Flux/SOPS/minikube sandbox

With thanks to k8s-at-home

This is my personal experiment/adventure/science project/playground repo for a local minikube cluster, backed by Flux and SOPS. In "Production" (that is, for my home), I run k3s which is provided and customized by TrueNAS SCALE.

The purpose here is to closely resemble that "Production" state with respect to Kubernetes, obviously without the zfs integration and TrueNAS-specific components; the focus therefore is the workflow: GitOps, provided via Flux. This repo drives the state of the cluster, and the Flux SOPS integration allows for storage of secrets in a public repo.

👋 Introduction

Base components preserved in this repo:

local-path-provisioner
flux
cert-manager with Cloudflare DNS challenge

📝 Prerequisites

💻 Nodes

This is intended for minikube or TrueNAS SCALE installations, but should work on most single node Kubernetes distributions? For k3s, you may want to bring (back) in the system-upgrade and metallb components - see the original template.

🔧 Tools

📍 You need to install the required CLI tools listed below on your workstation.

Tool	Purpose	Minimum version	Required
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`	✅
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-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

📂 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

🔐 Setting up GnuPG keys

Get public fingerprint for personal GPG key

export GPG_TTY=$(tty)
export PERSONAL_KEY_NAME="First name Last name <email>"

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 cluster-specific 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

☁️ Cloudflare API Token

📍 You may skip this step, however make sure to export dummy data on item 8 in the below list.

...Be aware you will not have a valid SSL cert until cert-manager is configured correctly

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

Head over to Cloudflare and create a API token by going here.
Click the blue Create Token button
Scroll down and create a Custom Token by choosing Get started
Give your token a name like cert-manager
Under Permissions give read access to Zone : Zone and write access to Zone : DNS
Under Zone Resources set it to Include : All Zones
Click Continue to summary and then Create Token
Export this token and your Cloudflare email address to an environment variable on your system to be used in the following steps

export BOOTSTRAP_CLOUDFLARE_EMAIL="k8s-at-home@gmail.com"
export BOOTSTRAP_CLOUDFLARE_TOKEN="kpG6iyg3FS_du_8KRShdFuwfbwu3zMltbvmJV6cD"

🔹 GitOps with Flux

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

Verify Flux can be installed

flux check --pre
# ► checking prerequisites
# ✔ kubectl 1.21.0 >=1.18.0-0
# ✔ Kubernetes 1.20.5+k3s1 >=1.16.0-0
# ✔ prerequisites checks passed

Pre-create the flux-system namespace

kubectl 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

Export more environment variables for application configuration

# The repo you created from this template
export BOOTSTRAP_GITHUB_REPOSITORY="https://github.com/k8s-at-home/home-cluster"
# Choose one of your domains or use a made up one
export BOOTSTRAP_DOMAIN="k8s-at-home.com"

5. Create required files based on ALL exported environment variables.

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

📍 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
# customresourcedefinition.apiextensions.k8s.io/buckets.source.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/gitrepositories.source.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/helmcharts.source.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/helmreleases.helm.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/helmrepositories.source.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/kustomizations.kustomize.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/providers.notification.toolkit.fluxcd.io created
# customresourcedefinition.apiextensions.k8s.io/receivers.notification.toolkit.fluxcd.io created
# serviceaccount/helm-controller created
# serviceaccount/kustomize-controller created
# serviceaccount/notification-controller created
# serviceaccount/source-controller created
# clusterrole.rbac.authorization.k8s.io/crd-controller-flux-system created
# clusterrolebinding.rbac.authorization.k8s.io/cluster-reconciler-flux-system created
# clusterrolebinding.rbac.authorization.k8s.io/crd-controller-flux-system created
# service/notification-controller created
# service/source-controller created
# service/webhook-receiver created
# deployment.apps/helm-controller created
# deployment.apps/kustomize-controller created
# deployment.apps/notification-controller created
# deployment.apps/source-controller 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"

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

📣 Post installation

Verify Flux

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

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	v1.3.0  	False
# default        	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!

🤖 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.

Flux upgrade schedule - workflow to upgrade Flux.
Renovate schedule - workflow to annotate HelmRelease's which allows Renovate to track Helm chart versions.

Workflow Notes

Adding a new namespace

jbruns / minikube-sandbox