Enabling SSL for Cloud Endpoints with ESPv2

This page explains how to enable a Secure Sockets Layer (SSL) port when deploying Extensible Service Proxy V2 (ESPv2) with Google Kubernetes Engine, Kubernetes, or Compute Engine. You may want to enable an SSL port for your deployed Endpoints service for some use cases.

Before you begin, make sure that you have already reviewed the tutorials for your chosen service type and environment, and know how to deploy ESPv2 without SSL.

Configuring your SSL keys and certificates

To configure your SSL port to serve HTTPS requests, follow the steps below:

  1. Check to ensure that your SSL key file is named server.key and your certificate file is named server.crt. For testing, you can generate a self-signed server.key and server.crt using OpenSSL with the following command:

    openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
    -keyout ./server.key -out ./server.crt
  2. Specify both CN and subjectAltName in your server certificate. The value of these attributes should match the DNS or IP used by clients to call your service; otherwise, the SSL handshake will fail.

Enabling SSL for ESPv2 on Kubernetes

To enable the SSL port for ESPv2 on Kubernetes:

  1. Create a Kubernetes secret with your SSL key and certificate:

    kubectl create secret generic esp-ssl \
      --from-file=./server.crt --from-file=./server.key
  2. Edit the Kubernetes configuration files, for example, echo-ssl.yaml, as shown in the following snippet:

          app: esp-echo
        - name: esp-ssl
            secretName: esp-ssl
        - name: esp
          image: gcr.io/endpoints-release/endpoints-runtime:2
          args: [
            "--listener_port", "9000",
            "--backend", "",
            "--service", "SERVICE_NAME",
            "--rollout_strategy", "managed",
            "--ssl_server_cert_path", "/etc/esp/ssl",
            - containerPort: 9000
          - mountPath: /etc/esp/ssl
            name: esp-ssl
            readOnly: true
        - name: echo
          image: gcr.io/endpoints-release/echo:latest
            - containerPort: 8081

    Note: The configuration sample displays the lines that need to be edited. To deploy the file to Cloud Endpoints, the complete configuration file is required.

  3. Mount the Kubernetes secrets you created as volumes, following the directions in the Kubernetes volumes page.

  4. Start up ESPv2 as described in Specifying startup options for ESPv2, but make sure you add the startup flag --ssl_server_cert_path to specify the path for the mounted certificate files.

  5. Start the service with the updated Kubernetes configuration file by using kubectl.

    kubectl apply -f echo-ssl.yaml

  6. Generate the root certificate for the client by using the following OpenSSL command:

       openssl x509 -in ./server.crt -out ./client.pem -outform PEM

    If the client is using curl, the file client.pem can be used in the --caroot flag. For gRPC, the client.pem is used as the root certificate file of the SSL credential for gRPC channel.

Update SSL certificates

It is important to update your SSL certificates periodically. To update your SSL certificates, you must perform the following steps:

  • Create new certificates, as described in Step 1 above.
  • Mount the new certificates to the Kubernetes secrets, as described in Step 3 above.
  • Update the ESPv2 Kubernetes deployment, as described in Step 5 above.
  • Regenerate the client root certificate file, as described in Step 6 above.

Enabling SSL for ESPv2 on Compute Engine

To enable SSL on Compute Engine, first copy the server.key and server.crt files to your Compute Engine instance's /etc/nginx/ssl folder, using the following steps:

  1. Run the following command and replace INSTANCE_NAME with the name of your Compute Engine instance:

    gcloud compute scp server.* INSTANCE-NAME
  2. Connect to the instance using ssh.

    gcloud compute ssh INSTANCE-NAME
  3. In the instance VM box, make the directory and copy in the files:

      sudo mkdir -p /etc/esp/ssl
      sudo cp server.* /etc/esp/ssl/
  4. Follow the instructions for your service type to deploy with Docker. When you run the ESPv2 Docker container, use this command:

    sudo docker run --name=esp \
     --detach \
     --publish=443:9000 \
     --net=esp_net \
     --volume=/etc/esp/ssl:/etc/esp/ssl \
      gcr.io/endpoints-release/endpoints-runtime:2 \
     --service=SERVICE_NAME \
     --rollout_strategy=managed \
     --backend=echo:8080 \
     --ssl_server_cert_path=/etc/esp/ssl \

    As compared to the non-SSL docker run command, the SSL version of the command creates a different configuration. For example, the SSL command:

    • Mounts the folder with the key and CRT files to the container by using --volume.
    • Uses --ssl_server_cert_path=/etc/esp/ssl to tell ESPv2 to find the server certificate files server.key and server.crt in the /etc/esp/ssl folder.
    • Changes the port mapping flag --publish. Incoming requests to HTTPS port 443 are mapped to ESPv2 port 9000.

Update SSL certificates

It is important to update your SSL certificates periodically. To update your SSL certificates, you must perform the following steps:

  • Create new certificates and copy them into VM instances, as described in Step 1 above.
  • Copy the new certificates into the /etc/esp/ssl directory, as described in Step 3 above.
  • Stop and restart the ESPv2 container using the sudo docker run command, as described in Step 4 above.

Testing the SSL port

To make the testing the SSL port easier, set the following environment variables:

  1. Set IP_ADDRESS to the IP address of the Compute Engine instance with the new SSL certificate.

  2. Set ENDPOINTS_KEY to a valid API key.

Once the SSL port is enabled, you can use HTTPS to send requests to the Extensible Service Proxy. If your certificate is self-signed, use -k to turn on the insecure option in curl:

curl -k -d '{"message":"hello world"}' -H "content-type:application/json" \

Alternatively, generate the certificate in pem format and use the --cacert option to use the self-signed certificate in curl, as shown below:

  openssl x509 -in server.crt -out client.pem -outform PEM
  curl --cacert "./client.pem" -d '{"message":"hello world"}' -H "content-type:application/json" \