Exposing clients and IP address

[mattkrick]

Story

• As a uWS server, I want to capture the IP address of the connected user for logging. This could be accomplished by e.g. if the return value of behavior.upgrade could get injected into the UpgradeData.

• As a developer, when I deploy a new version of my server I send a SIGTERM to the old servers. At that time, I would like to gracefully tell each connected client to disconnect over the course of the next 30 seconds so they automatically reconnect to a new server. This requires iterating over a list of all connected clients. Exposing that Map on the return value of makeBehavior would allow me to do that without creating a duplicate object. Alternatively, makeBehavior could accept a clients Map in the options.

[enisdenjo]

Adding the upgrade data to the context should not be a big deal. You're even welcome to open a PR!

Regarding the second point, you can always have an array of connected sockets on the outside and simply push the socket in onSubscribe and pop it out in onClose. After receiving the SIGTERM, just iterate over that map and send whatever you wish. Am I understanding the issue correctly?

[toini]

We implemented this (and later switched to uWs) to tackle the item 2. See #489