Add endpoint for gateway discovery

[xpufx]

I have a little app inside of which I can provide a dynamic upload destination interface if I can get a list of enabled gateways from a matterbridge instance. Some basic list that is unique enough to identify all separate destinations would be fine. The server side can be configured according to the user's needs.

[selfhoster1312]

Hi, thanks for the suggestion. I'm not sure i understand the detail of what you mean. Do you want an API to dynamically create gateways? A read-only API to list existing gateways? If so, should it return the entire config?

It would be useful if you would describe what you want in greater detail :)

EDIT: probably related #211

[xpufx]

EDIT: probably related #211

Yes that is the full extend of what I personally need. I have a little app for uploading files on which I want to add matterbridge support. If the available providers are discoverable I can auto configure them as upload destinations. It would proabably be useful for others in other ways so maybe spending some time on the implementation and output format is worthwhile.

[selfhoster1312]

Looking at the example in your PR #211, do you realize you can't join the channel with that information? Maybe that's OK and you only need the channel name?

Right now i don't understand how this would be useful unless you have your own mapping telling your backend to send files which have selected "bridge-1" to "#general" on "irc.libera.chat" (the IRC server address is not visible in your example JSON). In your example, only the matrix address is in fact global and correct for your 3rd party service to pick up. Is that on purpose?

[xpufx]

I am not sure I understand the question but in my setup the operator would have to configure the backend to be one destination per bridge setting because I don't want to upload to more than one destination at a time. As far as joining a channel, that's not done at the app side. A preconfigured bot user sits in the channel. IRC is a special case in my app and it uploads the file to a public share provider and only posts the url to the channel via that bot as IRC does not really do files. I could have used an existing bot but getting the other transport options for free sounded interesting. That's why I picked matterbridge as a proivder to add in my app.

I am already using a patched version so feel free to close this issue or keep it in the back burner to see if there'll be interest by others.

[selfhoster1312]

OK so your bot is configured manually outside of matterbridge. If so, why do you need an API at all? Since you need to write a second configuration file for the bot, you could probably reuse that configuration file in your webapp?

[xpufx]

I can. Yes. But other software can decide what to do with discovered existing configuration. For example an app like mine could send the same message to ALL configured destinations.

[selfhoster1312]

I think it could be useful, but for that we need actual identifiers for the room. Your proposed changes reference internal matterbridge config like {"protocol": "slack", "account": "slack.workspace", "channel": "ux"},, so a 3rd party bot would still need custom configuration to know what workspace this channel refers to.

So right now as it is i don't understand how that PR would be useful. I'm not even sure all protocols we support have a URI scheme to reference a specific channel, but maybe we should start there? Like add to all bridges a method which returns a unique URI referencing the target channel from a gateway inout config.

Alternatively, we could simply expose the entire config file from the API. But i'm not very happy about this because we'll leak secrets if your 3rd party API client has security problems.