home-cluster/README.md

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

:memo:  Prerequisites

:computer:  Nodes

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

:wrench:  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 [+]	Keeps formatting consistency across your files and ensures you do not commit un-encrypted secrets to your repository	2.12.0	❌
kustomize [+]	Template-free way to customize application configuration	4.1.0	❌

:rocket:  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.

I would start off by making your repository private until you are certain there are no leaks before showing it off to the world.

:rocket:  Lets go!

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

:key:  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

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

2. 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: ${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

:sailboat:  Installing k3s with k3sup

Here we will be install k3s with k3sup.

1. 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.

2. 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"

3. 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

4. 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.

1. Pre-create the flux-system namespace

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

1. 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

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

4. Verify all the above files have the correct information present

5. 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/infrastructure/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

6. Verify all the above files are encrypted with SOPS

7. Push you changes to git

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

8. Install Flux

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

Post installation

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 SOPS secrets un-encrypted.

After pre-commit is installed run:

pre-commit install-hooks

What's next?

The world is your pod, try installing a application!

:handshake:  Thanks

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