Kubernetes/Progressive Delivery Flux and Flagger

Flux v2

Flux v2 architecture

Flux v2 - Webhooks and notifications

Docs:

• Flux v2 Documentation

Install Flux v2 flux command line

• Fluxv2 Get Started

Note: fluxctl is a previous version Flux v1 command line tool.

# 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

Cluster bootstrap

FluxCDv2 bootstrap process is installing the Flux onto a cluster and stores(commits) its own manifests to a Git repository.

• Generic Git Server, including GCP Cloud Source Repositories
• Bootstrap with Terraform

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

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.

Dev installation does not stores its own configuration state in Git repository

# 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"

Uninstall

flux uninstall --namespace=flux-system

References

• terraform-provider-flux
• gitops-istio Tutorial
• Flux v2 Everything that you wanted to know but were afraid to ask (Stefan Prodan) December 2020

Bundle

• Introduction to GitOps on Kubernetes with Flux v2
• Handling secrets in Flux v2 repositories with SOPS