Encode into base 64

echo -n 'admin' | base64

echo -n 'password' | base64

kubectl apply commands in order

kubectl apply -f mongo.secret.yaml

kubectl apply -f mongo.yaml

kubectl apply -f mongo.configmap.yaml

kubectl apply -f mongoExpress.yaml

kubectl get commands

kubectl get pods

kubectl get secrets

kubectl get configmaps

kubectl get all

kubectl get pod -o wide

kubectl get pod --watch

Assign external IP to service

minikube service mongo-express-service

kubectl delete commands

kubectl delete -f mongo.secret.yaml

kubectl delete -f mongo.yaml

kubectl delete -f mongo.configmap.yaml

kubectl delete -f mongoExpress.yaml

kubernetes namespaces

kubectl apply -f <filename> -n <namespace>

or

kubectl create namespace <namespace>

and change the default namespace by using kubectx and kubens, select namespace by :

kubens <namespace>

or

change namespace in the yaml file

metadata:
  name: mongo-express
  namespace: <namespace>

kubernetes ingress

start ingress controller minikupe addon

minikube addons enable ingress

kubectl get pods -n kube-system

you can see the ingress controller running, now apply the ingress rules
make a yaml file to apply, you can use namespace or directly apply to the default namespace, both cases are shown in ingress.yaml file

kubectl apply -f ingress.yaml

kubectl get ingress

now add host to link the ingress to the service

sudo gedit /etc/hosts

add the following line to the file

<port of service> <host name>

now you can access the service using the host name

Also, this ingress controller has a default backend, which is a service that handles all URL paths and hosts the ingress controller doesn't understand. Create a default backend service by:

kubectl apply -f default-backend.yaml

Which you can check by going to the host name you have given in the browser, you will see the default backend service running or by command:

kubectl describe ingress <ingress name> -n <namespace>

multiple path for same host

you can use the same host name for multiple paths, for example, you can use the same host name for both mongo-express and mongo services, for that you have to use the same ingress name for both services, and add the following lines to the ingress.yaml file

spec:
  rules:
    - host: mongo-express.info
      http:
        paths:
          - path: /
            backend:
              serviceName: mongo-express-service
              servicePort: 8081
          - path: /mongo
            backend:
              serviceName: mongo-service
              servicePort: 27017

now you can access the mongo service by using the host name and path name, for example, mongo-express.info/mongo

multiple host names for same path

you can use the same path for multiple host names, for example, you can use the same path for both mongo-express and mongo services, for that you have to use the same ingress name for both services, and add the following lines to the ingress.yaml file

spec:
  rules:
    - host: mongo-express.info
      http:
        paths:
          - path: /
            backend:
              serviceName: mongo-express-service
              servicePort: 8081
    - host: mongo.info
      http:
        paths:
          - path: /
            backend:
              serviceName: mongo-service
              servicePort: 27017

now you can access the mongo service by using the host name and path name, for example, mongo-express.info/ and mongo.info/

configure ingress to use TLS

create a self-signed certificate

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt

create a secret using the certificate

kubectl create secret tls tls-secret --cert=tls.crt --key=tls.key

add the following lines to the ingress.yaml file

spec:
  tls:
    - hosts:
        - mongo-express.info
      secretName: tls-secret
  rules:
    - host: mongo-express.info
      http:
        paths:
          - path: /
            backend:
              serviceName: mongo-express-service
              servicePort: 8081

now you can access the mongo service by using the host name and path name, for example, mongo-express.info/

or create a yaml file for secret

apiVersion: v1
kind: Secret
metadata:
  name: tls-secret
  namespace: default
data:
  tls.crt: <base64 encoded crt file>
  tls.key: <base64 encoded key file>
type: kubernetes.io/tls

and apply it by

kubectl apply -f <filename>