# 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](https://kind.sigs.k8s.io/) </br>

```
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. </br>
We can get this utility from the GitHub [Releases page](https://github.com/fluxcd/flux2/releases) </br>

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](https://fluxcd.io/flux/installation/#prerequisites) page. </br>

```
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 </br>
The [Core Concepts](https://fluxcd.io/flux/concepts/) is a good place to start. </br>

We begin by following the steps under the [bootstrap](https://fluxcd.io/flux/installation/#bootstrap) section for GitHub </br>

We'll need to generate a [personal access token (PAT)](https://github.com/settings/tokens/new) that can create repositories by checking all permissions under `repo`.  </br>

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 
```