Support custom pool keys

[maxsalven]

I have an app that sends Apple Push Notifications on behalf of multiple different developer accounts.

Apple's APNs server requires any given connection to be used exclusively by a single developer's authentication tokens.

https://developer.apple.com/documentation/usernotifications/establishing-a-token-based-connection-to-apns

APNs doesn’t support authentication tokens from multiple developer accounts over a single connection.

You can’t map a connection to APNs to multiple teams. If you manage APNs for multiple developer accounts, open separate connection pools for each of them.

As part of the authentication process, APNs relates a team ID and associated bundle IDs to a connection on the first push. After the authentication process, attempting to associate a different team or sending a push to a newly added bundle ID causes an error. To send remote notifications to a new topic, add the topic to your team in App Store Connect and create new connections to APNs.

Hence I can't use the URL schema as the pool identifier with Finch, I need a way to manually associate a connection pool with a team (developer account) ID. Essentially I need multiple separate pools which happen to connect to the same URL.

Note that this is exclusively for HTTP2.

Is this something that could conceivably be supported in Finch?

[sneako]

Good point, I'm surprised this issue hadn't been raised earlier.

It should be quite trivial to add an optional pool alias option.

As a temporary workaround, you could consider starting separate Finch instances for each separate account, but this new alias option sounds like a reasonable feature.