Request for Documentation: Document client/server url schemas limitations for custom mobile apps

[mm-cloud-bot]

Mattermost user stu.doherty from https://community-daily.mattermost.com has requested the following be documented:

Due to changes in our SAML auth flow any customer building their own version of the mobile client (either because they need to host the Push Proxy themselves, OR they have their own customizations they're applying to the client) will need to be aware of a few things:

1. If they want to allow users to simultaneously run the App Store versions of Mattermost, in addition to the custom company version, they will need to adapt the URL schemes used for the app in the build, as well as configure those schemes on the server using [App Custom URL Schemes](https://docs.mattermost.com/configure/configuration-settings.html#app-custom-url-schemes).  Method to adapt on mobile is still to be improved, but requires modifications in a few `mattermost-mobile` source files for now.
They also need to be aware that the bundleid for the application should not include `rnbeta` (_exact restriction to be confirmed_)
2. This same change would be required in a custom build of the Mattermost Desktop Application (_To be confirmed_).
3. The mobile and desktop custom clients would no longer be able to log into other Mattermost servers (unless they had the same custom app schema configuration change).

NOTE:  I believe this is not an issue for customers who have `inAppSessionAuth == true` in their MDM configuration [App Config Docs](https://docs.mattermost.com/deploy/mobile-appconfig.html)

... More to come...

See the original post here.

This issue was generated from Mattermost using the Doc Up plugin.

[cwarnermm]

@sadohert - Can you help clarify what's needed for this docs request, please?