● Origin of repository containing the desired state and requirements
● May be shared by multiple consumers
● Checked for changes on a defined interval
● Specified as Custom Resources in a Kubernetes cluster
● Sources produce an artifact that is consumed by other Flux
components to perform actions
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25. Reconciliation
06

26. Reconciliation
➔ Mechanism of keeping the system matches
the desired state.
➔ Reconciliation runs by default every minute
➔ The reconciliation interval can be
customized

27. Kustomization
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28. Gérez vos clusters Kubernetes avec Flux 2 et la méthode GitOps– V°001| 10 novembre 2021
Kustomization
● Custom resource
● Local set of Kubernetes resources that Flux reconcile
● Two kustomization types :
○ kustomization.kustomize.toolkit.fluxcd.io
○ kustomization.kustomize.config.k8s.io
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29. Gérez vos clusters Kubernetes avec Flux 2 et la méthode GitOps– V°001| 10 novembre 2021
kustomization.kustomize.toolkit.fluxcd.io
● Kubernetes custom resource
● refers to a kustomization.yaml file path inside a Git
repository or Bucket source.
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30. Gérez vos clusters Kubernetes avec Flux 2 et la méthode GitOps– V°001| 10 novembre 2021
kustomization.kustomize.config.k8s.io
● Used to configure kustomize overlay
● Tool used to customize Kubernetes objects in a
template-free way. It provides several features that
allow us to customize the application’s configuration.
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31. Bootstrap
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32. Bootstrap
● Process of installing Flux
components
● Everything happens in the version
control used for the application
● Two ways to do bootstrap :
○ using Flux CLI
○ using Terraform provider

33. Bootstrap
● Process of installing Flux
components
● Everything happens in the version
control used for the application
● Two ways to do bootstrap :
○ using Flux CLI
○ using Terraform provider
● The bootstrap is idempotent

34. Demo !

35. thank you !