Skaffold Example

This is a barebones example for the purposes of illustration of how we can leverage Skaffold to develop in a Kubernetes environment.

What does Skaffold do for us?

A: A lot of things - check out the docs for more info, I'm not going to dive into all of the functionality today.

Skaffold's dev workflow is what I'll be focusing on. It chains together three common things:

• A file watcher with "hot reload" functionality. When source code changes we perform:
  • Automatic docker build (and push if desired)
  • Automatic helm deploy - in our case, to a local minikube cluster

Prerequesites

• Skaffold
• Minikube
• Kubectl
• Docker
• Helm3

Quick Bootstrap

Assuming you have all prerequesites installed, go ahead and launch a minikube instance

minikube start --driver=docker --kubernetes-version=1.21.0 --memory 4196 --cpus 4 --disk-size 50Gb

Once this is done, running kubectl config use-context minikube will switch your kubectl to use the minikube context (note: kubectx is a nice tool for switching contexts!)

Because minikube has its own Docker daemon to manage its images, we need to point our local terminal to use minikube's docker daemon so we can build images locally and have them be available in the minikube environment.

Running eval $(minikube docker-env) will do just that. Now any ‘docker’ command you run in this current terminal will run against the docker inside minikube cluster. (See minikube docs)

Now, skaffold dev is the command we'll focus on. Run it and you'll notice:

1. It'll build the image specified in your repo's Dockerfile, tagging it based on what's in our skaffold.yaml
2. It'll then use the helm chart and values file specified in skaffold.yaml to deploy the image automatically to our minikube cluster.
3. It'll port-forward all traffic from 0.0.0.0:9000 -> port 8080 on the deployment we've specified
4. It'll automatically re-deploy when code changes!