Kubernetes Hello Minikube Fedora 27

This is a quick Fedora Linux specific version of the upstream Hello Minikube guide. It uses Golang as the hello world application and tries to call out a few useful things along the way.

This is a follow up to: Kubernetes Hello Minikube Fedora 25

Dependencies

You’ll need golang, kvm and libvirt along with proper group membership:

sudo dnf install golang libvirt-daemon-kvm
sudo usermod -a -G libvirt $(whoami)
newgrp libvirt

Install minikube itself

curl -Lo minikube \
  https://github.com/kubernetes/minikube/releases/download/v0.25.2/minikube-linux-amd64 \
  && chmod +x minikube \
  && sudo mv minikube /usr/local/bin/

Install kubectl

curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.9.6/bin/linux/amd64/kubectl \
  && chmod +x kubectl \
  && sudo mv kubectl /usr/local/bin/

Install docker-machine-driver-kvm2

curl -LO https://github.com/kubernetes/minikube/releases/download/v0.25.2/docker-machine-driver-kvm2 \
  && chmod +x docker-machine-driver-kvm2 \
  && sudo mv docker-machine-driver-kvm2 /usr/local/bin

Reference: https://github.com/kubernetes/minikube/blob/master/docs/drivers.md#kvm2-driver

Create a cluster

minikube start --vm-driver=kvm2

View cluster config and info

kubectl config view
kubectl cluster-info
kubectl get pods || echo "fail"

View the vm minikube created

sudo virsh list --all
sudo virsh dumpxml minikube

View the files minikube wrote

tree ~/.minikube/

Run an upstream provided test container

kubectl run hello-minikube --image=gcr.io/google_containers/echoserver:1.4 --port=8080
kubectl expose deployment hello-minikube --type=NodePort
kubectl get pod
curl $(minikube service hello-minikube --url)
kubectl delete deployment hello-minikube
kubectl get pod

Prepare to build and deploy a local container

eval $(minikube docker-env)

After running this command docker will talk to the docker daemon inside the Minikube vm. Failing to run this command will result in Kubernetes being unable to fetch the container: ErrImagePull. See the end of this document on how to “undo” this.

Create a hello app in Golang

mkdir hello && cd hello

Then create main.go with the following contents:

package main

import (
	"fmt"
	"log"
	"net/http"
)

func indexHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello world")
}

func main() {
	http.HandleFunc("/", indexHandler)
	log.Fatal(http.ListenAndServe(":8080", nil))
}

Compile it and verify it has no dependencies

CGO_ENABLED=0 go build
ldd hello

Create a docker container

Create a Dockerfile with the following contents:

FROM scratch
EXPOSE 8080
COPY ./hello /hello
CMD ["/hello"]

Build and test the container

docker build -t hello-golang:v1 .
docker run --rm hello-golang:v1

Deploy the container to kubernetes

kubectl run hello-golang --image=hello-golang:v1 --port=8080
kubectl get deployments
kubectl get pods
kubectl get events
kubectl config view

Create a service and test it

kubectl expose deployment hello-golang --type=LoadBalancer
kubectl get services
minikube service hello-golang

Update the service and test it

vim main.go
CGO_ENABLED=0 go build
docker build -t hello-golang:v2 .
kubectl set image deployment/hello-golang hello-golang=hello-golang:v2
minikube service hello-golang

Delete the service

kubectl delete service hello-golang
kubectl delete deployment hello-golang

Stop minikube (the vm)

minikube stop

Stop directing docker at the vm

eval $(minikube docker-env -u)

Delete everything if desired

If you want to remove everything as though never started, you’d do something like this:

sudo virsh undefine minikube
rm -rf ~/.minikube
rm -rf ~/.kube

If you want to remove the dependencies as well:

sudo rm /usr/local/bin/{minikube,kubectl,docker-machine-driver-kvm2}