kubernetes

https://www.katacoda.com/courses/kubernetes
minikube version # check version 1.2.0
minikube start

   1 $ minikube version
   2 minikube version: v1.2.0
   3 $ minikube start
   4 * minikube v1.2.0 on linux (amd64)
   5 * Creating none VM (CPUs=2, Memory=2048MB, Disk=20000MB) ...
   6 * Configuring environment for Kubernetes v1.15.0 on Docker 18.09.5
   7   - kubelet.resolv-conf=/run/systemd/resolve/resolv.conf
   8 * Pulling images ...
   9 * Launching Kubernetes ...
  10 
  11 * Configuring local host environment ...
  12 * Verifying: apiserver proxy etcd scheduler controller dns
  13 * Done! kubectl is now configured to use "minikube"

cluster details and health status

   1 $ kubectl cluster-info
   2 Kubernetes master is running at https://172.17.0.30:8443
   3 KubeDNS is running at https://172.17.0.30:8443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
   4 
   5 To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

get cluster nodes

   1 $ kubectl get nodes
   2 NAME       STATUS   ROLES    AGE    VERSION
   3 minikube   Ready    master   3m1s   v1.15.0

deploy containers

# deploy container
$ kubectl create deployment first-deployment --image=katacoda/docker-http-server
deployment.apps/first-deployment created
$ # deploy container in cluster
# check pods
$ kubectl get pods
NAME                               READY   STATUS    RESTARTS   AGE
first-deployment-8cbf74484-s2fkl   1/1     Running   0          25s
# expose deployment
$ kubectl expose deployment first-deployment --port=80 --type=NodePort
service/first-deployment exposed

$ kubectl get svc first-deployment
NAME               TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
first-deployment   NodePort   10.98.246.87   <none>        80:31219/TCP   105s
# do request to port 80 in cluster ip
$ curl 10.98.246.87:80
<h1>This request was processed by host: first-deployment-8cbf74484-s2fkl</h1>

$curl host01:31219
<h1>This request was processed by host: first-deployment-8cbf74484-s2fkl</h1>

dashboard

$ minikube addons enable dashboard 
#The Kubernetes dashboard allows you to view your applications
in a UI.
* dashboard was successfully enabled
$ kubectl apply -f /opt/kubernetes-dashboard.yaml 
# only in katacoda
service/kubernetes-dashboard-katacoda created

# check progress
$ kubectl get pods -n kube-system -w  #check progress
NAME                                    READY   STATUS    RESTARTS   AGE
coredns-5c98db65d4-b2kxm                1/1     Running   0          17m
coredns-5c98db65d4-mm567                1/1     Running   1          17m
etcd-minikube                           1/1     Running   0          16m
kube-addon-manager-minikube             1/1     Running   0          16m
kube-apiserver-minikube                 1/1     Running   0          16m
kube-controller-manager-minikube        1/1     Running   0          16m
kube-proxy-pngm9                        1/1     Running   0          17m
kube-scheduler-minikube                 1/1     Running   0          16m
kubernetes-dashboard-7b8ddcb5d6-xt5nt   1/1     Running   0          76s
storage-provisioner                     1/1     Running   0          17m

^C$
# dashboard url https://2886795294-30000-kitek05.environments.katacoda.com/
# how to launch a Single Node Kubernetes cluster.