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Template for creating a k3s cluster with k3sup backed by flux and sops

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Template for deploying k3s backed by Flux

Highly opinionated template for deploying a single k3s cluster with Ansible and 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 Ansible, Terraform and Flux SOPS integrations you'll be able to commit GPG encrypted secrets to your public repo.

Overview

👋  Introduction

The following components will be installed in your k3s cluster by default. They are only included to get a minimum viable cluster up and running. You are free to add / remove components to your liking but anything outside the scope of the below components are not supported by this template.

Feel free to read up on any of these technologies before you get started to be more familiar with them.

For provisioning the following tools will be used:

  • Ubuntu - this is a pretty universal operating system that supports running all kinds of home related workloads in Kubernetes
  • Ansible - this will be used to provision the Ubuntu operating system to be ready for Kubernetes and also to install k3s
  • Terraform - in order to help with the DNS settings this will be used to provision an already existing Cloudflare domain and DNS settings

📝  Prerequisites

💻  Systems

  • One or mote nodes with a fresh install of Ubuntu Server 20.04. These nodes can be bare metal or VMs.
  • A Cloudflare account with a domain, this will be managed by Terraform.
  • Some experience in debugging problems and a positive attitude ;)

🔧  Tools

📍 You should install the below CLI tools on your workstation. Make sure you pull in the latest versions.

Required

Tool Purpose
ansible Preparing Ubuntu for Kubernetes and installing k3s
direnv Exports env vars based on present working directory
flux Operator that manages your k8s cluster based on your Git repository
gnupg Encrypts and signs your data
go-task A task runner / simpler Make alternative written in Go
ipcalc Used to verify settings in the configure script
jq Used to verify settings in the configure script
kubectl Allows you to run commands against Kubernetes clusters
pinentry Allows GnuPG to read passphrases and PIN numbers
sops Encrypts k8s secrets with GnuPG
terraform Prepare a Cloudflare domain to be used with the cluster

Optional

Tool Purpose
helm Manage Kubernetes applications
kustomize Template-free way to customize application configuration
pre-commit Runs checks pre git commit
prettier Prettier is an opinionated code formatter.

⚠️  pre-commit

It is advisable to install pre-commit and the pre-commit hooks that come with this repository. sops-pre-commit will check to make sure you are not by accident committing your secrets un-encrypted.

After pre-commit is installed on your machine run:

pre-commit install-hooks

📂  Repository structure

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

  • base directory is the entrypoint to Flux
  • crds directory contains custom resource definitions (CRDs) that need to exist globally in your cluster before anything else exists
  • core directory (depends on crds) are important infrastructure applications (grouped by namespace) that should never be pruned by Flux
  • apps directory (depends on core) is where your common applications (grouped by namespace) could be placed, Flux will prune resources here if they are not tracked by Git anymore
cluster
├── apps
│   ├── default
│   ├── networking
│   └── system-upgrade
├── base
│   └── flux-system
├── core
│   ├── cert-manager
│   ├── metallb-system
│   ├── namespaces
│   └── system-upgrade
└── crds
    └── cert-manager

🚀  Lets go!

Very first step will be to create a new repository by clicking the Use this template button on this page.

Clone the repo to you local workstation and cd into it.

📍 All of the below commands are run on your local workstation, not on any of your cluster nodes.

🔐  Setting up GnuPG keys

📍 Here we will create a personal and a Flux GPG key. Using SOPS with GnuPG allows us to encrypt and decrypt secrets.

  1. Create a Personal GPG Key, password protected, and export the fingerprint. It's strongly encouraged to back up this key somewhere safe so you don't lose it.
export GPG_TTY=$(tty)
export PERSONAL_KEY_NAME="First name Last name (location) <email>"

gpg --batch --full-generate-key <<EOF
Key-Type: 1
Key-Length: 4096
Subkey-Type: 1
Subkey-Length: 4096
Expire-Date: 0
Name-Real: ${PERSONAL_KEY_NAME}
EOF

gpg --list-secret-keys "${PERSONAL_KEY_NAME}"
# pub   rsa4096 2021-03-11 [SC]
#       772154FFF783DE317KLCA0EC77149AC618D75581
# uid           [ultimate] k8s@home (Macbook) <[email protected]>
# sub   rsa4096 2021-03-11 [E]
  1. Create a Flux GPG Key and export the fingerprint
export GPG_TTY=$(tty)
export FLUX_KEY_NAME="Cluster name (Flux) <email>"

gpg --batch --full-generate-key <<EOF
%no-protection
Key-Type: 1
Key-Length: 4096
Subkey-Type: 1
Subkey-Length: 4096
Expire-Date: 0
Name-Real: ${FLUX_KEY_NAME}
EOF

gpg --list-secret-keys "${FLUX_KEY_NAME}"
# pub   rsa4096 2021-03-11 [SC]
#       AB675CE4CC64251G3S9AE1DAA88ARRTY2C009E2D
# uid           [ultimate] Home cluster (Flux) <[email protected]>
# sub   rsa4096 2021-03-11 [E]
  1. You will need the Fingerprints in the configuration section below. For example, in the above steps you will need 772154FFF783DE317KLCA0EC77149AC618D75581 and AB675CE4CC64251G3S9AE1DAA88ARRTY2C009E2D

☁️  Global Cloudflare API Key

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

  1. Head over to Cloudflare and create a API key by going here.

  2. Under the API Keys section, create a global API Key.

  3. Use the API Key in the configuration section below.

📄  Configuration

📍 The .config.env file contains necessary configuration files that are needed by Ansible, Terraform and Flux.

  1. Copy the .config.sample.env to .config.env and start filling out all the environment variables. All are required and read the comments they will explain further what is required.

  2. Once that is done, verify the configuration is correct by running ./configure.sh --verify

  3. If you do not encounter any errors run ./configure.sh to start having the script wire up the templated files and place them where they need to be.

⚡  Preparing Ubuntu with Ansible

📍 Here we will be running a Ansible Playbook to prepare Ubuntu for running a Kubernetes cluster.

  1. Ensure you are able to SSH into you nodes from your workstation with using your private ssh key. This is how Ansible is able to connect to your remote nodes.

  2. Install the deps by running task ansible:deps

  3. Verify Ansible can view your config by running task ansible:list

  4. Verify Ansible can ping your nodes by running task ansible:ping

  5. Finally, run the Ubuntu Prepare playbook by running task ansible:playbook:ubuntu-prepare

  6. If everything goes as planned you should see Ansible running the Ubuntu Prepare Playbook against your nodes.

⛵  Installing k3s with Ansible

📍 Here we will be running a Ansible Playbook to install k3s with this wonderful k3s Ansible galaxy role. After completion, Ansible will drop a kubeconfig in /tmp/kubeconfig for use with interacting with your cluster with kubectl. This file should be manually copied to the root of your repository.

  1. Verify Ansible can view your config by running task ansible:list

  2. Verify Ansible can ping your nodes by running task ansible:adhoc:ping

  3. Run the k3s install playbook by running task ansible:playbook:k3s-install

  4. If everything goes as planned you should see Ansible running the k3s install Playbook against your nodes.

  5. Copy the kubeconfig file from /tmp to your repository.

  6. Verify the nodes are online

kubectl --kubeconfig=./kubeconfig get nodes
# NAME           STATUS   ROLES                       AGE     VERSION
# k8s-0          Ready    control-plane,master      4d20h   v1.21.5+k3s1
# k8s-1          Ready    worker                    4d20h   v1.21.5+k3s1

🔹  GitOps with Flux

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

  1. Verify Flux can be installed
flux --kubeconfig=./kubeconfig check --pre
# ► checking prerequisites
# ✔ kubectl 1.21.5 >=1.18.0-0
# ✔ Kubernetes 1.21.5+k3s1 >=1.16.0-0
# ✔ prerequisites checks passed
  1. Pre-create the flux-system namespace
kubectl --kubeconfig=./kubeconfig create namespace flux-system --dry-run=client -o yaml | kubectl --kubeconfig=./kubeconfig apply -f -
  1. Add the Flux GPG key in-order for Flux to decrypt SOPS secrets
source .config.env
gpg --export-secret-keys --armor "${BOOTSTRAP_FLUX_KEY_FP}" |
kubectl --kubeconfig=./kubeconfig create secret generic sops-gpg \
    --namespace=flux-system \
    --from-file=sops.asc=/dev/stdin

📍 Variables defined in ./cluster/base/cluster-secrets.sops.yaml and ./cluster/base/cluster-settings.sops.yaml will be usable anywhere in your YAML manifests under ./cluster

  1. Verify all the above files are encrypted with SOPS

  2. If you verified all the secrets are encrypted, you can delete the tmpl directory now

  3. Push you changes to git

git add -A
git commit -m "initial commit"
git push
  1. Install Flux

📍 Due to race conditions with the Flux CRDs you will have to run the below command twice. There should be no errors on this second run.

kubectl --kubeconfig=./kubeconfig apply --kustomize=./cluster/base/flux-system
# namespace/flux-system configured
# customresourcedefinition.apiextensions.k8s.io/alerts.notification.toolkit.fluxcd.io created
# ...
# unable to recognize "./cluster/base/flux-system": no matches for kind "Kustomization" in version "kustomize.toolkit.fluxcd.io/v1beta1"
# unable to recognize "./cluster/base/flux-system": no matches for kind "GitRepository" in version "source.toolkit.fluxcd.io/v1beta1"
# unable to recognize "./cluster/base/flux-system": no matches for kind "HelmRepository" in version "source.toolkit.fluxcd.io/v1beta1"
# unable to recognize "./cluster/base/flux-system": no matches for kind "HelmRepository" in version "source.toolkit.fluxcd.io/v1beta1"
# unable to recognize "./cluster/base/flux-system": no matches for kind "HelmRepository" in version "source.toolkit.fluxcd.io/v1beta1"
# unable to recognize "./cluster/base/flux-system": no matches for kind "HelmRepository" in version "source.toolkit.fluxcd.io/v1beta1"
  1. Verify Flux components are running in the cluster
kubectl --kubeconfig=./kubeconfig get 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

🎉 Congratulations you have a Kubernetes cluster managed by Flux, your Git repository is driving the state of your cluster.

☁️  Configure Cloudflare DNS with Terraform

📍 Review the Terraform scripts under ./terraform/cloudflare/ and make sure you understand what it's doing (no really review it). If your domain already has existing DNS records be sure to export those DNS settings before you continue. Ideally you can update the terraform script to manage DNS for all records if you so choose to.

  1. Pull in the Terraform deps by running task terraform:init

  2. Review the changes Terraform will make to your Cloudflare domain by running task terraform:plan

  3. Finally have Terraform execute the task by running task terraform:apply

If Terraform was ran successfully head over to your browser and you should be able to access https://hajimari.${BOOTSTRAP_CLOUDFLARE_DOMAIN}

📣  Post installation

direnv

This is a great tool to export environment variables depending on what your present working directory is, head over to their installation guide and don't forget to hook it into your shell!

When this is done you no longer have to use --kubeconfig=./kubeconfig in your kubectl, flux or helm commands.

VSCode SOPS extension

VSCode SOPS is a neat little plugin for those using VSCode. It will automatically decrypt you SOPS secrets when you click on the file in the editor and encrypt them when you save and exit the file.

👉  Debugging

Manually sync Flux with your Git repository

flux --kubeconfig=./kubeconfig reconcile source git flux-system
# ► annotating GitRepository flux-system in flux-system namespace
# ✔ GitRepository annotated
# ◎ waiting for GitRepository reconciliation
# ✔ GitRepository reconciliation completed
# ✔ fetched revision main/943e4126e74b273ff603aedab89beb7e36be4998

Show the health of you kustomizations

kubectl --kubeconfig=./kubeconfig get kustomization -A
# NAMESPACE     NAME          READY   STATUS                                                             AGE
# flux-system   apps          True    Applied revision: main/943e4126e74b273ff603aedab89beb7e36be4998    3d19h
# flux-system   core          True    Applied revision: main/943e4126e74b273ff603aedab89beb7e36be4998    4d6h
# flux-system   crds          True    Applied revision: main/943e4126e74b273ff603aedab89beb7e36be4998    4d6h
# flux-system   flux-system   True    Applied revision: main/943e4126e74b273ff603aedab89beb7e36be4998    4d6h

Show the health of your main Flux GitRepository

flux --kubeconfig=./kubeconfig get sources git
# NAME           READY	MESSAGE                                                            REVISION                                         SUSPENDED
# flux-system    True 	Fetched revision: main/943e4126e74b273ff603aedab89beb7e36be4998    main/943e4126e74b273ff603aedab89beb7e36be4998    False

Show the health of your HelmReleases

flux --kubeconfig=./kubeconfig get helmrelease -A
# NAMESPACE   	    NAME                  	READY	MESSAGE                         	REVISION	SUSPENDED
# cert-manager	    cert-manager          	True 	Release reconciliation succeeded	v1.5.2  	False
# default        	hajimari                True 	Release reconciliation succeeded	1.1.1   	False
# networking  	    ingress-nginx       	True 	Release reconciliation succeeded	3.30.0  	False

Show the health of your HelmRepositorys

flux --kubeconfig=./kubeconfig get sources helm -A
# NAMESPACE  	NAME                 READY	MESSAGE                                                   	REVISION                                	SUSPENDED
# flux-system	bitnami-charts       True 	Fetched revision: 0ec3a3335ff991c45735866feb1c0830c4ed85cf	0ec3a3335ff991c45735866feb1c0830c4ed85cf	False
# flux-system	hajimari-charts      True 	Fetched revision: 1b24af9c5a1e3da91618d597f58f46a57c70dc13	1b24af9c5a1e3da91618d597f58f46a57c70dc13	False
# flux-system	ingress-nginx-charts True 	Fetched revision: 45669a3117fc93acc09a00e9fb9b4445e8990722	45669a3117fc93acc09a00e9fb9b4445e8990722	False
# flux-system	jetstack-charts      True 	Fetched revision: 7bad937cc82a012c9ee7d7a472d7bd66b48dc471	7bad937cc82a012c9ee7d7a472d7bd66b48dc471	False
# flux-system	k8s-at-home-charts   True 	Fetched revision: 1b24af9c5a1e3da91618d597f58f46a57c70dc13	1b24af9c5a1e3da91618d597f58f46a57c70dc13	False

Flux has a wide range of CLI options available be sure to run flux --help to view more!

🤖  Automation

  • Renovate is a very useful tool that when configured will start to create PRs in your Github repository when Docker images, Helm charts or anything else that can be tracked has a newer version. The configuration for renovate is located here.

  • system-upgrade-controller will watch for new k3s releases and upgrade your nodes when new releases are found.

There's also a couple Github workflows included in this repository that will help automate some processes.

Keep your repository up-to-date with this template

At some point you may want to update your Git repository with some commit from this repository. The following is one method to achieve this.

  1. Add this repository as an additional remote
git remote add tmpl [email protected]:k8s-at-home/template-cluster-k3s.git
  1. Fetch all the branches
git fetch tmpl
  1. List the commits from this repository
git log tmpl/main
  1. Pick the commit you want to bring over to your repository
git cherry-pick ce67a3c
  1. Push the changes up to your Git remote
git push origin main

❔  What's next

The world is your cluster, try installing another application or if you have a NAS and want storage back by that check out the helm charts for democratic-csi, csi-driver-nfs or nfs-subdir-external-provisioner.

If you plan on exposing your ingress to the world from your home. Checkout our rough guide to run a k8s CronJob to update DDNS.

🤝  Thanks

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

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Template for creating a k3s cluster with k3sup backed by flux and sops

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