seb-demo

A small project for bootstrapping a local cluster with some baseline resources for local development.

Resources:

• Crossplane documentation
• Crossplane Terraform provider
• GitHub Terraform provider
• Demo (video) - GitHub repository creation with the Cossplane Terraform provider

Prerequisites

You need to install the following tools:

• GitHub CLI
• kubectl
• kustomize
• kubectx + kubens
• kind

In WSL or linux like shell, you can run the following to install everything:

sh <(curl -L https://nixos.org/nix/install) --daemon
nix-env -iA nixpkgs.gh nixpkgs.kubectl nixpkgs.kubectx
go install sigs.k8s.io/kind@latest
go install sigs.k8s.io/kustomize/kustomize/v5@latest

Not required, but a great tool to use in OpenLens (there is a payed version of Lens as well, but that costs money). It's basically an Kubernetes IDE, which is a godsend when working with Kubernetes. Personally I installed it with Scoop, but there are other options listed here

Bootstrap Cluster

Create Cluster

First we need to create the Kind cluster:

kind create cluster

This command will create a new Kind cluster and add creds to your kubeconfig, which will make subsequent calls with kubectl use the Kind cluster. You can verify this by running kubectx in your terminal and making sure that the context you are using is called kind-kind. If you run kubens the number of namespaces in the cluster shouldn't be more than like 5. If you have openlens you can also use that while using the local cluster.

Setup ArgoCD

ArgoCD is located under k8s/argocd, and can be setup by running kubectl apply -k k8s/argocd. With lens you can use port-forwarding to access it in the browser.

Build k8s config

You can run the following commands to make sure that it all looks correct. The environmental variables and envsubst will inject secrets to github-creds.yaml without committing any real secrets to code.

export GH_TOKEN=$(gh auth token)
kustomize build --enable-helm k8s | envsubst

You can verfiy that the secrets are indeed set by running:

kustomize build --enable-helm k8s | envsubst | yq 'select(.kind == "Secret")'

Applying k8s config

You hav 2 choices here, either run kubectl as described below, or proceed by using ArgoCD and the bootstrapped applications. Do note that if you use the ArgoCD applications, the secrets will be dumy values that you will have to overwrite yourself (eg github-creds.yaml is using ${GH_TOKEN}, which in the kubectl solution can be overwritten with envsubst).

For actually applying it all you can run the command below, but do make sure first you are actually connected to the local cluster. Do note that it will take a couple of repeated invokations before it all is ready. This is because there are CRD:s that takes some time to be installed correctly. Continue running the commads a few times over a minute or so and it should all be working:

kustomize build --enable-helm k8s/crossplane-system | envsubst | kubectl apply -f -