An NGINX Ingress is an API object that provides Layer 7 load balancing to manage external access to Services in a Kubernetes cluster. Container Service for Kubernetes (ACK) allows you to use the advanced features of NGINX Ingresses to configure specific URLs to allow external access, set rewrite rules, configure HTTPS, and implement canary releases. This topic describes how to configure secure data transmission, set mutual TLS authentication, use regular expressions to specify domain names, use wildcard domain names, apply for free TLS certificates, and customize other related features.

Prerequisites

NGINX configuration

The methods that are used to configure the NGINX Ingress controller in ACK are fully compatible with the open source version of the component. For more information about the configuration methods, see NGINX Configuration.

The following configuration methods are supported:
  • Annotation: You can modify annotations in the YAML template of each NGINX Ingress. The annotations take effect on individual NGINX Ingresses. For more information, see Annotations.
  • ConfigMap: You can modify the kube-system/nginx-configuration ConfigMap to set a global configuration for all NGINX Ingresses. For more information, see ConfigMaps.
  • Custom NGINX template: You can customize the NGINX template of an NGINX Ingress controller if the preceding methods cannot meet your requirements. For more information, see Custom NGINX template.

Configure routing rules to redirect traffic from specific URLs

After you configure the NGINX Ingress controller, the NGINX Ingress controller redirects requests from specific URLs to the backend. For example, the NGINX Ingress controller redirects requests from /service1/api to /service1/api/ of backend pods. If the URL of your backend service is /api, a 404 status code is returned because the URL of the backend service is different from the requested URL. In this case, you can configure rewrite-target to rewrite the requested URL to the URL that you want to use.

  1. Create an NGINX Ingress by using the following template:
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1beta1
    kind: Ingress
    metadata:
      name: foo.bar.com
      namespace: default
      annotations:
        # URL redirection. 
        nginx.ingress.kubernetes.io/rewrite-target: /$2
    spec:
      rules:
      - host: foo.bar.com
        http:
          paths:
        # If the version of the Ingress controller is 0.22.0 or later, you must use regular expressions to specify URLs and use the regular expressions with capture groups in rewrite-target. 
          - path: /svc(/|$)(.*)
            backend:
              serviceName: web1-service
              servicePort: 80
    EOF
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: foo.bar.com
      namespace: default
      annotations:
        # URL redirection. 
        nginx.ingress.kubernetes.io/rewrite-target: /$2
    spec:
      rules:
      - host: foo.bar.com
        http:
          paths:
        # If the version of the Ingress controller is 0.22.0 or later, you must use regular expressions to specify URLs and use the regular expressions with capture groups in rewrite-target. 
          - path: /svc(/|$)(.*)
            backend:
              service: 
                name: web1-service
                port: 
                  number: 80
            pathType: ImplementationSpecific
    EOF

  2. Run the following command to access the NGINX application.
    Replace IP_ADDRESS with the IP address of the created Ingress. You can obtain the IP address by running the kubectl get ing command.
    curl -k -H "Host: foo.bar.com"  http://<IP_ADDRESS>/svc/foo

    Expected output:

    web1: /foo

Configure rewrite rules

The nginx.ingress.kubernetes.io/rewrite-target annotation can be used to configure basic rewrite rules. To configure advanced rewrite rules, use the following annotations:

  • nginx.ingress.kubernetes.io/server-snippet: This annotation adds custom configurations to the Server configuration block.
  • nginx.ingress.kubernetes.io/configuration-snippet: This annotation adds custom configurations to the Location configuration block.

Example:

annotations:
     nginx.ingress.kubernetes.io/server-snippet: |
         rewrite ^/v4/(.*)/card/query http://foo.bar.com/v5/#!/card/query permanent;
     nginx.ingress.kubernetes.io/configuration-snippet: |
         rewrite ^/v6/(.*)/card/query http://foo.bar.com/v7/#!/card/query permanent;

The following example shows the configuration of the nginx.conf file:

## start server foo.bar.com
    server {
        server_name foo.bar.com ;
        listen 80;
        listen [::]:80;
        set $proxy_upstream_name "-";
    ### Configuration of server-snippet. 
        rewrite ^/v4/(.*)/card/query http://foo.bar.com/v5/#!/card/query permanent;
        ...
    ### Configuration of configuration-snippet. 
      rewrite ^/v6/(.*)/card/query http://foo.bar.com/v7/#!/card/query permanent;
      ...
    }
    ## end server foo.bar.com

In addition, snippet also supports some global configurations. For more information, see server-snippet.

For more information about how to use rewrite rules, see Description of rewrite rules in the NGINX official document.

Configure a TLS certificate for Ingress rules

You can configure NGINX Ingress configurations to specify a TLS certificate for a website.

  1. Prepare your certificate.
    Note The domain name associated with the certificate must be the same as the host that you specified. Otherwise, the NGINX Ingress controller cannot load the TLS certificate.
    1. Run the following command to generate a certificate file named tls.crt and a private key file named tls.key:
      openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=foo.bar.com/O=foo.bar.com"
    2. Run the following command to create a Kubernetes Secret.
      Use the certificate and private key to create a Secret named tls-test-ingress. The Secret is referenced when you create an Ingress.
      kubectl create secret tls tls-test-ingress --key tls.key --cert tls.crt
  2. Run the following command to create an Ingress and use the tls field to reference the Secret that is created in the previous step.
    cat <<EOF | kubectl create -f - 
    apiVersion: networking.k8s.io/v1beta1
    kind: Ingress
    metadata:
      name: test-test-ingress
    spec:
      #Reference the TLS certificate. 
      tls:
      - hosts:
        - foo.bar.com #The domain name associated with the TLS certificate. 
        secretName: tls-test-ingress
      rules:
      - host: tls-test-ingress.com
        http:
          paths:
          - path: /foo
            backend:
              serviceName: web1-svc
              servicePort: 80
    EOF
    cat <<EOF | kubectl create -f - 
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: test-test-ingress
    spec:
      #Reference the TLS certificate. 
      tls:
      - hosts:
        - foo.bar.com #The domain name associated with the TLS certificate.  
        secretName: tls-test-ingress
      rules:
      - host: tls-test-ingress.com
        http:
          paths:
          - path: /foo
            backend:
              service:
                name: web1-svc
                port:
                  number: 80
            pathType: ImplementationSpecific
    EOF
  3. After the Ingress is created, you must modify the hosts file or specify the actual domain name before you can use TLS to secure data transmission.
    You can access the web1-svc service by using https://tls-test-ingress.com/foo.

Configure mutual TLS authentication

The NGINX Ingress controller supports mutual TLS authentication. You may want to configure mutual TLS authentication between servers and clients to ensure the security of connections in specific scenarios.

  1. Run the following command to create a self-signed Certificate Authority (CA) certificate:
    openssl req -x509 -sha256 -newkey rsa:4096 -keyout ca.key -out ca.crt -days 356 -nodes -subj '/CN=Fern Cert Authority'

    Expected output:

    Generating a 4096 bit RSA private key
    .............................................................................................................++
    .....................................................................................++
    writing new private key to 'ca.key'
  2. Create a server certificate.
    1. Run the following command to generate a file that is used to request a server certificate:
      openssl req -new -newkey rsa:4096 -keyout server.key -out server.csr -nodes -subj '/CN=foo.bar.com'

      Expected output:

      Generating a 4096 bit RSA private key
      ................................................................................................................................++
      .................................................................++
      writing new private key to 'server.key'
    2. Run the following command to use the root certificate to sign the file and generate a server certificate:
      openssl x509 -req -sha256 -days 365 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt

      Expected output:

      Signature ok
      subject=/CN=foo.bar.com
      Getting CA Private Key
  3. Create a client certificate.
    1. Run the following command to generate a file that is used to request a client certificate:
      openssl req -new -newkey rsa:4096 -keyout client.key -out client.csr -nodes -subj '/CN=Fern'

      Expected output:

      Generating a 4096 bit RSA private key
      .......................................................................................................................................................................................++
      ..............................................++
      writing new private key to 'client.key'
      -----
    2. Run the following command to use the root certificate to sign the file and generate a client certificate:
      openssl x509 -req -sha256 -days 365 -in client.csr -CA ca.crt -CAkey ca.key -set_serial 02 -out client.crt

      Expected output:

      Signature ok
      subject=/CN=Fern
      Getting CA Private Key
  4. Run the following command to query the created certificate files:
    ls

    Expected output:

    ca.crt  ca.key  client.crt  client.csr  client.key  server.crt  server.csr  server.key
  5. Run the following command to create a Secret based on the created CA certificate:
    kubectl create secret generic ca-secret --from-file=ca.crt=ca.crt

    Expected output:

    secret/ca-secret created
  6. Run the following command to create a Secret based on the created server certificate:
    kubectl create secret generic tls-secret --from-file=tls.crt=server.crt --from-file=tls.key=server.key

    Expected output:

    secret/tls-secret created
  7. Run the following command to create an NGINX Ingress for testing purposes.
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1beta1
    kind: Ingress
    metadata:
      annotations:
        nginx.ingress.kubernetes.io/auth-tls-verify-client: "on"
        nginx.ingress.kubernetes.io/auth-tls-secret: "default/ca-secret"
        nginx.ingress.kubernetes.io/auth-tls-verify-depth: "1"
        nginx.ingress.kubernetes.io/auth-tls-pass-certificate-to-upstream: "true"
      name: nginx-test
      namespace: default
    spec:
      rules:
      - host: foo.bar.com
        http:
          paths:
          - backend:
              serviceName: http-svc
              servicePort: 80
            path: /
      tls:
      - hosts:
        - foo.bar.com
        secretName: tls-secret
    EOF
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        nginx.ingress.kubernetes.io/auth-tls-verify-client: "on"
        nginx.ingress.kubernetes.io/auth-tls-secret: "default/ca-secret"
        nginx.ingress.kubernetes.io/auth-tls-verify-depth: "1"
        nginx.ingress.kubernetes.io/auth-tls-pass-certificate-to-upstream: "true"
      name: nginx-test
      namespace: default
    spec:
      rules:
      - host: foo.bar.com
        http:
          paths:
          - backend:
              service:
                name: http-svc
                port: 
                  number: 80
            path: /
            pathType: ImplementationSpecific
      tls:
      - hosts:
        - foo.bar.com
        secretName: tls-secret
    EOF

    Expected output:

    ingress.networking.k8s.io/nginx-test configured
  8. Run the following command to query the IP address of the created Ingress:
    kubectl get ing

    The IP address in the ADDRESS field is the IP address of the created Ingress, as shown in the following output:

    NAME         HOSTS                    ADDRESS         PORTS     AGE
    nginx-test   foo.bar.com              39.102.XX.XX    80, 443   4h42m
  9. Run the following command to replace the IP address in the hosts file with the obtained IP address:
    sudo echo "39.102.XX.XX  foo.bar.com" >> /etc/hosts
    Verify the configuration:
    • The client does not provide the client certificate when it accesses the server
      curl --cacert ./ca.crt  https://foo.bar.com

      Expected output:

      <html>
      <head><title>400 No required SSL certificate was sent</title></head>
      <body>
      <center><h1>400 Bad Request</h1></center>
      <center>No required SSL certificate was sent</center>
      <hr><center>nginx/1.19.0</center>
      </body>
      </html>
    • The client provides the client certificate when it accesses the server
      curl --cacert ./ca.crt --cert ./client.crt --key ./client.key https://foo.bar.com

      Expected output:

      <!DOCTYPE html>
      <html>
      <head>
      <title>Welcome to nginx!</title>
      <style>
          body {
              width: 35em;
              margin: 0 auto;
              font-family: Tahoma, Verdana, Arial, sans-serif;
          }
      </style>
      </head>
      <body>
      <h1>Welcome to nginx!</h1>
      <p>If you see this page, the nginx web server is successfully installed and
      working. Further configuration is required.</p>
      
      <p>For online documentation and support please refer to
      <a href="http://nginx.org/">nginx.org</a>.<br/>
      Commercial support is available at
      <a href="http://nginx.com/">nginx.com</a>.</p>
      
      <p><em>Thank you for using nginx.</em></p>
      </body>
      </html>

Forward HTTPS requests from Services to backend containers

By default, the NGINX Ingress controller forwards HTTP requests to backend containers. If your backend service uses HTTPS, you can configure the NGINX Ingress controller to forward HTTPS requests to backend containers by adding the nginx.ingress.kubernetes.io/backend-protocol: "HTTPS" annotation.

The following template shows the configuration of the NGINX Ingress:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: backend-https
  annotations:
    # Note: You must set the backend protocol to HTTPS. 
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
  tls:
  - hosts:
    - <your-host-name>
    secretName: <your-secret-cert-name>
  rules:
  - host: <your-host-name>
    http:
      paths:
      - path: /
        backend:
          serviceName: <your-service-name>
          servicePort: <your-service-port>
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: backend-https
  annotations:
    # Note: You must set the backend protocol to HTTPS. 
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
  tls:
  - hosts:
    - <your-host-name>
    secretName: <your-secret-cert-name>
  rules:
  - host: <your-host-name>
    http:
      paths:
      - path: /
        backend:
          service:
            name: <your-service-name>
            port: 
              number: <your-service-port>
        pathType: ImplementationSpecific

Use regular expressions to specify domain names

By default, you cannot use regular expressions to specify domain names when you configure Ingresses for Kubernetes clusters. However, you can enable Ingresses to support regular expressions by adding the nginx.ingress.kubernetes.io/server-alias annotation.

  1. Create an NGINX Ingress. In the following example, the domain name is set to the regular expression ~^www\.\d+\.example\.com.
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1beta1
    kind: Ingress
    metadata:
      name: ingress-regex
      namespace: default
      annotations:
        nginx.ingress.kubernetes.io/server-alias: '~^www\.\d+\.example\.com$, abc.example.com'
    spec:
      rules:
      - host: foo.bar.com
        http:
          paths:
          - path: /foo
            backend:
              serviceName: http-svc1
              servicePort: 80
     EOF
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: ingress-regex
      namespace: default
      annotations:
        nginx.ingress.kubernetes.io/server-alias: '~^www\.\d+\.example\.com$, abc.example.com'
    spec:
      rules:
      - host: foo.bar.com
        http:
          paths:
          - path: /foo
            backend:
              service:
                name: http-svc1
                port:
                  number: 80
            pathType: ImplementationSpecific
    EOF
  2. Query the configuration of the NGINX Ingress controller.
    1. Run the following command to query the pods that are provisioned for the NGINX Ingress controller:
      kubectl get pods -n kube-system | grep nginx-ingress-controller

      Expected output:

      nginx-ingress-controller-77cd987c4c-c****         1/1     Running   0          1h
      nginx-ingress-controller-77cd987c4c-x****         1/1     Running   0          1h
    2. Run the following command to query the configuration of the NGINX Ingress controller. The output shows the effective configurations, such as the Server_Name field in this example.
      kubectl exec -n kube-system nginx-ingress-controller-77cd987c4c-c**** cat /etc/nginx/nginx.conf | grep -C3 "foo.bar.com"

      Expected output:

        ##start server foo.bar.com
        server {
      --
        server {
          server_name foo.bar.com abc.example.com ~^www\.\d+\.example\.com$ ;
          listen 80  ;
          listen 443  ssl http2 ;
      --
      --
          }
        }
        ##end server foo.bar.com
  3. Run the following command to query the IP address of the Ingress:
    kubectl get ing

    Expected output:

    NAME            HOSTS         ADDRESS          PORTS     AGE
    ingress-regex   foo.bar.com   101.37.XX.XX     80        11s
  4. Run the following commands to access a Service by using different Ingress rules.
    Replace IP_ADDRESS with the IP address obtained in the previous step.
    • Run the following command to access the Service through Host: foo.bar.com:
      curl -H "Host: foo.bar.com" <IP_ADDRESS>/foo

      Expected output:

      /foo
    • Run the following command to access the Service through Host: www.123.example.com:
      curl -H "Host: www.123.example.com" <IP_ADDRESS>/foo

      Expected output:

      /foo
    • Run the following command to access the Service through Host: www.321.example.com:
      curl -H "Host: www.321.example.com" <IP_ADDRESS>/foo

      Expected output:

      /foo

Specify wildcard domain names

In Kubernetes clusters, NGINX Ingresses support wildcard domain names. For example, you can specify the wildcard domain name *. ingress-regex.com for an Ingress.

  1. Create an NGINX Ingress by using the following template:
    $ cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1beta1
    kind: Ingress
    metadata:
      name: ingress-regex
      namespace: default
    spec:
      rules:
     - host: *.ingress-regex.com
        http:
          paths:
          - path: /foo
            backend:
              serviceName: http-svc1
              servicePort: 80
     EOF
    cat <<-EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: ingress-regex
      namespace: default
    spec:
      rules:
    - host: *.ingress-regex.com
        http:
          paths:
          - path: /foo
            backend:
              service:
                name: http-svc1
                port:
                  number: 80
            pathType: ImplementationSpecific
    EOF
  2. Run the following command to query the configuration of the NGINX Ingress controller. The output shows the effective configurations, such as the Server_Name field in this example.
    kubectl exec -n kube-system <ningx-ingress-pod-name> cat /etc/nginx/nginx.conf | grep -C3 "*.ingress-regex.com"
    Note Replace ningx-ingress-pod-name with the name of the pod that is provisioned for the NGINX Ingress controller.

    Expected output:

    ## start server *.ingress-regex.com
      server {
        server_name *.ingress-regex.com ;
        listen 80;
        listen [::]:80;
    ...
      }
      ## end server *.ingress-regex.com

    Expected output when the latest version of the NGINX Ingress controller is used:

    ## start server *.ingress-regex.com
      server {
        server_name ~^(?<subdomain>[\w-]+)\.ingress-regex\.com$ ;
        listen 80;
        listen [::]:80;
    ...
      }
      ## end server *.ingress-regex.com
  3. Run the following command to query the IP address of the Ingress:
    kubectl get ing

    Expected output:

    NAME            HOSTS                 ADDRESS           PORTS     AGE
    ingress-regex   *.ingress-regex.com   101.37.XX.XX      80        11s
  4. Run the following commands to access a Service by using different Ingress rules.
    Replace IP_ADDRESS with the IP address obtained in the previous step.
    • Run the following command to access the Service through Host: abc.ingress-regex.com:
      curl -H "Host: abc.ingress-regex.com" <IP_ADDRESS>/foo

      Expected output:

      /foo
    • Run the following command to access the Service through Host: 123.ingress-regex.com:
      curl -H "Host: 123.ingress-regex.com" <IP_ADDRESS>/foo

      Expected output:

      /foo
    • Run the following command to access the Service through Host: a1b1.ingress-regex.com:
      curl -H "Host: a1b1.ingress-regex.com" <IP_ADDRESS>/foo

      Expected output:

      /foo

Use annotations to implement canary releases

You can implement canary releases by adding annotations to Ingresses. To enable canary release, you must add the annotation nginx.ingress.kubernetes.io/canary: "true". This section describes how to use different annotations to implement canary releases.
  • nginx.ingress.kubernetes.io/canary-weight: This annotation allows you to set the percentage of requests that are sent to the specified Service. You can enter an integer from 0 to 100.
  • nginx.ingress.kubernetes.io/canary-by-header: This annotation enables traffic splitting based on the request header. If the header value is always, requests are distributed to new Services. If the header value is never, requests are not distributed to new Services. If the header value is neither always nor never, requests are distributed to new Services based on other matching rules in descending order of priority.
  • nginx.ingress.kubernetes.io/canary-by-header-value and nginx.ingress.kubernetes.io/canary-by-header-value: When the values of header and header-value in the requests match the specified values in the annotations, requests are distributed to new Services. Otherwise, if the header value is set to other values, requests are distributed to new Services based on other matching rules in descending order of priority.
  • nginx.ingress.kubernetes.io/canary-by-cookie: This annotation enables cookie-based traffic splitting. If the cookie value is always, requests are distributed to new Services. If the cookie value is never, requests are not distributed to new Services.
The following sample code shows how these annotations are used. For more information, see Use the NGINX Ingress controller to implement canary releases and blue-green releases.
  • Weight-based canary release: Set the weight of Services to 20%.
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        kubernetes.io/ingress.class: nginx
        nginx.ingress.kubernetes.io/canary: "true"
        nginx.ingress.kubernetes.io/canary-weight: "20"
  • Header-based canary release: When the request header is ack:always, requests are forwarded to new Services. When the request header is ack:never, requests are not distributed to new Services. If the header is neither ack:always nor ack:never, requests are distributed to new Services based on weights.
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        kubernetes.io/ingress.class: nginx
        nginx.ingress.kubernetes.io/canary: "true"
        nginx.ingress.kubernetes.io/canary-weight: "50"
        nginx.ingress.kubernetes.io/canary-by-header: "ack"
  • Header-based canary release with custom header values: If the request header is ack:alibaba, requests are distributed to new Services. Otherwise, requests are distributed to new Services based on weights.
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        kubernetes.io/ingress.class: nginx
        nginx.ingress.kubernetes.io/canary: "true"
        nginx.ingress.kubernetes.io/canary-weight: "20"
        nginx.ingress.kubernetes.io/canary-by-header: "ack"
        nginx.ingress.kubernetes.io/canary-by-header-value: "alibaba"
  • Cookie-based canary release: If the request header is not matched and the request cookie is hangzhou_region=always, requests are distributed to new Services.
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      annotations:
        kubernetes.io/ingress.class: nginx
        nginx.ingress.kubernetes.io/canary: "true"
        nginx.ingress.kubernetes.io/canary-weight: "20"
        nginx.ingress.kubernetes.io/canary-by-header: "ack"
        nginx.ingress.kubernetes.io/canary-by-header-value: "alibaba"
        nginx.ingress.kubernetes.io/canary-by-cookie: "hangzhou_region"
Note
  • Cookie-based canary release does not support custom settings. The cookie value must be always or never.
  • Canary releases that use different rules take effect in the following order: header-based > cookie-based > weight-based.

Use cert-manager to apply for a free TLS certificate

cert-manager is an open source tool used to manage cloud-native certificates. You can use cert-manager in Kubernetes clusters to apply for TLS certificates and enable auto-renewal for the certificates. This section describes how to apply for a free certificate and enable auto-renewal for the certificate by using cert-manager.

  1. Run the following command to deploy cert-manager:
    kubectl apply -f https://github.com/cert-manager/cert-manager/releases/latest/download/cert-manager.yaml
    Note The YAML template referenced in the preceding command can be used to deploy cert-manager only in ACK clusters. For more information about how to deploy cert-manager in ASK clusters, see Use cert-manager to apply for a free TLS certificate.
  2. Run the following command to query the status of the pod:
    kubectl get pods -n cert-manager

    Expected output:

    NAME                     READY   STATUS    RESTARTS   AGE
    cert-manager-1           1/1     Running   0          2m11s
    cert-manager-cainjector  1/1     Running   0          2m11s
    cert-manager-webhook     1/1     Running   0          2m10s
  3. Run the following command to create a ClusterIssuer:
    cat <<EOF | kubectl apply -f -
    apiVersion: cert-manager.io/v1
    kind: ClusterIssuer
    metadata:
      name: letsencrypt-prod-http01
    spec:
      acme:
        server: https://acme-v02.api.letsencrypt.org/directory
        email: <your_email_name@gmail.com>  #Replace the value with your email address. 
        privateKeySecretRef:
          name: letsencrypt-http01
        solvers:
        - http01: 
            ingress:
              class: nginx
    EOF
  4. Run the following command to query the created ClusterIssuer:
    kubectl get clusterissuer

    Expected output:

    NAME                         READY   AGE
    letsencrypt-prod-http01      True    17s
  5. Run the following command to create an NGINX Ingress:
    cat <<EOF | kubectl apply -f -
    apiVersion: extensions/v1beta1
    kind: Ingress
    metadata:
      name: ingress-tls
      annotations:
        kubernetes.io/ingress.class: "nginx"
        cert-manager.io/cluster-issuer: "letsencrypt-prod-http01"
    spec:
      tls:
      - hosts:
        - <your_domain_name>        # Replace the value with your domain name. 
        secretName: ingress-tls   
      rules:
      - host: <your_domain_name>    # Replace the value with your domain name. 
        http:
          paths:
          - path: /
            backend:
              serviceName: <your_service_name>  # Replace the value with the Service name. 
              servicePort: <your_service_port>  # Replace the value with the Service port. 
    EOF
    cat <<EOF | kubectl apply -f -
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: ingress-tls
      annotations:
        kubernetes.io/ingress.class: "nginx"
        cert-manager.io/cluster-issuer: "letsencrypt-prod-http01"
    spec:
      tls:
      - hosts:
        - <your_domain_name>        # Replace the value with your domain name. 
        secretName: ingress-tls   
      rules:
      - host: <your_domain_name>    # Replace the value with your domain name. 
        http:
          paths:
          - path: /
            backend:
              service:
                name: <your_service_name>  # Replace the value with the Service name. 
                port: 
                  number: <your_service_port>  # Replace the value with the Service port. 
            pathType: ImplementationSpecific
    EOF
    Note The domain name that you use to replace your_domain_name in the template must meet the following conditions:
    • The domain name cannot exceed 64 characters in length.
    • The domain name cannot be a wildcard domain name.
    • The domain name is accessible from the Internet over HTTP.
  6. Run the following command to query the certificate:
    kubectl get cert

    Expected output:

    NAME          READY   SECRET        AGE
    ingress-tls   True    ingress-tls   52m
    Note If the value in the READY field is not True, you can query the status of the certificate by running the kubectl describe cert ingress-tls command.
  7. Run the following command to query the Secret of the certificate:
    kubectl get secret  ingress-tls

    Expected output:

    NAME          TYPE                DATA   AGE
    ingress-tls   kubernetes.io/tls   2      2m
  8. You can enter https:[website domain name] into the address bar of your browser to access the specified domain name.