Template for deploying k3s backed by Flux

Highly opinionated template for deploying a single k3s cluster with Terraform backed by Flux and SOPS.

The purpose here is to showcase how you can deploy an entire Kubernetes cluster and show it off to the world using the GitOps tool Flux. When completed, your Git repository will be driving the state of your Kubernetes cluster. In addition with the help of the Terraform and Flux SOPS integrations you'll be able to commit Age encrypted secrets to your public repo.

Overview

Introduction
Prerequisites
Repository structure
Lets go!
Post installation
Troubleshooting
What's next
Thanks

👋 Introduction

The following components will be installed in your k3s cluster by default. Most are only included to get a minimum viable cluster up and running.

flux - GitOps operator for managing Kubernetes clusters from a Git repository
metallb - Load balancer for Kubernetes services
cert-manager - Operator to request SSL certificates and store them as Kubernetes resources
external-dns - Operator to publish DNS records to your DNS providers based on Kubernetes ingresses
traefik - Kubernetes ingress controller used for a HTTP reverse proxy of Kubernetes ingresses
local-path-provisioner - provision persistent local storage with Kubernetes

Additional applications include hajimari, error-pages, echo-server, system-upgrade-controller, reloader, and kured

For provisioning the following tools will be used:

Terraform - Provisions all nodes and API keys needed in the cluster.

📝 Prerequisites

First and foremost some experience in debugging/troubleshooting problems and a positive attitude is required ;)

📚 Reading material

Organizing Cluster Access Using kubeconfig Files

💻 Systems

One or more nodes with a fresh install of Proxmox
- These nodes should be AMD64 bare metal.
- An odd number of control plane nodes, greater than or equal to 3 is required if deploying more than one control plane node.
A GCP account with a domain, this will be managed by Terraform and external-dns.

📍 It is recommended to have 3 master nodes for a highly available control plane.

📂 Repository structure

The Git repository contains the following directories under kubernetes and are ordered below by how Flux will apply them.

📁 kubernetes      # Kubernetes cluster defined as code
├─📁 bootstrap     # Flux installation
├─📁 flux          # Main Flux configuration of repository
└─📁 apps          # Apps deployed into the cluster grouped by namespace

🚀 Lets go

🔧 Workstation Tools

📍 Install the most recent version of the CLI tools below. If you are having trouble with future steps, it is very likely you don't have the most recent version of these CLI tools, !especially sops AND yq!.

Install the following CLI tools on your workstation, and go-task

Below will be automatically installed as part of the further steps.

* Required: [age](https://github.com/FiloSottile/age), [flux](https://toolkit.fluxcd.io/), [weave-gitops](https://docs.gitops.weave.works/docs/installation/weave-gitops/), [go-task](https://github.com/go-task/task), [direnv](https://github.com/direnv/direnv), [ipcalc](http://jodies.de/ipcalc), [jq](https://stedolan.github.io/jq/), [kubectl](https://kubernetes.io/docs/tasks/tools/), [python-pip3](https://pypi.org/project/pip/), [pre-commit](https://github.com/pre-commit/pre-commit), [sops v3](https://github.com/mozilla/sops), [terraform](https://www.terraform.io), [yq v4](https://github.com/mikefarah/yq)

* Recommended: [helm](https://helm.sh/), [kustomize](https://github.com/kubernetes-sigs/kustomize), [stern](https://github.com/stern/stern), [yamllint](https://github.com/adrienverge/yamllint)

This guide heavily relies on go-task as a framework for setting things up. It is advised to learn and understand the commands it is running under the hood.
[Homebrew] Install workstation dependencies
```
go-task init
```

⚠️ pre-commit

It is advisable to install pre-commit and the pre-commit hooks that come with this repository.

Enable Pre-Commit
```
go-task precommit:init
```
Update Pre-Commit, though it will occasionally make mistakes, so verify its results.
```
go-task precommit:update
```

🔐 Setting up Age

📍 Here we will create a Age Private and Public key. Using SOPS with Age allows us to encrypt secrets and use them in Terraform and Flux.

Create a Age Private / Public Key
```
go-task age
```
Fill out the Age public key in the appropriate variable in configuration section below, note the public key should start with age...

☁️ GCP API Key

In order to use Terraform and cert-manager with the GCP DNS challenge you will need to create a API key.

Head over to GCP and create a API key by going here
Either create a service account, or use an existing with the proper permissions.
Generate a .json key to use with the account.

📄 Configuration

📍 The .config.env file contains necessary configuration that is needed by Terraform and Flux.

Copy the .config.sample.env to .config.env and start filling out all the environment variables.

All are required unless otherwise noted in the comments.
```
cp .config.sample.env .config.env
```
Once that is done, verify the configuration is correct by running:
```
go-task verify
```
If you do not encounter any errors run start having the script wire up the templated files and place them where they need to be.
```
go-task configure
```

☁️ Configuring Infrastructure with Terraform

📍 Review the Terraform scripts under ./terraform/infra/ and make sure you understand what it's doing (no really review it).

Pull in the Terraform deps
```
go-task terraform:init
```
Review the changes Terraform will make
```
go-task terraform:plan
```
Have Terraform apply your settings
```
go-task terraform:apply
```

The cluster application external-dns will be managing the rest of the DNS records you will need.

🔹 GitOps with Flux

📍 Here we will be installing flux after some quick bootstrap steps.

Verify Flux can be installed

go-task cluster:verify
# ► checking prerequisites
# ✔ kubectl 1.21.5 >=1.18.0-0
# ✔ Kubernetes 1.21.5+k3s1 >=1.16.0-0
# ✔ prerequisites checks passed

Push you changes to git

📍 Verify all the *.sops.yaml and *.sops.yml files under the ./kubernetes, and ./terraform folders are encrypted with SOPS
```
git add -A
git commit -m "Initial commit :rocket:"
git push
```

Install Flux and sync the cluster to the Git repository

go-task cluster:install
# namespace/flux-system configured
# customresourcedefinition.apiextensions.k8s.io/alerts.notification.toolkit.fluxcd.io created

Verify Flux components are running in the cluster

go-task cluster:pods -- -n flux-system
# NAME                                       READY   STATUS    RESTARTS   AGE
# helm-controller-5bbd94c75-89sb4            1/1     Running   0          1h
# kustomize-controller-7b67b6b77d-nqc67      1/1     Running   0          1h
# notification-controller-7c46575844-k4bvr   1/1     Running   0          1h
# source-controller-7d6875bcb4-zqw9f         1/1     Running   0          1h

🎤 Verification Steps

Mic check, 1, 2 - In a few moments applications should be lighting up like a Christmas tree 🎄

You are able to run all the commands below with one task

go-task cluster:resources

View the Flux Git Repositories
```
go-task cluster:gitrepositories
```
View the Flux kustomizations
```
go-task cluster:kustomizations
```
View all the Flux Helm Releases
```
go-task cluster:helmreleases
```
View all the Flux Helm Repositories
```
go-task cluster:helmrepositories
```
View all the Pods
```
go-task cluster:pods
```
View all the certificates and certificate requests
```
go-task cluster:certificates
```
View all the ingresses
```
go-task cluster:ingresses
```

🏆 Congratulations if all goes smooth you'll have a Kubernetes cluster managed by Flux, your Git repository is driving the state of your cluster.

🧠 Now it's time to pause and go get some coffee ☕ because next is describing how DNS is handled.

📣 Post installation

🌱 Environment

direnv will make it so anytime you cd to your repo's directory it export the required environment variables (e.g. KUBECONFIG). To set this up make sure you hook it into your shell and after that is done, run direnv allow while in your repos directory.

🌐 DNS

📍 The external-dns application created in the networking namespace will handle creating public DNS records. By default, echo-server and the flux-webhook are the only public domain exposed on your domain. In order to make additional applications public you must set an ingress annotation (external-dns.alpha.kubernetes.io/target) like done in the HelmRelease for echo-server. You do not need to use Terraform to create additional DNS records unless you need a record outside the purposes of your Kubernetes cluster (e.g. setting up MX records).

k8s_gateway is deployed on the IP choosen for ${BOOTSTRAP_METALLB_K8S_GATEWAY_ADDR}. Inorder to test DNS you can point your clients DNS to the ${BOOTSTRAP_METALLB_K8S_GATEWAY_ADDR} IP address and load https://hajimari.${BOOTSTRAP_CLOUDFLARE_DOMAIN} in your browser.

You can also try debugging with the command dig, e.g. dig @${BOOTSTRAP_METALLB_K8S_GATEWAY_ADDR} hajimari.${BOOTSTRAP_CLOUDFLARE_DOMAIN} and you should get a valid answer containing your ${BOOTSTRAP_METALLB_INGRESS_ADDR} IP address.

If your router (or Pi-Hole, Adguard Home or whatever) supports conditional DNS forwarding (also know as split-horizon DNS) you may have DNS requests for ${SECRET_DOMAIN} only point to the ${BOOTSTRAP_METALLB_K8S_GATEWAY_ADDR} IP address. This will ensure only DNS requests for ${SECRET_DOMAIN} will only get routed to your k8s_gateway service thus providing DNS resolution to your cluster applications/ingresses.

To access services from the outside world port forwarded 80 and 443 in your router to the ${BOOTSTRAP_METALLB_INGRESS_ADDR} IP, in a few moments head over to your browser and you should be able to access https://echo-server.${BOOTSTRAP_CLOUDFLARE_DOMAIN} from a device outside your LAN.

Now if nothing is working, that is expected. This is DNS after all!

🤖 Renovatebot

Renovatebot will scan your repository and offer PRs when it finds dependencies out of date. Common dependencies it will discover and update are Flux, Terraform Providers, Kubernetes Helm Charts, Kubernetes Container Images, Pre-commit hooks updates, and more!

The base Renovate configuration provided in your repository can be view at .github/renovate.json5. If you notice this only runs on weekends and you can change the schedule to anything you want or simply remove it.

To enable Renovate on your repository, click the 'Configure' button over at their Github app page and choose your repository. Over time Renovate will create PRs for out-of-date dependencies it finds. Any merged PRs that are in the kubernetes directory Flux will deploy.

🪝 Github Webhook

Flux is pull-based by design meaning it will periodically check your git repository for changes, using a webhook you can enable Flux to update your cluster on git push. In order to configure Github to send push events from your repository to the Flux webhook receiver you will need two things:

Webhook URL - Your webhook receiver will be deployed on https://flux-webhook.${BOOTSTRAP_CLOUDFLARE_DOMAIN}/hook/:hookId. In order to find out your hook id you can run the following command:

kubectl -n flux-system get receiver/github-receiver
# NAME              AGE    READY   STATUS
# github-receiver   6h8m   True    Receiver initialized with URL: /hook/12ebd1e363c641dc3c2e430ecf3cee2b3c7a5ac9e1234506f6f5f3ce1230e123

So if my domain was onedr0p.com the full url would look like this:

https://flux-webhook.onedr0p.com/hook/12ebd1e363c641dc3c2e430ecf3cee2b3c7a5ac9e1234506f6f5f3ce1230e123

Webhook secret - Your webhook secret can be found by decrypting the secret.sops.yaml using the following command:
```
sops -d ./kubernetes/apps/flux-system/addons/webhooks/github/secret.sops.yaml | yq .stringData.token
```
Note: Don't forget to update the BOOTSTRAP_FLUX_GITHUB_WEBHOOK_SECRET variable in your .config.env file so it matches the generated secret if applicable

Now that you have the webhook url and secret, it's time to set everything up on the Github repository side. Navigate to the settings of your repository on Github, under "Settings/Webhooks" press the "Add webhook" button. Fill in the webhook url and your secret.

💾 Storage

Rancher's local-path-provisioner is a great start for storage but soon you might find you need more features like replicated block storage, or to connect to a NFS/SMB/iSCSI server. Check out the projects below to read up more on some storage solutions that might work for you.

rook-ceph
longhorn
openebs
nfs-subdir-external-provisioner
democratic-csi
csi-driver-nfs
synology-csi

🔏 Authenticate Flux over SSH

Authenticating Flux to your git repository has a couple benefits like using a private git repository and/or using the Flux Image Automation Controllers.

By default this template only works on a public GitHub repository, it is advised to keep your repository public.

The benefits of a public repository include:

Debugging or asking for help, you can provide a link to a resource you are having issues with.
Adding a topic to your repository of k8s-at-home to be included in the k8s-at-home-search. This search helps people discover different configurations of Helm charts across others Flux based repositories.

Expand to read guide on adding Flux SSH authentication

Generate new SSH key:

ssh-keygen -t ecdsa -b 521 -C "github-deploy-key" -f ./kubernetes/bootstrap/github-deploy.key -q -P ""

Paste public key in the deploy keys section of your repository settings

Create sops secret in ./kubernetes/bootstrap/github-deploy-key.sops.yaml with the contents of:

apiVersion: v1
kind: Secret
metadata:
    name: github-deploy-key
    namespace: flux-system
stringData:
    # 3a. Contents of github-deploy-key
    identity: |
        -----BEGIN OPENSSH PRIVATE KEY-----
            ...
        -----END OPENSSH PRIVATE KEY-----
    # 3b. Output of curl --silent https://api.github.com/meta | jq --raw-output '"github.com "+.ssh_keys[]'
    known_hosts: |
        github.com ssh-ed25519 ...
        github.com ecdsa-sha2-nistp256 ...
        github.com ssh-rsa ...

Encrypt secret:

sops --encrypt --in-place ./kubernetes/bootstrap/github-deploy-key.sops.yaml

Apply secret to cluster:

sops --decrypt ./kubernetes/bootstrap/github-deploy-key.sops.yaml | kubectl apply -f -

Update ./kubernetes/flux/config/cluster.yaml:

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: GitRepository
metadata:
  name: home-kubernetes
  namespace: flux-system
spec:
  interval: 10m
  # 6a: Change this to your user and repo names
  url: ssh://git@github.com/$user/$repo
  ref:
    branch: main
  secretRef:
    name: github-deploy-key

Commit and push changes
Force flux to reconcile your changes
```
go-task cluster:reconcile
```
Verify git repository is now using SSH:
```
go-task cluster:gitrepositories
```
Optionally set your repository to Private in your repository settings.

💨 Kubernetes Dashboard

Included in your cluster is the Kubernetes Dashboard. Inorder to log into this you will have to get the secret token from the cluster using the command below.

kubectl -n monitoring get secret kubernetes-dashboard -o jsonpath='{.data.token}' | base64 -d

You should be able to access the dashboard at https://kubernetes.${SECRET_DOMAIN}

🐛 Debugging

Below is a general guide on trying to debug an issue with an resource or application. For example, if a workload/resource is not showing up or a pod has started but in a CrashLoopBackOff or Pending state.

Start by checking all Flux Kustomizations and verify they are healthy.

flux get ks -A

Then check all the Flux Helm Releases and verify they are healthy.

flux get hr -A

Then check the if the pod is present.

kubectl -n <namespace> get pods

Then check the logs of the pod if its there.

kubectl -n <namespace> logs <pod-name> -f

Note: If a resource exists, running kubectl -n <namespace> describe <resource> <name> might give you insight into what the problem(s) could be.

Resolving problems that you have could take some tweaking of your YAML manifests in order to get things working, other times it could be a external factor like permissions on NFS. If you are unable to figure out your problem see the help section below.

👉 Help

Make a post in this repository's GitHub Discussions.
Start a thread in the support or flux-cluster-template channel in the k8s@home Discord server.

❔ What's next

The world is your cluster, have at it!

🤝 Thanks

Big shout out to all the authors and contributors to the projects that we are using in this repository.

Many thanks to the original by onedr0p @whazor created this website as a creative way to search Helm Releases across GitHub. You may use it as a means to get ideas on how to configure an applications' Helm values.

Provide feedback

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README.md

README.md

Template for deploying k3s backed by Flux

Overview

👋 Introduction

📝 Prerequisites

📚 Reading material

💻 Systems

📂 Repository structure

🚀 Lets go

🔧 Workstation Tools

⚠️ pre-commit

🔐 Setting up Age

☁️ GCP API Key

📄 Configuration

☁️ Configuring Infrastructure with Terraform

🔹 GitOps with Flux

🎤 Verification Steps

📣 Post installation

🌱 Environment

🌐 DNS

🤖 Renovatebot

🪝 Github Webhook

💾 Storage

🔏 Authenticate Flux over SSH

💨 Kubernetes Dashboard

🐛 Debugging

👉 Help

❔ What's next

🤝 Thanks

Files

README.md

Latest commit

History

README.md

File metadata and controls

Template for deploying k3s backed by Flux

Overview

👋 Introduction

📝 Prerequisites

📚 Reading material

💻 Systems

📂 Repository structure

🚀 Lets go

🔧 Workstation Tools

⚠️ pre-commit

🔐 Setting up Age

☁️ GCP API Key

📄 Configuration

☁️ Configuring Infrastructure with Terraform

🔹 GitOps with Flux

🎤 Verification Steps

📣 Post installation

🌱 Environment

🌐 DNS

🤖 Renovatebot

🪝 Github Webhook

💾 Storage

🔏 Authenticate Flux over SSH

💨 Kubernetes Dashboard

🐛 Debugging

👉 Help

❔ What's next

🤝 Thanks