Enable Kubernetes
From Docker Preferences, enable Kubernetes.
Check to see if it is running by issuing the following command:
> kubectl get nodes
NAME STATUS ROLES AGE VERSION docker-for-desktop Ready master 5h v1.10.3
Install the Dashboard
> kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml
Verify that it is installed:
> kubectl get pods --all-namespaces -o wide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE docker compose-74649b4db6-zpb5t 1/1 Running 0 5h 10.1.0.3 docker-for-desktop docker compose-api-8477889868-jfzph 1/1 Running 0 5h 192.168.65.3 docker-for-desktop kube-system etcd-docker-for-desktop 1/1 Running 0 5h 192.168.65.3 docker-for-desktop kube-system kube-apiserver-docker-for-desktop 1/1 Running 0 5h 192.168.65.3 docker-for-desktop kube-system kube-controller-manager-docker-for-desktop 1/1 Running 0 5h 192.168.65.3 docker-for-desktop kube-system kube-dns-86f4d74b45-txr8w 3/3 Running 0 5h 10.1.0.2 docker-for-desktop kube-system kube-proxy-q5vrd 1/1 Running 0 5h 192.168.65.3 docker-for-desktop kube-system kube-scheduler-docker-for-desktop 1/1 Running 0 5h 192.168.65.3 docker-for-desktop kube-system kubernetes-XXX 1/1 Running 0 50s 10.1.0.4 docker-for-desktop
Create a dashboard admin user:
vi dashboard-adminuser.yaml
apiVersion: v1 kind: ServiceAccount metadata: name: admin-user namespace: kube-system --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: admin-user roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: cluster-admin subjects: - kind: ServiceAccount name: admin-user namespace: kube-system
> kubectl apply -f dashboard-adminuser.yaml
serviceaccount/admin-user created clusterrolebinding.rbac.authorization.k8s.io/admin-user created
Get the Token for the created user
> kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')
Name: admin-user-token-shqsn
Namespace: kube-system
Labels: <none>
Annotations: kubernetes.io/service-account.name: admin-user
kubernetes.io/service-account.uid: 8ab8e997-1069-11e9-9ec0-025000000001
Type: kubernetes.io/service-account-token
Data
====
token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi11c2VyLXRva2VuLXNocXNuIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFkbWluLXVzZXIiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiI4YWI4ZTk5Ny0xMDY5LTExZTktOWVjMC0wMjUwMDAwMDAwMDEiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWRtaW4tdXNlciJ9.MejrO_QQmPOg-ga5wXatkBBsTD5NbT0GHyIdxK5Ki3L4Yt1ZjTB8cCmhC2cN7kpus6RXN8fZpeB72UohSd1JBOJbJ9QFobSfEXXgKWD9r366hkuqP3lObTUexNDTsVlx12WUD6Vp_QAkq8ItIQ3o6xdeA2udhrAB8E55vPhK2PzyuaLHkkT-87CmG1amdn9mpZGv4FNHUvS7TYHvHs2ShisWZgLsC9hF8t_TngGWcUA5OXqH_5CzdLAYj3f2qXwXmbYiwrHT9T8PL3gchDDDuvhDxjesWqdWRjKYDU1mJ5oNskEiBQcRF0mOwl5BlZm8VwNAV1CUdKKXeSeI7_cZ6g
ca.crt: 1025 bytes
namespace: 11 bytes
Start-up Proxy
kubectl proxy
Starting to serve on 127.0.0.1:8001
Open your browser
Navigate to:
Sign in using the token previously retrieved.
Install Sample Pod
> vi nginx-example.yaml
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
name: nginx-deployment
spec:
selector:
matchLabels:
app: nginx
replicas: 2 # tells deployment to run 2 pods matching the template
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx
spec:
type: NodePort
selector:
app: nginx
ports:
- port: 80
nodePort: 31080
name: nginx
> kubectl apply -f nginx-example.yaml
Open your browser to http://localhost:31080/
More Advances Examples
Node Storage
mkdir -p ~/k8s/LOCAL_STORAGE
vi local-storage.yml
apiVersion: v1
kind: PersistentVolume
metadata:
name: local-storage
spec:
capacity:
storage: 10Gi
# volumeMode field requires BlockVolume Alpha feature gate to be enabled.
volumeMode: Filesystem
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Delete
storageClassName: local-storage
local:
path: /Users/<USER>/k8s/LOCAL_STORAGE
nodeAffinity:
required:
nodeSelectorTerms:
- matchExpressions:
- key: kubernetes.io/hostname
operator: In
values:
- docker-for-desktop
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: local-storage-claim
spec:
storageClassName: local-storage
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 3Gi
Minecraft Server with Resource Declarations
This example defines a minecraft server that uses:
- local storage
- resource management
vi minecraft.yml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: minecraft
spec:
replicas: 1
template:
metadata:
labels:
app: minecraft
spec:
containers:
- name: minecraft
image: itzg/minecraft-server
env:
- name: EULA
value: "TRUE"
- name: VERSION
value: "LATEST"
- name: OPS
value: johnmehan
resources:
requests:
memory: "1024Mi"
cpu: "1000m"
limits:
memory: "2048Mi"
cpu: "2000m"
ports:
- containerPort: 25565
volumeMounts:
- mountPath: /data
name: local-vol
subPath: minecraft/data
volumes:
- name: local-vol
persistentVolumeClaim:
claimName: local-storage-claim
---
apiVersion: v1
kind: Service
metadata:
name: minecraft
spec:
type: NodePort
selector:
app: minecraft
ports:
- port: 25565
nodePort: 32556
name: minecraft
Rest Cluster/Start Over
If you want to reset your cluster and start from scratch, you can do this through the Docker UI.
References
| Reference | URL |
|---|---|
| Docker - Deploy on Kubernetes | https://docs.docker.com/docker-for-mac/kubernetes/ |
| Kubernetes Dashboard | https://github.com/kubernetes/dashboard |
| Getting Started with Kubernetes with Docker on Mac | https://rominirani.com/tutorial-getting-started-with-kubernetes-with-docker-on-mac-7f58467203fd |