How to deploy an image in Kubernetes - Raspberry Pi

Deploy an image in Kubernetes

I recommend you look at my other two repositories first Deploy Kubernetes on raspberry pi Create a custom image

Deploy an nginx image

Simple CLI command

kubectl create deployment nginx --image=nginx

Using YAML file

#nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx

Deploy using this command:

  kubectl apply -f nginx.yaml
  
  To check depplyment:
  
      kubectl get deployments

Deploy Node Port Service

Thru CLI

kubectl create service nodeport nginx --tcp=80:32000

Using YAML

#nginxservice.yaml
apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  type: NodePort
  selector:
    app: nginx
  ports:
    - protocol: TCP
      port: 80
      nodePort: 32000

Then run:

  kubectl apply -f nginxservice.yaml

Validate the service deployment

  kubectl get services
  You should see the service deployed on port 32000

Test the deployment

curl [IP address of any node (RPi)]:[Port by the Node Port]
ie curl 192.168.42.101:32000
You should see the HTML of the nginx page

If you are getting a error that cannot get the page, see below

IMPORTANT iptables issues on Pi

If you have issue with reaching between PODs run this command after boot

sudo iptables -P FORWARD ACCEPT
https://github.com/coreos/flannel/issues/799

If that didn't work after reboot, modify this file on all nodes

Edit /etc/sysctl.conf
Uncomment or add the following line: net.ipv4.ip_forward=1
Reboot

deployment.apps/nginx created

 $ kubectl create deployment nginx --image=crhostservices/armcusnginx

$ kubectl get deployments
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   0/1     1            0           16s

$ kubectl create service nodeport nginx --tcp=80:80
service/nginx created

$ kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
nginx-65f88748fd-7hb6x   1/1     Running   0          41s

$ kubectl describe service nginx
Name:                     nginx
Namespace:                default
Labels:                   app=nginx
Annotations:              <none>
Selector:                 app=nginx
Type:                     NodePort
IP:                       10.102.102.220
Port:                     80-80  80/TCP
TargetPort:               80/TCP
NodePort:                 80-80  31681/TCP
Endpoints:                10.244.2.8:80
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

Delete deployment and pods associated with it

kubectl delete deployments mynginx