docker-development-youtube-series/kubernetes/fluxcd

Introduction to Flux CD v2

Create a kubernetes cluster

In this guide we we''ll need a Kubernetes cluster for testing. Let's create one using kind

kind create cluster --name fluxcd --image kindest/node:v1.23.5

See cluster up and running:

kubectl get nodes
NAME                  STATUS   ROLES                  AGE     VERSION
fluxcd-control-plane   Ready    control-plane,master   2m12s   v1.23.5

Run a container to work in

run Alpine Linux:

docker run -it --rm -v ${HOME}:/root/ -v ${PWD}:/work -w /work --net host alpine sh

install some tools

# install curl 
apk add --no-cache curl

# install kubectl 
curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl
chmod +x ./kubectl
mv ./kubectl /usr/local/bin/kubectl

# install helm 

curl -o /tmp/helm.tar.gz -LO https://get.helm.sh/helm-v3.10.1-linux-amd64.tar.gz
tar -C /tmp/ -zxvf /tmp/helm.tar.gz
mv /tmp/linux-amd64/helm /usr/local/bin/helm
chmod +x /usr/local/bin/helm

test cluster access:

/work # kubectl get nodes
NAME                    STATUS   ROLES    AGE   VERSION
fluxcd-control-plane   Ready    control-plane,master   3m26s   v1.23.5

Flux CD

get flux command-line tool

Let's download the flux command-line utility.
We can get this utility from the GitHub Releases page

It's also worth noting that you want to ensure you get a compatible version of flux which supports your version of Kubernetes. Checkout the prerequisites page.

curl -o /tmp/flux.tar.gz -sLO https://github.com/fluxcd/flux2/releases/download/v0.41.1/flux_0.41.1_linux_amd64.tar.gz
tar -C /tmp/ -zxvf /tmp/flux.tar.gz
mv /tmp/flux /usr/local/bin/flux
chmod +x /usr/local/bin/flux

Now we can run flux --help to see its installed

Check our cluster

flux check --pre

Documentation

As with every guide, we start with the documentation
The Core Concepts is a good place to start.

We begin by following the steps under the bootstrap section for GitHub

We'll need to generate a personal access token (PAT) that can create repositories by checking all permissions under repo.

Once we have a token, we can set it:

export GITHUB_TOKEN=<your-token>

Then we can bootstrap it using the GitHub bootstrap method

flux bootstrap github \
  --owner=marcel-dempers \
  --repository=docker-development-youtube-series \
  --path=kubernetes/fluxcd/clusters/dev-cluster \
  --personal \
  --branch fluxcd-2022

flux check

# flux manages itself using GitOps objects:
kubectl -n flux-system get GitRepository
kubectl -n flux-system get Kustomization

Check the source code that flux bootstrap created

git pull origin <branch-name>

Repository structure

https://fluxcd.io/flux/guides/repository-structure/

• Mono Repo
• Repo per team
• Repo per app

- apps
  - example-app-1
  - example-app-2
- infrastructure
  - ingress-nginx
  - monitoring
- clusters
  -dev-cluster
  -prod-cluster

build our app

cd kubernetes\fluxcd\apps\example-app-1\src

docker build . -t example-app-1:0.0.1

#load the image to our test cluster so we dont need to push to a registry
kind load docker-image example-app-1:0.0.1 --name fluxcd 

deploy our app

kubectl -n default apply -f kubernetes/fluxcd/repositories/config/apps/example-app-1/

# check our flux resources 
kubectl -n default describe gitrepository example-app-1
kubectl -n default describe kustomization example-app-1

# check deployed resources
kubectl get all