Setting up an HTTP-to-HTTPS redirect for external global external HTTP(S) load balancer (classic)

This page is for a global external HTTP(S) load balancer (classic) only. If you are using a load balancer in a different mode, see one of the following pages:

This example demonstrates how to use URL redirects to redirect all requests from port 80 (HTTP) to port 443 (HTTPS).

HTTPS uses TLS (SSL) to encrypt HTTP requests and responses, making it safer and more secure. A website that uses HTTPS has https:// in the beginning of its URL instead of http://.

For new HTTPS load balancers

If you're creating a new HTTPS load balancer, you can use the Google Cloud Cloud Console to set up an HTTP-to-HTTPS redirect.

While creating the HTTPS load balancer's frontend, use the following steps:

  1. In the Google Cloud Console, go to the load balancer's configuration page.

    Go to Load Balancing (classic)

  2. Click Frontend configuration.
  3. Under Protocol, select HTTPS (includes HTTP/2).
  4. Under IP address, select a reserved IP address.
  5. Click the Enable HTTP to HTTPS Redirect checkbox to create the redirect.

You must select the HTTPS protocol and use a reserved IP address (not ephemeral) to be able to select the checkbox.

HTTP-to-HTTPS redirect checkbox (click to enlarge)
HTTP-to-HTTPS redirect checkbox (click to enlarge)

Depending on your backend type, use the Cloud Console instructions from one of the following guides to complete this setup:

Setting the Enable HTTP to HTTPS Redirect checkbox automatically creates an additional partial HTTP load balancer consisting of a URL map, a forwarding rule, and a target HTTP proxy. This partial HTTP load balancer uses the same IP address as your HTTPS load balancer and redirects HTTP requests to your load balancer's HTTPS frontend. It uses 301 Moved Permanently as the default redirect response code.

After the HTTPS load balancer is created, you can see the partial HTTP load balancer in the list of load balancers, with a -redirect suffix. Test your setup by using the steps in Testing the HTTP-to-HTTPS redirect.

For existing load balancers

If you already have an external HTTPS load balancer (called here LB1) that is serving HTTPS traffic on port 443, you must create a partial external HTTP load balancer (called here LB2) with the following setup:

  • The same frontend IP address used by LB1
  • A redirect configured in the URL map

This partial HTTP load balancer uses the same IP address as your HTTPS load balancer and redirects HTTP requests to your load balancer's HTTPS frontend.

This architecture is shown in the following diagram.

HTTP-to-HTTPS redirect configuration (click to enlarge)
HTTP-to-HTTPS redirect configuration

Redirecting traffic to your HTTPS load balancer

After you have verified that your external HTTPS load balancer (LB1) is working, you can create the partial external HTTP load balancer (LB2) with its frontend configured to redirect traffic to LB1.

This example uses the 301 response code. You can instead use a different response code.

To configure the redirect with gcloud, you must import a YAML file and make sure that your target HTTP proxy points to the URL map that redirects traffic. If you're using the Cloud Console, this is handled for you.

Regional external HTTP(S) load balancers aren't supported in the Cloud Console.

Console

Start the configuration
  1. In the Google Cloud Console, go to the Load balancing page.

    Go to Load balancing

  2. Under HTTP(S) load balancing, click Start configuration.
  3. Select From Internet to my VMs, and then click Continue.
  4. Under Advanced traffic management, select Classic HTTP(S) Load Balancer.
  5. For the Name of the load balancer, enter something like http-redirect.
  6. Keep the window open to continue.
Skip the backend configuration
  1. Skip the Backend Configuration section.
Configure the redirect in the URL map
  1. In the left column of the page, click Host and path rules.
  2. Select Advanced host and path rule (URL redirect, URL rewrite).
  3. Under Action, select Redirect the client to different host/path.
  4. Leave the Prefix redirect field blank.
  5. Under Path redirect, select Prefix redirect.
  6. Leave the Path value field blank.
  7. Under Redirect response code, select 301 - Moved Permanently.
  8. Under HTTPS redirect, select Enable.
  9. Click Done.
  10. Keep the load balancer configuration page open to continue.
Configure the HTTP forwarding rule with the same IP address used in LB1
  1. On the load balancer configuration page, click Frontend configuration.
  2. Set Protocol to HTTP.
  3. Set IP address to the *same* IP address that you use for your HTTPS load balancer.
  4. Ensure that Port is set to 80 to allow HTTP traffic.
  5. Click Done.
  6. Keep the window open to continue.
  7. Review the configuration
  8. In the left panel, click Review and finalize.
  9. Compare your settings to what you intended to create.
  10. If everything looks correct, click Create.

When you are finished, the Cloud Console displays two load balancers, as follows.

Both load balancers

The Cloud Console displays information about your web-map-http load balancer as follows.

HTTP load balancer

gcloud

  1. Create a YAML file /tmp/web-map-http.yaml. This example uses MOVED_PERMANENTLY_DEFAULT as the response code.
  2.        kind: compute#urlMap
           name: web-map-http
           defaultUrlRedirect:
             redirectResponseCode: MOVED_PERMANENTLY_DEFAULT
             httpsRedirect: True
           tests:
           - description: Test with no query parameters
             host: example.com
             path: /test/
             expectedOutputUrl: https://example.com/test/
             expectedRedirectResponseCode: 301
           - description: Test with query parameters
             host: example.com
             path: /test/?parameter1=value1&parameter2=value2
             expectedOutputUrl: https://example.com/test/?parameter1=value1&parameter2=value2
             expectedRedirectResponseCode: 301
           
  3. Validate the URL map.
  4.        gcloud compute url-maps validate --source /tmp/web-map-http.yaml
           

    If the tests pass and the command outputs a success message, save the changes to the URL map.

  5. Create the HTTP load balancer's URL map by importing the YAML file. The name for this URL map is web-map-http.
  6.        gcloud compute url-maps import web-map-http \
               --source /tmp/web-map-http.yaml \
               --global
           

    If you are updating an existing URL map, the following prompt appears:

           Url Map [web-map-http] will be overwritten.
    
           Do you want to continue (Y/n)?
           

    To continue, press Y.

  7. Verify that the URL map is updated. Your HTTP load balancer's URL map should look something like this:
  8.        gcloud compute url-maps describe web-map-http
           
           creationTimestamp: '2020-03-23T10:53:44.976-07:00'
           defaultUrlRedirect:
             httpsRedirect: true
             redirectResponseCode: MOVED_PERMANENTLY_DEFAULT
           fingerprint: 3A5N_RLrED8=
           id: '2020316695093397831'
           kind: compute#urlMap
           name: web-map-http
           selfLink: https://www.googleapis.com/compute/v1/projects/PROJECT_ID/global/urlMaps/web-map-http
           
  9. Create a new target HTTP proxy or update an existing target HTTP proxy, using web-map-http as the URL map.
  10.        gcloud compute target-http-proxies create http-lb-proxy \
               --url-map=web-map-http \
               --global
           
    OR
           gcloud compute target-http-proxies update http-lb-proxy \
               --url-map=web-map-http \
               --global
           
  11. Create a forwarding rule to route incoming requests to the proxy. The --address flag specifies lb-ipv4-1, which is the same IP address used for the external HTTPS load balancer.
  12.        gcloud compute forwarding-rules create http-content-rule \
               --load-balancing-scheme=EXTERNAL \
               --network-tier=PREMIUM \
               --address=lb-ipv4-1 \
               --global \
               --target-http-proxy=http-lb-proxy \
               --ports=80
           

Adding a custom header

Optionally, add the HTTP Strict-Transport-Security header to your HTTPS load balancer's backend service, as follows:

  • Header name: Strict-Transport-Security
  • Header value: max-age=31536000; includeSubDomains; preload

This setting sends the custom header to the client so that the next time the client tries to access the URL through HTTP, the browser does the redirect.

To add the custom header to the backend service configuration, use the --custom-response-header flag.

gcloud compute backend-services update BACKEND_SERVICE_NAME_LB1 \
    --global \
    --custom-response-header='Strict-Transport-Security:max-age=31536000; includeSubDomains; preload'

For more information, see Creating custom headers.

Testing the HTTP-to-HTTPS redirect

Note the reserved IP address that you are using for both load balancers.

gcloud compute addresses describe lb-ipv4-1 \
    --format="get(address)" \
    --global

In this example, assume that the reserved IP address is 34.98.77.106. The http://34.98.77.106/ URL redirects to https://34.98.77.106/.

After a few minutes have passed, you can test this by running the following curl command.

curl -v http://hostname.com

Sample output:

* Connected to 34.98.77.106 (34.98.77.106) port 80 (#0)
> GET / HTTP/1.1
> Host: hostname.com
> User-Agent: curl/7.64.0
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< Cache-Control: private
< Content-Type: text/html; charset=UTF-8
< Referrer-Policy: no-referrer
< Location: https://hostname.com
< Content-Length: 220
< Date: Fri, 30 Jul 2021 21:32:25 GMT
<
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="https://hostname.com">here</A>.
</BODY></HTML>
* Connection #0 to host hostname.com left intact

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