📝(tilt) add startup guide to Tilt use

This provides an "how-to" to deploy a local dev
Kubernetes environment.

docs/local_development_kube.md

@@ -0,0 +1,115 @@
+# Local development with Kubernetes
+
+We use tilt to provide a local development environment for Kubernetes. 
+Tilt is a tool that helps you develop applications for Kubernetes. 
+It watches your files for changes, rebuilds your containers, and restarts your pods. 
+It's like having a conversation with your cluster.
+
+
+## Prerequisites
+
+This guide assumes you have the following tools installed:
+
+- [Docker](https://docs.docker.com/get-docker/)
+- [Kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/)
+- [Kind](https://kind.sigs.k8s.io/docs/user/quick-start/)
+  * [mkcert](https://github.com/FiloSottile/mkcert) 
+- [ctlptl](https://github.com/tilt-dev/ctlptl)
+- [Tilt](https://docs.tilt.dev/install.html)
+  * [helm](https://helm.sh/docs/intro/install/)
+  * [helmfile](https://github.com/helmfile/helmfile)
+  * [secrets](https://github.com/jkroepke/helm-secrets/wiki/Installation)
+  * [sops](https://github.com/getsops/sops)
+
+
+### SOPS configuration
+
+**Generate a SOPS key**
+
+For this specific step you need to have the `age-keygen` tool installed.
+See https://github.com/FiloSottile/age.
+Then generate a key:
+
+```bash
+age-keygen -o my-age.key
+```
+
+**Install the SOPS key**
+
+Read the SOPS documentation on how to install the key in your environment.
+https://github.com/getsops/sops?tab=readme-ov-file#22encrypting-using-age
+
+On Ubuntu it's like:
+
+```bash
+mkdir -p ~/.config/sops/age/
+cp my-age.key ~/.config/sops/age/keys.txt
+chmod 400 ~/.config/sops/age/keys.txt
+```
+
+**Add the SOPS key to the repository**
+
+Update the [.sops.yaml](../.sops.yaml) file with the **public** key id you generated.
+
+
+### Helmfile in Docker
+
+If you use helmfile in Docker, you may need an additional configuration to make 
+it work with you age key.
+
+You need to mount `-v "${HOME}/.config/sops/age/:/helm/.config/sops/age/"`
+
+```bash
+#!/bin/sh
+
+docker run --rm --net=host \
+   -v "${HOME}/.kube:/root/.kube" \
+   -v "${HOME}/.config/helm:/root/.config/helm" \
+   -v "${HOME}/.config/sops/age/:/helm/.config/sops/age/" \
+   -v "${HOME}/.minikube:/${HOME}/.minikube" \
+   -v "${PWD}:/wd" \
+   -e KUBECONFIG=/root/.kube/config \
+   --workdir /wd ghcr.io/helmfile/helmfile:v0.150.0 helmfile "$@"
+```
+
+
+## Getting started
+
+### Create the kubernetes cluster
+
+Run the following command to create a kubernetes cluster using kind:
+
+```bash
+./bin/start-kind.sh
+```
+
+**or** run the equivalent using the makefile
+
+```bash
+make start-kind
+```
+
+### Deploy the application
+
+```bash
+tilt up -f ./bin/Tiltfile
+```
+
+**or** run the equivalent using the makefile
+
+```bash
+make tilt-up
+```
+
+That's it! You should now have a local development environment for Kubernetes.
+
+You can access the application at https://desk.127.0.0.1.nip.io
+
+## Management
+
+To manage the cluster, you can use k9s.
+
+## Next steps
+
+- Add dimail to the local development environment
+- Add a reset demo `cmd_button` to Tilt