Kubernetes/minikube

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Minikube features v1.2.0

  • LoadBalancer - using minikube tunnel
  • Multi-cluster - using minikube start -p <name>
  • NodePorts - using minikube service
  • Persistent Volumes
  • Ingress
  • RBAC
  • Dashboard - minikube dashboard
  • Container runtimes - start --container-runtime
  • Configure apiserver and kubelet options via command-line flags

Install on Linux

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 && sudo install minikube-linux-amd64 /usr/local/bin/minikube
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 39.8M  100 39.8M    0     0   160k      0  0:04:14  0:04:14 --:--:--  174k

Start on Windows

<syntaxhighlightjs lang="powershell"> choco install minikube kubernetes-cli minikube start --vm-driver hyperv --hyperv-virtual-switch k8s-node-1 --profile k8s-node-1

  1. --hyperv-virtual-switch :- need to exist

</syntaxhighlightjs>

Start

Example of start sequence 

minikube start 
😄  minikube v1.2.0 on linux (amd64)
🔥  Creating virtualbox VM (CPUs=2, Memory=2048MB, Disk=20000MB) ...
🐳  Configuring environment for Kubernetes v1.15.0 on Docker 18.09.6
E0728 00:14:31.657125   26453 start.go:403] Error caching images:  Caching images for kubeadm: caching images: caching image /home/user1/.minikube/cache/images/k8s.gcr.io/k8s-dns-kube-dns-amd64_1.14.13: stream error: stream ID 25; INTERNAL_ERROR
❌  Unable to load cached images: loading cached images: loading image /home/pipaw/.minikube/cache/images/k8s.gcr.io/k8s-dns-sidecar-amd64_1.14.13: stat /home/user1/.minikube/cache/images/k8s.gcr.io/k8s-dns-sidecar-amd64_1.14.13: no such file or directory
💾  Downloading kubeadm v1.15.0
💾  Downloading kubelet v1.15.0
🚜  Pulling images ...
🚀  Launching Kubernetes ... 
⌛  Verifying: apiserver proxy etcd scheduler controller dns
🏄  Done! kubectl is now configured to use "minikube"

$ minikube status
host: Running
kubelet: Running
apiserver: Running
kubectl: Correctly Configured: pointing to minikube-vm at 192.168.99.101

$ kubectl get nodes -o wide
NAME       STATUS   ROLES    AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE              KERNEL-VERSION   CONTAINER-RUNTIME
minikube   Ready    master   8h    v1.15.0   10.0.2.15     <none>        Buildroot 2018.05.3   4.15.0           docker://18.9.6

$ kubectl get all -o wide --all-namespaces
NAMESPACE     NAME                                   READY   STATUS    RESTARTS   AGE   IP           NODE       NOMINATED NODE   READINESS GATES
kube-system   pod/coredns-5c98db65d4-d688k           1/1     Running   0          8h    172.17.0.2   minikube   <none>           <none>
kube-system   pod/coredns-5c98db65d4-xdq6d           1/1     Running   0          8h    172.17.0.3   minikube   <none>           <none>
kube-system   pod/etcd-minikube                      1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>
kube-system   pod/kube-addon-manager-minikube        1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>
kube-system   pod/kube-apiserver-minikube            1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>
kube-system   pod/kube-controller-manager-minikube   1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>
kube-system   pod/kube-proxy-j5f2h                   1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>
kube-system   pod/kube-scheduler-minikube            1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>
kube-system   pod/storage-provisioner                1/1     Running   0          8h    10.0.2.15    minikube   <none>           <none>

NAMESPACE     NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE   SELECTOR
default       service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP                  8h    <none>
kube-system   service/kube-dns     ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   8h    k8s-app=kube-dns

NAMESPACE     NAME                        DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                 AGE   CONTAINERS   IMAGES                          SELECTOR
kube-system   daemonset.apps/kube-proxy   1         1         1       1            1           beta.kubernetes.io/os=linux   8h    kube-proxy   k8s.gcr.io/kube-proxy:v1.15.0   k8s-app=kube-proxy

NAMESPACE     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                     SELECTOR
kube-system   deployment.apps/coredns   2/2     2            2           8h    coredns      k8s.gcr.io/coredns:1.3.1   k8s-app=kube-dns

NAMESPACE     NAME                                 DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                     SELECTOR
kube-system   replicaset.apps/coredns-5c98db65d4   2         2         2       8h    coredns      k8s.gcr.io/coredns:1.3.1   k8s-app=kube-dns,pod-template-hash=5c98db65d4

Usage

time minikube start                              #start a cluster by running
# Start another local clusters named: --profile can be abbreviated with -p, default is 'minikube'
time minikube start --kubernetes-version v1.13.7 --profile k8s-v1.13.7-aws #AWS versions 1.13.7,1.12.6
time minikube start --kubernetes-version v1.15.0 --profile k8s-v1.15.0


Get port exposed to host via Virtualbox used by minikube to interact with a cluster 

$ sudo ss -ltpn
State  Recv-Q  Send-Q    Local Address:Port    Peer Address:Port                                               
LISTEN 0       128       127.0.0.53%lo:53           0.0.0.0:*      users:(("systemd-resolve",pid=1009,fd=13))  
LISTEN 0       10            127.0.0.1:45111 #<--   0.0.0.0:*      users:(("VBoxHeadless",pid=26918,fd=21))    
LISTEN 0       5             127.0.0.1:631          0.0.0.0:*      users:(("cupsd",pid=27629,fd=7))            
LISTEN 0       5                 [::1]:631             [::]:*      users:(("cupsd",pid=27629,fd=6))

$ vboxmanage showvminfo k8s-v1.15.0 | 'grep port ='                            vv
NIC 1 Rule(0):   name = ssh, protocol = tcp, host ip = 127.0.0.1, host port = 45111, guest ip = , guest port = 22
                                                                               ^^


Access to minikube VM using ssh
minikube ssh cat /etc/*rel* 
$ minikube ssh 
                         _             _            
            _         _ ( )           ( )           
  ___ ___  (_)  ___  (_)| |/')  _   _ | |_      __  
/' _ ` _ `\| |/' _ `\| || , <  ( ) ( )| '_`\  /'__`\
| ( ) ( ) || || ( ) || || |\`\ | (_) || |_) )(  ___/
(_) (_) (_)(_)(_) (_)(_)(_) (_)`\___/'(_,__/'`\____)

$
 
cat /etc/*rel*
NAME=Buildroot
VERSION=2018.05.3
ID=buildroot
VERSION_ID=2018.05.3
PRETTY_NAME="Buildroot 2018.05.3"
NAME=Buildroot
VERSION=2018.05.3
ID=buildroot
VERSION_ID=2018.05.3
PRETTY_NAME="Buildroot 2018.05.3"


#access Kubernetes Dashboard within Minikube
minikube dashboard
🤔  Verifying dashboard health ...
🚀  Launching proxy ...
🤔  Verifying proxy health ...
🎉  Opening http://127.0.0.1:44835/api/v1/namespaces/kube-system/services/http:kubernetes-dashboard:/proxy/ in your default browser...

#Use kubectl to interact with the local cluster
kubectl run --generator=run-pod/v1         hello-minikube --image=k8s.gcr.io/echoserver:1.4 --port=8080 #correct
kubectl run --generator=deployment/apps.v1 hello-minikube --image=k8s.gcr.io/echoserver:1.4 --port=8080 #deprecated
kubectl run       ^^default^^              hello-minikube --image=k8s.gcr.io/echoserver:1.4 --port=8080 #deprecated

#Expose a service as a NodePort
kubectl expose pod        hello-minikube --type=NodePort
kubectl expose deployment hello-minikube --type=NodePort #when pod was created via deployment deprecated option

#Determine the NodePort of the service
kubectl get service <hello-minikube> --output='jsonpath="{.spec.ports[0].nodePort}"'

#curl this endpoint
minikube ssh
curl -s -H 'Cache-Control: no-cache' http://<svc-cluster-ip>:8080 #note 'watch won't work as curl or service proxy 

#minikube makes it easy to open this exposed endpoint in your browser
minikube service hello-minikube

minikube stop   #stop your local cluster
minikube delete #delete your local cluster


Working with profiles 

$ ls -1 ~/.minikube/profiles/ #list all profiles
aws-v1.13.7-cluster
minikube             #default profile

#Minikube show current profile
$ minikube profile
aws-v1.13.7-cluster
$ cat ~/.minikube/config/config.json | jq -r .profile #alternative option

#Kubectl  show current context
$ kubectl config current-context
$ kubectl config get-contexts   #get-clusters
CURRENT   NAME                  CLUSTER               AUTHINFO              NAMESPACE
*         aws-v1.13.7-cluster   aws-v1.13.7-cluster   aws-v1.13.7-cluster   
          minikube              minikube              minikube


Switching the Minikube profile does automatically switch the k8s context, and vice versa (v1.2.0 - 2019-06-24) 

#Switch minikube profile
$ minikube profile minikube #switch to profile: minikube
✅  minikube profile was successfully set to minikube

#Switch kubectl context
$ kubectl config set-context minikube
Context "minikube" modified.

Clean up if needed 

minikube delete -p <profile>
kubectl config delete-context <context-name>
kubectl config delete-context <delete-cluster>


Example of ~/.minikube/profiles/<minikube-profile>/config.json
jq .MachineConfig config.json jq .KubernetesConfig config.json 
{
  "KubernetesVersion": "v1.13.7",
  "NodeIP": "192.168.99.102",
  "NodePort": 8443,
  "NodeName": "minikube",
  "APIServerName": "minikubeCA",
  "APIServerNames": null,
  "APIServerIPs": null,
  "DNSDomain": "cluster.local",
  "ContainerRuntime": "docker",
  "CRISocket": "",
  "NetworkPlugin": "",
  "FeatureGates": "",
  "ServiceCIDR": "10.96.0.0/12",
  "ImageRepository": "",
  "ExtraOptions": null,
  "ShouldLoadCachedImages": true,
  "EnableDefaultCNI": false
}
 
{
  "KeepContext": false,
  "MinikubeISO": "https://storage.googleapis.com/minikube/iso/minikube-v1.2.0.iso",
  "Memory": 2048,
  "CPUs": 2,
  "DiskSize": 20000,
  "VMDriver": "virtualbox",
  "ContainerRuntime": "docker",
  "HyperkitVpnKitSock": "",
  "HyperkitVSockPorts": [],
  "XhyveDiskDriver": "ahci-hd",
  "DockerEnv": null,
  "InsecureRegistry": null,
  "RegistryMirror": null,
  "HostOnlyCIDR": "192.168.99.1/24",
  "HypervVirtualSwitch": "",
  "KvmNetwork": "default",
  "DockerOpt": null,
  "DisableDriverMounts": false,
  "NFSShare": [],
  "NFSSharesRoot": "/nfsshares",
  "UUID": "",
  "GPU": false,
  "Hidden": false,
  "NoVTXCheck": false
}

Addons

minikube addons enable heapster #get some insight into CPU

References

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