Michael Hausenblas mhausenblas

Developing apps on Kubernetes

2018-04-04 at CNCF Paris

How do you develop a Kubernetes app, that is, how do you write and test an app that is supposed to run on Kubernetes? In this talk Michael will discuss the challenges as well as review potential tools (incl. Telepresence, ksync, and kubed-sh) you want to be aware of to successfully write Kubernetes apps.

The demo app used throughout here is kubernauts/dok-example-us.

Using ksync with Minikube
- Preparation

Docs and config

What was that field in the manifest again?

$ kubectl explain statefulset.spec.template.spec

List contexts:

Kubernetes The Hard Way Notes

Reference: kelseyhightower/kubernetes-the-hard-way

Step 1: Cloud Infrastructure Provisioning - Google Cloud Platform

Reference: step 1

Verification:

	apiVersion: v1
	kind: Service
	metadata:
	name: nginx
	labels:
	app: nginx
	spec:
	ports:
	- port: 80
	name: web

	FROM gcc:7
	COPY spectre.c /usr/src/
	WORKDIR /usr/src
	RUN gcc -std=c99 -O0 spectre.c -o spectre
	CMD ["./spectre"]

	#!/usr/bin/env bash

	minikube start \
	--cpus=3 \
	--memory=7000 \
	--kubernetes-version=v1.7.4 \
	--extra-config=apiserver.GenericServerRunOptions.AdmissionControl=NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,ResourceQuota,DefaultTolerationSeconds,PodSecurityPolicy

	apiVersion: v1
	kind: Pod
	metadata:
	name: jump
	spec:
	containers:
	- name: busybox
	image: busybox
	command:
	- sleep

	var (
	probetests = []struct {
	launchfunc func(string) error
	scheme string
	port string
	version string
	secure bool
	}{
	{util.Etcd2Up, "http", "2379", "2", false},
	{util.Etcd3Up, "http", "2379", "3", false},

	package main

	import (
	"flag"
	"fmt"

	"github.com/chzyer/readline"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/pkg/api/v1"
	"k8s.io/client-go/tools/clientcmd"

	apiVersion: v1
	kind: ReplicationController
	metadata:
	name: sise
	spec:
	replicas: 1
	selector:
	app: sise
	template:
	metadata: