As an extra, here is a recipe to run a service using K8s’s minikube:
name="webthing-go"
url="https://raw.githubusercontent.com/rzr/webthing-go/master/extra/tools/kube/$name.yml"
kubectl=kubectl
kubectl version || kubectl="sudo kubectl" # Maybe you'd better check your env
minikube version
#| minikube version: v1.3.0
minikube start || minikube logs --alsologtostderr
$kubectl version
#| Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.1", ...
#| Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.2", ...
$kubectl apply -f "${url}"
#| deployment.extensions/webthing-go created
#| service/webthing-go created
$kubectl get services
#| webthing-go NodePort 10.100.249.206 <none> 8888:30080/TCP 4s
minikube service ${name} --url
#| http://192.168.99.102:30080
time minikube service ${name}
#| 🎉 Opening kubernetes service default/webthing-go in default browser...
The process can be automatically move between cluster’s nodes:
project="webthing-go"
kubectl=kubectl
command="go run example/simplest-thing.go"
kubectl get nodes
#| NAME STATUS ROLES AGE VERSION
#| slave01 Ready <none> 94m v1.15.2
#| master Ready master 99m v1.15.2
kubectl describe nodes
kubectl get services $project
#| webthing-go NodePort 10.104.44.241 <none> 8888:30080/TCP 32s
pod=$($kubectl get all --all-namespaces \
| grep -o "pod/${project}.*" | cut -d/ -f2 | awk '{ print $1}' \
|| echo failure) && echo pod="$pod"
kubectl describe pods "$pod"
ip=$($kubectl describe pod "$pod" | grep 'IP:' | awk '{ print $2 }') && echo "ip=${ip}"
curl -i http://$ip:8888/ | grep "HTTP/1.1 200 OK"
#| webthing-go-58d7cc6657 1 1 1 34m
# Move process to slave host
kubectl drain $HOSTNAME --ignore-daemonsets --delete-local-data
kubectl cordon $HOSTNAME
kubectl uncordon $hostname
$kubectl get all --all-namespaces | grep $project
ps auxf | grep -5 "$command" | grep -v grep # on slave
#| go run ...
# Moving back to master host
kubectl drain $hostname --ignore-daemonsets --delete-local-data
kubectl cordon $hostname
kubectl uncordon $HOSTNAME
$kubectl get all --all-namespaces | grep $project
ps auxf | grep -- "$command" | grep -v grep # on master
#| root 1561 0.2 0.2 3474520 48392 ? Ssl 16:08 0:26 /usr/bin/containerd
#| root 11758 0.0 0.0 107344 5428 ? Sl 19:33 0:00 \_ containerd-shim -namespace moby ...
#| root 11779 0.0 0.0 5620 2320 ? Ss 19:33 0:00 | \_ /usr/bin/make start
#| root 11798 0.1 0.1 1295752 19404 ? Sl 19:33 0:00 | \_ go run example/simplest-thing.go
#| root 11924 0.0 0.0 477272 5696 ? Sl 19:33 0:00 | \_ /tmp/go-build000000403/b001/exe/simplest-thing