Addition of last-will options in bridge settings

[peppo65]

Proposal: in the bridge connection settings it could be useful the possibility to configure last-will related options. Something like the following:

• lastwill [true|false] which defaults to false
• lastwill_topic [topic] mandatory if lastwill is true
• lastwill_retain [true|false] which defaults to false
• lastwill_message [string]
• lastwill_payload [path_to_file_containing_payload]

The last two options are mutually exclusive, and one of them must be present if lastwill is true. The first one allows to specify a textual payload directly in mosquitto.conf; the second is for specify a non-textual payload in an external file.

[ralight]

I'm sure you're aware already, but there is a bit of this in the form of the bridge notification topics. Adding your suggestion would mean that a user would have to choose between notifications or not.

It's certainly worth looking at though.

[ksheurs]

Hi there, I am just looking into the bridge notifications configuration now. Are $SYS topics sent both to the bridge's upstream connection as well as clients that are connected to the bridge?

I'm interesting in both the upstream connection getting a LWT-like message + devices connected to the bridge getting notified that the bridge has lost it's connection.