Skaffold hands on

This is a sample joke-service showing how Skaffold can ease development

Prerequisites

• JDK 17
• Minikube
• Skaffold

Service short description

Joke-service is an ordinary Kotlin + Spring Boot + Maven web service exposing single endpoint for fetching random jokes. Service can fetch jokes from 2 different sources (see joke-api.http):

• internal Postgresql database
• external Chuck Norris api

Each valid request is also logged to database

Project structure

• src: contains, non surprisingly, joke-service and tests source code
• k8s: contains k8s manifests: base folder is for the joke-serivce itself and dev/deps folder is for dev environment (postgresql.yaml for Postgresql database and wiremock.yaml as an external api Wiremock)
• skaffold.yaml: Skaffold config file

How to use Skaffold

NOTE: Throughout this section skaffold.yaml config file will be referenced as simply "config"

Start your Minikube before running Skaffold commands, for example, like this:

minikube start --memory=10g --cpus=6 --disk-size='120000mb' --addons=metrics-server

dev mode

All you need to do to build an image for joke-service and deploy it as well as dev environment to Minikube in dev mode is to run:

skaffold dev --port-forward

This command will do following:

• build an image for joke-service according to build config section
• deploy k8s resources referenced in manifests.kustomize.paths config section to Minikube (joke-service itself and dev environment)
• forward k8s resources' ports to your localhost thanks to --port-forward option
• continuously rebuild and redeploy resources if some changes are encountered in k8s manifests or in files referenced in build.artifacts.custom.dependencies.paths config section

Now joke-service is up and running, you can access it via localhost, play with it, try to change some files and see what happens

dev environment only mode

If you want to deploy to Minikube only dev environment without building and deploying the joke-service then run:

skaffold dev --port-forward -p depsOnly

This command will apply depsOnly profile from config, see profiles section. Differences with previous command:

• Skaffold will not build image for joke-service
• only k8s manifests describing dev environment resources will be picked up

Now you can launch joke-service as you wish, for example with magic green run or debug button in IntelliJ, just don't forget to activate dev profile

debug mode

In order to debug run:

skaffold debug --port-forward

What this command will do differently compared to dev command:

• expose additional debug port (5005 by default), which will be also forwarded to your localhost
• Skaffold will not be tracking changes in k8s manifests and referenced files

Now you can attach your IDE to the debug port, and it will start hitting breakpoints! In order to do so in IntelliJ simply add and launch default Remote JVM Debug configuration