Is this a supported approach, and if so, are there any special configuration requirements regarding authentication, security zones, or cross-origin restrictions?
Any examples or step by step guides would be appreciated. Thanks!
You'll need to disable the X-Frame-Options header in your Gateway Configuration File. Like this, where the # needs to not conflict with any other parameters listed in that file, see here: wrapper.java.additional.#=-Dignition.http.header.x_frame_options.enabled=false
This requires a gateway restart once you Java Additional Parameter.
I can add that this is where you edit the ignition.conf file if you have selected the standard install format: C:\Program Files\Inductive Automation\Ignition\data
If its stuck on Initializing Client, I believe you'll have to setup SSL on these gateway and use HTTPS instead, then add 2 more parameters into the configuration file: wrapper.java.additional.#=-Dignition.http.session.cookie.same-site.enabled=true wrapper.java.additional.#=-Dignition.http.session.cookie.same-site.value=None
This can be done with a self signed certification. If this is you first time setting up SSL in Ignition I recommended not to enable the Force Secure Redirect option in the Web Server settings, by leaving this off you will still be able to access the gateway incase the SSL setup doesn't work. For testing you can use localhost as the domain on the self signed certificate, otherwise you can add a IP address down in the Subject Alternative Names.
Be aware that the end-user's browser now has to reach both gateways, and your front-end isn't reducing the workload on the backend as would be expected. The canonical solution would be to use a remote tag provider or MQTT to move live data to the front end so the front end can display the view directly.