Set up an HTTP-to-HTTPS redirect for regional external Application Load Balancers

This page shows you how to set up an HTTP-to-HTTPS redirect for the regional external Application Load Balancer. This page is for a regional external Application Load Balancer only. If you use a load balancer in a different mode, see one of the following pages:

This example shows how to use URL map redirects to redirect all requests from HTTP to HTTPS. This example shows how you set up redirects by using the well-known ports 80 (for HTTP) and 443 (for HTTPS). However, you're not required to use these specific port numbers. Each forwarding rule for an Application Load Balancer can reference a single port from 1-65535.

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

Regional external Application Load Balancers don't support creating HTTP-to-HTTPS redirects while creating a new load balancer. You'll need to first use the instructions from the Compute Engine backend guide to create a new load balancer. You can then use the instructions in the next section to set up a redirect for all requests from HTTP to HTTPS.

This procedure assumes that you already have an external HTTPS load balancer that is serving HTTPS traffic on port 443.

For existing load balancers

If you already have an HTTPS Application Load Balancer (called here LB1) that is serving HTTPS traffic on port 443, you must create a partial HTTP Application 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 architecture.
Figure 2. HTTP-to-HTTPS redirect configuration architecture (click to enlarge).

Redirecting traffic to your HTTPS load balancer

After you have verified that your HTTPS load balancer (LB1) is working, you can create the partial 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 Google Cloud console, this is handled for you.

Regional external Application Load Balancers aren't supported in the Google Cloud console.

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

    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.

  3. Verify that the URL map is updated. Your HTTP load balancer's URL map should look something like this:
    4.        gcloud compute url-maps describe web-map-http \
           --region=REGION
       
           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/regions/REGION/urlMaps/web-map-http
  4. Create a new target HTTP proxy or update an existing target HTTP proxy, using web-map-http as the URL map.
    5.        gcloud compute target-http-proxies create http-lb-proxy \
           --url-map=web-map-http \
           --region=REGION
    OR 
            gcloud compute target-http-proxies update http-lb-proxy \
           --url-map=web-map-http \
           --region=REGION
  5. 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.
    6.        gcloud compute forwarding-rules create http-content-rule \
           --load-balancing-scheme=EXTERNAL_MANAGED \
           --address=lb-ipv4-1 \
           --network-tier=STANDARD \
           --region=REGION \
           --target-http-proxy=http-lb-proxy \
           --target-http-proxy-region=REGION \
           --ports=80

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)" 

    --region=REGION

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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