# Automating Kubernetes with GitOps Workshop
@dictcp (https://dictcp.men)

## About the workshop

Session at HKOSCon 2020: https://hkoscon.org/2020/topics/automating-kubernetes-gitops
Video recording: https://www.youtube.com/watch?v=xykc3AsMQ04
Slide: https://docs.google.com/presentation/d/1rA6bhCGMydP-NOmFu7fv0zbBSzGvK9GLn63H8dHLP2g

## Context
- [Hands-on Preparation](#hands-on-preparation)
- [Install k3s Kubernetes on your VM](#install-k3s-kubernetes-on-your-vm)
- [Install Helm & fluxctl](#install-helm---fluxctl)
- [Prepare the git repository for GitOps](#prepare-the-git-repository-for-gitops)
- [Install fluxcd](#install-fluxcd)
- [fluxcd playaround](#fluxcd-playaround)
- [Install Helm operator](#install-helm-operator) (bonus)
- [Helm operator playaround](#helm-operator-playaround) (bonus)
- [Set up Lens](set-up-lens) (bonus)
- [Continuous Delivery](continuous-delivery) (bonus)


## Hands-on Preparation

You need 
- a GitHub account (to access this material and setup gitops flow)
- a working Kubernetes in the hands-on session (to s)
  - [multipass VM](#multipass-vm) (local installation, recommended)
  - [DigitalOcean VM](#digitalocean-vm) (remote installation)

### multipass VM

1. Install multipass on https://multipass.run
    - support Windows 10 Pro+, Mac OS X, Linux
    - Mac OS X (with homebrew installed): `brew cask install multipass`
    - Ubuntu (or any Linux distro with snap installed): `sudo snap install multipass --classic`
2. Start Command prompt / Terminal
3. Execute `multipass launch -d 30G -m 2G --name fluxcd-workshop 18.04`
4. Depends on network condition, you need to wait for 5-20 mins.
5. Check the IP of your VM via command `multipass info fluxcd-workshop`
```
Name:           fluxcd-workshop
State:          Running
IPv4:           192.168.64.15
Release:        Ubuntu 18.04.4 LTS
Image hash:     55646c02a8bc (Ubuntu 18.04 LTS)
Load:           1.46 5.28 3.97
Disk usage:     4.5G out of 28.9G
Memory usage:   1.5G out of 1.9G
```
6. Execute `multipass shell fluxcd-workshop` to obtain shell in the VMs

### DigitalOcean VM
1. (If need) Signup DigitalOcean via https://m.do.co/c/3c4b5bb5da42
2. create a droplet with 2GB and Ubuntu 18.04
    - https://cloud.digitalocean.com/droplets/new?size=s-2vcpu-2gb&region=sgp1&distro=ubuntu&distroImage=ubuntu-18-04-x64
    - You may set up Password Authentication for simpicity
3. Wait a few minutes, and you can connect to the `ssh root@<<YOUR_DROPLET_IP>>`

## Install k3s Kubernetes on your VM

1. Connect to the shell of the VM set up
2. Execute `curl -sfL https://get.k3s.io | sh -` in the VM
3. Depends on network condition, you need to wait for 5-10 mins.
4. You should have your local Kubernetes cluster installed. To verify, execute `sudo -i k3s kubectl get nodes`, it should give you something like
```
NAME              STATUS   ROLES    AGE     VERSION
fluxcd-workshop   Ready    master   5m53s   v1.18.3+k3s1`
```
5. Make sure the cluster setup is avaiable by the following commands: 
```
$ mkdir .kube
$ sudo cat /etc/rancher/k3s/k3s.yaml > .kube/config
```

## Install Helm & fluxctl
Normally you can install helm and fluxctl with the following 4 commands:
```
sudo snap install kubectl --classic
sudo snap install helm --classic --channel=3.0/stable
sudo snap install fluxctl --classic
sudo rm /usr/local/bin/kubectl
```

### Manual steps (if the above does not work)
- Helm
```
$ curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3
$ chmod 700 get_helm.sh
$ ./get_helm.sh
$ helm version
version.BuildInfo{Version:"v3.2.3", GitCommit:"8f832046e258e2cb800894579b1b3b50c2d83492", GitTreeState:"clean", GoVersion:"go1.13.12"}
```
- fluxctl
```
wget -O fluxctl https://github.com/fluxcd/flux/releases/download/1.19.0/fluxctl_linux_amd64
chmod +x fluxctl
sudo mv fluxctl /usr/local/bin/
```

## Prepare the git repository for GitOps

1. Fork https://github.com/dictcp/flux-get-started in GitHub to your own account

## Install fluxcd

1. Setup the chart repository for flux
```
helm repo add fluxcd https://charts.fluxcd.io
```

2. Install flux on Kubernetes cluster via Helm, with following commands
```shell
$ export GHUSER="dictcp"

$ kubectl create ns flux
$ helm upgrade -i flux fluxcd/flux \
  --set git.url=git@github.com:${GHUSER}/flux-get-started \
  --set 'git.path=namespaces\,workloads' \
  --namespace flux
```

3. Copy the public SSH key
```
fluxctl identity --k8s-fwd-ns flux
```

4. Setup the in GitHub (eg. `https://github.com/${GHUSER}/flux-get-started/settings/keys`)
Remember to enable `Allow write access`

5. Trigger sync
```
fluxctl sync --k8s-fwd-ns flux
```

6. View the applied change (you should see a `demo` namespace
```
kubectl get ns
```

## fluxcd playaround
1. copy `manifests-sample/podinfo-dep.yaml` and `manifests-sample/podinfo-svc.yaml` to `workloads/` in your `flux-get-started` repos; commit change and push

2. check deployment progress
`watch kubectl -n demo get pod`


## Install Helm operator

1. Install the CRD for HelmRelease
```
kubectl apply -f https://raw.githubusercontent.com/fluxcd/helm-operator/1.1.0/deploy/crds.yaml
```

2. Install Helm Operator via Helm
```
helm upgrade -i helm-operator fluxcd/helm-operator \
--set git.ssh.secretName=flux-git-deploy \
--set helm.versions=v3 \
--namespace flux
```

## Helm operator playaround

1. copy `releases/ghost.yaml` as `workloads/ghost.yaml` in your `flux-get-started` repos; commit change and push
OR running command
```
cat <<EOF | kubectl apply -f -
---
apiVersion: helm.fluxcd.io/v1
kind: HelmRelease
metadata:
  name: ghost
  namespace: demo
  annotations:
    fluxcd.io/automated: "false"
    fluxcd.io/tag.chart-image: glob:3.1.1-debian-9-*
spec:
  releaseName: ghost
  chart:
    git: ssh://git@github.com/fluxcd/flux-get-started
    ref: master
    path: charts/ghost
  values:
    image:
      repository: bitnami/ghost
      tag: 3.1.1-debian-9-r0
    persistence:
      enabled: false
    resources:
      requests:
        memory: 32Mi
        cpu: 10m
    service:
      type: ClusterIP
    mariadb:
      master:
        persistence:
          enabled: false
EOF
```
2. check Helm install progress
`watch kubectl -n demo get hr`

3. Port-forward the result
`kubectl -n demo port-forward --address 0.0.0.0 service/ghost 8080:80`

4. Open browser and check the result

## Set up Lens

1. install Lens at https://k8slens.dev/
    - Mac OS X (with homebrew installed): `brew cask install lens`

2. Add clusters with your KUBECONFIG

3. check it out

## Continuous Delivery

1. Check into the magic of annotations `fluxcd.io/automated: "true"`
- https://github.com/dictcp/flux-get-started/blob/master/workloads/podinfo-dep.yaml