Template for deploying k3s and Flux backed by SOPS secrets

Template for creating a k3s cluster with k3sup.

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.

The components installed by default are listed below and can be replaced to your liking. They are only included to get a minimum viable cluster up and running.

k3s
flannel
local-path-provisioner
flux
metallb
cert-manager with Cloudflare DNS challenge
ingress-nginx
homer

📝 Prerequisites

💻 Nodes

Bare metal or VMs with any modern operating system like Ubuntu, Debian or CentOS.

🔧 Tools

Tool	Purpose	Minimum version	Required
k3sup	Tool to install k3s on your nodes	`0.10.2`	✅
kubectl	Allows you to run commands against Kubernetes clusters	`1.21.0`	✅
flux	Operator that manages your k8s cluster based on your Git repository	`0.12.3`	✅
SOPS	Encrypts k8s secrets with GnuPG	`3.7.1`	✅
GnuPG	Encrypts and signs your data	`2.2.27`	✅
pinentry	Allows GnuPG to read passphrases and PIN numbers	`1.1.1`	✅
direnv	Exports env vars based on present working directory	`2.28.0`	❌
pre-commit	Runs checks during `git commit`	`2.12.0`	❌
kustomize	Template-free way to customize application configuration	`4.1.0`	❌
helm	Manage Kubernetes applications	`3.5.4`	❌

⚠️ Pre-installation

It's very important and I cannot stress enough, make sure you are not pushing your secrets un-encrypted to a public Git repo.

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 commiting your secrets un-encrypted.

After pre-commit is installed on your machine run:

pre-commit install-hooks

🚀 Lets go!

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

🔐 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.

Create a Personal GPG Key, password protected, and export the fingerprint

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) <k8s-at-home@gmail.com>
# sub   rsa4096 2021-03-11 [E]

export PERSONAL_KEY_FP=772154FFF783DE317KLCA0EC77149AC618D75581

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) <k8s-at-home@gmail.com>
# sub   rsa4096 2021-03-11 [E]

export FLUX_KEY_FP=AB675CE4CC64251G3S9AE1DAA88ARRTY2C009E2D

⛵ Installing k3s with k3sup

Here we will be install k3s with k3sup.

Ensure you are able to SSH into you nodes with using your private ssh key. This is how k3sup is able to connect to your remote node.
Install the master node

k3sup install \
    --host=169.254.1.1 \
    --user=k8s-at-home \
    --k3s-version=v1.20.5+k3s1 \
    --k3s-extra-args="--disable servicelb --disable traefik"

Join a worker node(s) (optional)

k3sup join \
    --host=169.254.1.2 \
    --server-host=169.254.1.1 \
    --k3s-version=v1.20.5+k3s1 \
    --user=k8s-at-home

Verify the nodes are online

kubectl --kubeconfig=./kubeconfig get nodes
# NAME           STATUS   ROLES                       AGE     VERSION
# k8s-master-a   Ready    control-plane,master      4d20h   v1.20.5+k3s1
# k8s-worker-a   Ready    worker                    4d20h   v1.20.5+k3s1

🔹 GitOps with Flux

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

Pre-create the flux-system namespace

kubectl --kubeconfig=./kubeconfig create namespace flux-system --dry-run=client -o yaml | kubectl apply -f -

Add the Flux GPG key in-order for Flux to decrypt SOPS secrets

gpg --export-secret-keys --armor "${FLUX_KEY_FP}" |
kubectl --kubeconfig=./kubeconfig create secret generic sops-gpg \
    --namespace=flux-system \
    --from-file=sops.asc=/dev/stdin

Update files using envsubst or by updating the files listed below manually

export BOOTSTRAP_GITHUB_REPOSITORY="k8s-at-home/home-cluster"
export BOOTSTRAP_METALLB_LB_RANGE="169.254.1.10-169.254.1.20"
export BOOTSTRAP_DOMAIN="k8s-at-home.com"
export BOOTSTRAP_DOMAIN_CERT="k8s-at-home"
export BOOTSTRAP_CLOUDFLARE_TOKEN="dsKq41iLAbXE37GV"
export BOOTSTRAP_INGRESS_NGINX_LB="169.254.1.10"

envsubst < ./tmpl/.sops.yaml > ./.sops.yaml
envsubst < ./tmpl/cluster-secrets.yaml > ./cluster/cluster-secrets.yaml
envsubst < ./tmpl/cluster-settings.yaml > ./cluster/cluster-settings.yaml
envsubst < ./tmpl/gotk-sync.yaml > ./cluster/base/flux-system/gotk-sync.yaml
envsubst < ./tmpl/secret.enc.yaml > ./cluster/core/infrastructure/cert-manager/secret.enc.yaml

Verify all the above files have the correct information present
Encrypt cluster/cluster-secrets.yaml and cert-manager/secret.enc.yaml with SOPS

export GPG_TTY=$(tty)
sops --encrypt --in-place ./cluster/base/cluster-secrets.yaml
sops --encrypt --in-place ./cluster/core/cert-manager/secret.enc.yaml

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

Verify all the above files are encrypted with SOPS
Push you changes to git

git add -A
git commit -m "initial commit"
git push

Install Flux

kubectl --kubeconfig=./kubeconfig --kustomize=./cluster/base/flux-system

📣 Post installation

Verify ingress

If your cluster is not accessible to outside world you can update your hosts file to verify the ingress controller is working.

sudo echo "${BOOTSTRAP_INGRESS_NGINX_LB} ${BOOTSTRAP_DOMAIN} homer.${BOOTSTRAP_DOMAIN}" >> /etc/hosts

Head over to your browser and you should be able to access https://homer.${BOOTSTRAP_DOMAIN}

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!

Delete Flux GPG key

Since there is a GPG key specifically for Flux you can remove the secret key from your personal machine.

gpg --delete-secret-keys "${FLUX_KEY_FP}"

VSCode SOPS extension

Here's 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 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   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	v1.3.0  	False
# home        	homer                 	True 	Release reconciliation succeeded	4.2.0   	False
# networking  	ingress-nginx       	True 	Release reconciliation succeeded	3.29.0  	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	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!

❔ 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 democratic-csi, csi-driver-nfs or nfs-subdir-external-provisioner.

🤝 Thanks

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

dcplaya/template-cluster-k3s