View source for Kubernetes/Progressive Delivery Flux and Flagger

= [https://github.com/fluxcd/flux2 Flux v2] =
Flux v2 architecture
:[[File:ClipCapIt-210524-232835.PNG]]

Flux v2 - Webhooks and notifications
:[[File:ClipCapIt-210524-233028.PNG]]


Docs:
* [https://fluxcd.io/docs/ Flux v2 Documentation]

= Install Flux v2 [https://fluxcd.io/docs/cmd/ <code>flux</code>] command line =
* [https://fluxcd.io/docs/get-started/ Fluxv2 Get Started]


{{Note|<code>fluxctl</code> is a previous version Flux v1 command line tool.}}
<source lang=bash>
# Install or upgrade using official install.sh (option-1)
export FLUX_VERSION=0.37.0; curl -s https://fluxcd.io/install.sh | sudo -E bash
curl -s https://fluxcd.io/install.sh | sudo bash # latest

# Install from GitHub releases (option-2)
REPO=fluxcd/flux2
LATEST=$(curl --silent "https://api.github.com/repos/$REPO/releases/latest" | jq -r .tag_name | tr -d v); echo $LATEST
VERSION=$LATEST
TEMPDIR=$(mktemp -d); FILE=flux_${VERSION}_linux_amd64
curl -L https://github.com/$REPO/releases/download/v${VERSION}/$FILE.tar.gz -o $TEMPDIR/$FILE.tar.gz
tar xzvf $TEMPDIR/$FILE.tar.gz -C $TEMPDIR
sudo install $TEMPDIR/flux /usr/local/bin/flux
sudo install $TEMPDIR/flux /usr/local/bin/flux_${VERSION}

# enable completions in ~/.bash_profile
. <(flux completion bash)

# TODO: Via release binaries
# https://github.com/fluxcd/flux/releases

# Pre check
flux check --pre
► checking prerequisites
✗ flux 0.25.1 <0.25.2 (new version is available, please upgrade)
✔ Kubernetes 1.21.5-gke.1302 >=1.19.0-0
✔ prerequisites checks passed

# Docker images
docker pull fluxcd/fluxctl:1.24.3
docker pull ghcr.io/fluxcd/flux-cli:1.24.3 # does not work
</source>

= Cluster bootstrap =
FluxCDv2 bootstrap process is installing the Flux onto a cluster and stores(commits) its own manifests to a Git repository.
* [https://fluxcd.io/docs/installation/#generic-git-server Generic Git Server], including GCP [https://cloud.google.com/source-repositories/docs Cloud Source Repositories]
* [https://fluxcd.io/docs/installation/#bootstrap-with-terraform Bootstrap with Terraform]


<source lang=bash>
FLUX_GIT_USERNAME=my-git-username
FLUX_GIT_EMAIL=my-git-email@example.com
flux bootstrap git \
  --author-email=$FLUX_GIT_EMAIL \
  --url=ssh://git@github.com/$FLUX_GIT_USERNAME/gitops-istio \
  --branch=main \
  --path=clusters/my-cluster
</source>
At bootstrap, Flux generates an SSH key and prints the public key. In order to sync your cluster state with git you need to copy the public key and create a deploy key with write access on your GitHub repository. On GitHub go to Settings > Deploy keys click on Add deploy key, check Allow write access, paste the Flux public key and click Add key.


;[https://fluxcd.io/docs/installation/#dev-install Dev installation] does not stores its own configuration state in Git repository
<source lang=bash>
# option 1
flux install # install and upgrade
flux install \
--namespace=flux-system \
--network-policy=false \
--components=source-controller

# option 2
kubectl apply -f https://github.com/fluxcd/flux2/releases/latest/download/install.yaml
kustomize build https://github.com/fluxcd/flux2/manifests/install?ref=main | kubectl apply -f- # Upgrade

# Register Git repositories and reconcile them on your cluster:
flux create source git podinfo \
  --url=https://github.com/stefanprodan/podinfo \
  --tag-semver=">=4.0.0" \
  --interval=1m

flux create kustomization podinfo-default \
  --source=podinfo \
  --path="./kustomize" \
  --prune=true \
  --validation=client \
  --interval=10m \
  --health-check="Deployment/podinfo.default" \
  --health-check-timeout=2m

# Register Helm repositories and create Helm releases:
flux create source helm bitnami \
  --interval=1h \
  --url=https://charts.bitnami.com/bitnami

flux create helmrelease nginx \
  --interval=1h \
  --release-name=nginx-ingress-controller \
  --target-namespace=kube-system \
  --source=HelmRepository/bitnami \
  --chart=nginx-ingress-controller \
  --chart-version="5.x.x"
</source>


Uninstall
<source lang=bash>
flux uninstall --namespace=flux-system
</source>

= References =
* [https://github.com/fluxcd/terraform-provider-flux terraform-provider-flux]
*[https://github.com/pio2pio/gitops-istio gitops-istio] Tutorial
*[https://www.youtube.com/watch?v=nGLpUCPX8JE Flux v2 Everything that you wanted to know but were afraid to ask (Stefan Prodan)] December 2020


Bundle
*[https://blog.sldk.de/2021/02/introduction-to-gitops-on-kubernetes-with-flux-v2/ Introduction to GitOps on Kubernetes with Flux v2]
*[https://blog.sldk.de/2021/03/handling-secrets-in-flux-v2-repositories-with-sops/ Handling secrets in Flux v2 repositories with SOPS]