istio.io/content/en/docs/tasks/traffic-management/ingress/ingress-sni-passthrough/index.md

title	description	weight	keywords	aliases	test
Ingress Gateway without TLS Termination	Describes how to configure SNI passthrough for an ingress gateway.	30	traffic-management ingress https	/docs/examples/advanced-gateways/ingress-sni-passthrough/	yes

The Securing Gateways with HTTPS task describes how to configure HTTPS ingress access to an HTTP service. This example describes how to configure HTTPS ingress access to an HTTPS service, i.e., configure an ingress gateway to perform SNI passthrough, instead of TLS termination on incoming requests.

The example HTTPS service used for this task is a simple NGINX server. In the following steps you first deploy the NGINX service in your Kubernetes cluster. Then you configure a gateway to provide ingress access to the service via host nginx.example.com.

Generate client and server certificates and keys

For this task you can use your favorite tool to generate certificates and keys. The commands below use openssl

1. Create a root certificate and private key to sign the certificate for your services:

   {{< text bash >}} $ openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -subj '/O=example Inc./CN=example.com' -keyout example.com.key -out example.com.crt {{< /text >}}

2. Create a certificate and a private key for nginx.example.com:

   {{< text bash >}} $ openssl req -out nginx.example.com.csr -newkey rsa:2048 -nodes -keyout nginx.example.com.key -subj "/CN=nginx.example.com/O=some organization" $ openssl x509 -req -days 365 -CA example.com.crt -CAkey example.com.key -set_serial 0 -in nginx.example.com.csr -out nginx.example.com.crt {{< /text >}}

Deploy an NGINX server

1. Create a Kubernetes Secret to hold the server's certificate.

   {{< text bash >}} $ kubectl create secret tls nginx-server-certs --key nginx.example.com.key --cert nginx.example.com.crt {{< /text >}}

2. Create a configuration file for the NGINX server:

   {{< text bash >}} $ cat <<\EOF > ./nginx.conf events { }

   http { log_format main '$remote_addr - $remote_user [$time_local] $status ' '"$request" $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/access.log main; error_log /var/log/nginx/error.log;

   server { listen 443 ssl;

   root /usr/share/nginx/html;
   index index.html;
   
   server_name nginx.example.com;
   ssl_certificate /etc/nginx-server-certs/tls.crt;
   ssl_certificate_key /etc/nginx-server-certs/tls.key;
   

   } } EOF {{< /text >}}

3. Create a Kubernetes ConfigMap to hold the configuration of the NGINX server:

   {{< text bash >}} $ kubectl create configmap nginx-configmap --from-file=nginx.conf=./nginx.conf {{< /text >}}

4. Deploy the NGINX server:

   {{< text bash >}} $ cat <<EOF | istioctl kube-inject -f - | kubectl apply -f - apiVersion: v1 kind: Service metadata: name: my-nginx labels: run: my-nginx spec: ports:

   • port: 443 protocol: TCP selector: run: my-nginx

   ---

   apiVersion: apps/v1 kind: Deployment metadata: name: my-nginx spec: selector: matchLabels: run: my-nginx replicas: 1 template: metadata: labels: run: my-nginx spec: containers: - name: my-nginx image: nginx ports: - containerPort: 443 volumeMounts: - name: nginx-config mountPath: /etc/nginx readOnly: true - name: nginx-server-certs mountPath: /etc/nginx-server-certs readOnly: true volumes: - name: nginx-config configMap: name: nginx-configmap - name: nginx-server-certs secret: secretName: nginx-server-certs EOF {{< /text >}}

5. To test that the NGINX server was deployed successfully, send a request to the server from its sidecar proxy without checking the server's certificate (use the -k option of curl). Ensure that the server's certificate is printed correctly, i.e., common name (CN) is equal to nginx.example.com.

   {{< text bash >}} kubectl exec "(kubectl get pod -l run=my-nginx -o jsonpath={.items..metadata.name})" -c istio-proxy -- curl -v -k --resolve nginx.example.com:443:127.0.0.1 https://nginx.example.com ... SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384 ALPN, server accepted to use http/1.1 Server certificate: subject: CN=nginx.example.com; O=some organization start date: May 27 14:18:47 2020 GMT expire date: May 27 14:18:47 2021 GMT issuer: O=example Inc.; CN=example.com SSL certificate verify result: unable to get local issuer certificate (20), continuing anyway.

   GET / HTTP/1.1 User-Agent: curl/7.58.0 Host: nginx.example.com ... < HTTP/1.1 200 OK

   < Server: nginx/1.17.10 ...

   <html> <head> ... {{< /text >}}

Configure an ingress gateway

1. Define a Gateway with a server section for port 443. Note the PASSTHROUGH TLS mode which instructs the gateway to pass the ingress traffic AS IS, without terminating TLS.

   {{< text bash >}} $ kubectl apply -f - <<EOF apiVersion: networking.istio.io/v1alpha3 kind: Gateway metadata: name: mygateway spec: selector: istio: ingressgateway # use istio default ingress gateway servers:

   • port: number: 443 name: https protocol: HTTPS tls: mode: PASSTHROUGH hosts:
     • nginx.example.com EOF {{< /text >}}

2. Configure routes for traffic entering via the Gateway:

   {{< text bash >}} $ kubectl apply -f - <<EOF apiVersion: networking.istio.io/v1alpha3 kind: VirtualService metadata: name: nginx spec: hosts:

   • nginx.example.com gateways:
   • mygateway tls:
   • match:
     • port: 443 sniHosts:
       • nginx.example.com route:
     • destination: host: my-nginx port: number: 443 EOF {{< /text >}}

3. Follow the instructions in Determining the ingress IP and ports to define the SECURE_INGRESS_PORT and INGRESS_HOST environment variables.

4. Access the NGINX service from outside the cluster. Note that the correct certificate is returned by the server and it is successfully verified (SSL certificate verify ok is printed).

   {{< text bash >}} $ curl -v --resolve "nginx.example.com:$SECURE_INGRESS_PORT:$INGRESS_HOST" --cacert example.com.crt "https://nginx.example.com:$SECURE_INGRESS_PORT" Server certificate: subject: CN=nginx.example.com; O=some organization start date: Wed, 15 Aug 2018 07:29:07 GMT expire date: Sun, 25 Aug 2019 07:29:07 GMT issuer: O=example Inc.; CN=example.com SSL certificate verify ok.

   < HTTP/1.1 200 OK < Server: nginx/1.15.2 ...

   <html> <head> {{< /text >}}

Cleanup

1. Remove created Kubernetes resources:

   {{< text bash >}} $ kubectl delete secret nginx-server-certs $ kubectl delete configmap nginx-configmap $ kubectl delete service my-nginx $ kubectl delete deployment my-nginx $ kubectl delete gateway mygateway $ kubectl delete virtualservice nginx {{< /text >}}

2. Delete the certificates and keys:

   {{< text bash >}} $ rm example.com.crt example.com.key nginx.example.com.crt nginx.example.com.key nginx.example.com.csr {{< /text >}}

3. Delete the generated configuration files used in this example:

   {{< text bash >}} $ rm ./nginx.conf {{< /text >}}