CORS for App Proxy
There should be CORS setting available on App Proxy just like we have the CORS available for App Services.
Making calls from Azure Apps into an Azure App Proxy App is a very common scenario, especially when on-prem applications are surfaced externally using App proxy.
We are looking at enabling a feature that focuses on supporting CORS preflight requests between two applications. This works by allowing you to configure the response and have App Proxy handle it on behalf of the app.
A pre-requisite for this feature to work is that the user must be able to authenticate into the second application in order to avoid a CORS issue from the login flow into the second app.
To avoid this the user will have to make sure they have already accessed the 2nd application before the CORS request, and has valid credentials. This should work for wildcard apps and can also be achieved by adding a fake link / image to the 2nd application in the first application.
We would love to get your feedback on this requirement and if this is something that will fit your use case.
We are having the same issue in our organization. Exposing multiple resources that reference each other, but are then blocked because of this limitation.
Domer, Michael commented
can someone define "Soon". We are moving off of 2010 and need this for the new intranet via App Proxy. Please update.
John Atwood commented
You can work around this limitation by using an Azure Function Proxy to proxy your App Proxy App and set CORS allowed origins: