Kubernetes Let’s Encrypt wildcard

1-Installing Cert-Manager

There's 2 ways to install cert-manager, by kubectl from the cert-manager source and the other one is by using helm. Use only one from the 2 options.

Installing Cert-Manager by kubectl

kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.14.2/cert-manager.yaml

To check the latest cert-manager versions you can visit: Cert-manager kubectl Installation guide

Installing Cert-Manager by helm charts

helm repo add jetstack https://charts.jetstack.io
helm repo update
helm install cert-manager jetstack/cert-manager --namespace cert-manager --create-namespace --set installCRDs=true

2-Installing Nginx ingress controller

helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm update
helm install ingress-controller ingress-nginx/ingress-nginx

Or you can check this link for installation from kubectl: Nginx Ingress Controller Installation Guide

3-Configure The Let's Encrypt Certificate Issuer

To finish this you need to create a file for ex. letsencrypt-production.yaml and put the below inside it:

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: letsencrypt-production
spec:
  acme:
    server: https://acme-v02.api.letsencrypt.org/directory
    email: example@domain.com
    privateKeySecretRef:
      name: letsencrypt-production
    solvers:
      - http01:
          ingress:
            class: nginx

Then execute the following command:

kubectl create -f letsencrypt-production.yaml

And finally you need to create a file for ex. website.yaml and put the below inside it:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: mywebsite-ingress
  namespace: default
  uid: 9d760e20-99e3-4db1-98a3-c32f49450bc1
  resourceVersion: '12967504259'
  generation: 1
  creationTimestamp: '2024-02-22T10:33:48Z'
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-production
    kubernetes.io/ingress.class: nginx
  managedFields:
    - manager: kubectl-client-side-apply
      operation: Update
      apiVersion: networking.k8s.io/v1
      time: '2024-02-22T10:33:48Z'
      fieldsType: FieldsV1
      fieldsV1:
        f:metadata:
          f:annotations:
            .: {}
            f:cert-manager.io/cluster-issuer: {}
            f:kubectl.kubernetes.io/last-applied-configuration: {}
            f:kubernetes.io/ingress.class: {}
        f:spec:
          f:rules: {}
          f:tls: {}
    - manager: nginx-ingress-controller
      operation: Update
      apiVersion: networking.k8s.io/v1
      time: '2024-02-22T10:34:16Z'
      fieldsType: FieldsV1
      fieldsV1:
        f:status:
          f:loadBalancer:
            f:ingress: {}
      subresource: status
  selfLink: /apis/networking.k8s.io/v1/namespaces/default/ingresses/mywebsite-ingress
status:
  loadBalancer:
    ingress:
      - ip: 88.88.88.88 #Your ingress-nginx public IP
spec:
  tls:
    - hosts:
        - example.website.com
      secretName: letsencrypt-production
  rules:
    - host: example.website.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: wordpress #Or the name of the service that you need to put
                port:
                  number: 80