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Minikube : Basic Usage
2022/07/20
 
This is the basic operation on Single Node Kubernetes Cluster on Minikube.
[1] Create or Delete Pods.
# run [test-nginx] pods

[cent@dlp ~]$
kubectl create deployment test-nginx --image=nginx

deployment.apps/test-nginx created
[cent@dlp ~]$
kubectl get pods

NAME                          READY   STATUS    RESTARTS   AGE
test-nginx-7f4c594655-c5jzp   1/1     Running   0          16s

# show environment variables for [test-nginx] pod

[cent@dlp ~]$
kubectl exec test-nginx-7f4c594655-c5jzp -- env

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=test-nginx-7f4c594655-c5jzp
KUBERNETES_PORT=tcp://10.96.0.1:443
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
KUBERNETES_PORT_443_TCP_PROTO=tcp
KUBERNETES_PORT_443_TCP_PORT=443
KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
KUBERNETES_SERVICE_HOST=10.96.0.1
KUBERNETES_SERVICE_PORT=443
KUBERNETES_SERVICE_PORT_HTTPS=443
NGINX_VERSION=1.23.1
NJS_VERSION=0.7.6
PKG_RELEASE=1~bullseye
HOME=/root

# shell access to [test-nginx] pod

[cent@dlp ~]$
kubectl exec -it test-nginx-7f4c594655-c5jzp -- bash
root@test-nginx-7f4c594655-c5jzp:/#
hostname

test-nginx-7f4c594655-c5jzp
root@test-nginx-7f4c594655-c5jzp:/#
exit
# show logs of [test-nginx] pod

[cent@dlp ~]$
kubectl logs test-nginx-7f4c594655-c5jzp

/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: info: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
2022/07/20 01:01:48 [notice] 1#1: using the "epoll" event method
2022/07/20 01:01:48 [notice] 1#1: nginx/1.23.1
2022/07/20 01:01:48 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6)
2022/07/20 01:01:48 [notice] 1#1: OS: Linux 5.10.57
2022/07/20 01:01:48 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2022/07/20 01:01:48 [notice] 1#1: start worker processes
2022/07/20 01:01:48 [notice] 1#1: start worker process 32
2022/07/20 01:01:48 [notice] 1#1: start worker process 33

# scale out pods

[cent@dlp ~]$
kubectl scale deployment test-nginx --replicas=3

deployment.apps/test-nginx scaled
[cent@dlp ~]$
kubectl get pods

NAME                          READY   STATUS    RESTARTS   AGE
test-nginx-7f4c594655-c5jzp   1/1     Running   0          3m42s
test-nginx-7f4c594655-h8hdh   1/1     Running   0          9s
test-nginx-7f4c594655-r7mkl   1/1     Running   0          9s

# set service

[cent@dlp ~]$
kubectl expose deployment test-nginx --type="NodePort" --port 80

service/test-nginx exposed
[cent@dlp ~]$
kubectl get services test-nginx

NAME         TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
test-nginx   NodePort   10.101.185.10   <none>        80:32225/TCP   4s

[cent@dlp ~]$
minikube service test-nginx --url

http://192.168.39.57:32225
[cent@dlp ~]$
curl http://192.168.39.57:32225

<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
.....
.....
<p><em>Thank you for using nginx.</em></p>
</body>
</html>

# delete service

[cent@dlp ~]$
kubectl delete services test-nginx

service "test-nginx" deleted
# delete pods

[cent@dlp ~]$
kubectl delete deployment test-nginx

deployment.extensions "test-nginx" deleted
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