Create multiple LXM Routers with different identities

[r8io]

Question

How do I create multiple LXM Routers with different identities in a single application. My goal is to provide multiple LXMF destinations, created from different identities, for interaction with an application.

My naive approach

My naive approach looks like this (simplified):

 message_router1 = LXMF.LXMRouter(identity1, storagepath1)
 message_router2 = LXMF.LXMRouter(identity2, storagepath2)

Which produces the following error:

Attempt to register an already registered destination.

Versions used: rns 0.7.7, lxmf 0.5.0

Disclaimer

I do not know anything about LXMF besides the examples Mark provided. My naive "solution" at the end is most likely not a good solution since I clearly wander in forbidden land here. I do not even know what a lxmf.query destination is used for :-)

There probably is a much more adequate way to go about this problem without the "need" to change RNS source code.

Problem

It appears that every LXM Router creates three destinations:

• lxmf.query
• lxmf.propagation
• lxmf.delivery

The lxmf.query destination is created WITHOUT an identity, which results in the creation of identical lxmf.query destinations even if LXM Routers are created with different identities. This leads to the Attempt to register an already registered destination error mentioned above.

LXMF.LXMRouter.py (line: 120):

self.lxmf_query_destination  = RNS.Destination(None, RNS.Destination.IN, RNS.Destination.PLAIN, APP_NAME, "query")

My naive "Solution"

The original code prevents the registration of existing destinations by raising an error. This prevents the creation of multiple LXM Routers, at least in the way I go about it as explained above.

RNS.Transport.py (line 1948):

def register_destination(destination):
    destination.MTU = RNS.Reticulum.MTU
    if destination.direction == RNS.Destination.IN:
        for registered_destination in Transport.destinations:
            if destination.hash == registered_destination.hash:
                raise KeyError("Attempt to register an already registered destination.")

        Transport.destinations.append(destination)

        if Transport.owner.is_connected_to_shared_instance:
            if destination.type == RNS.Destination.SINGLE:
                destination.announce(path_response=True)

My naive "solution" prevents the registration of existing destinations by skipping. By doing so I can create multiple LXM Routers, but only ONE lxmf.query destination is created. On a superficial level that seems to work, but considering my disclaimer above the validity of this approach should be questioned ;-)

def register_destination(destination):
        destination.MTU = RNS.Reticulum.MTU
        if destination.direction == RNS.Destination.IN:
            destination_exists = False
            for registered_destination in Transport.destinations:
                if destination.hash == registered_destination.hash:
                    # raise KeyError(f"RNS.Transport() Attempt to register an already registered destination. {destination}")  # r8io
                    destination_exists = True
                    RNS.log(f"RNS.Transport() Attempt to register an already registered destination. {destination}", level=2)
                    continue

            if not destination_exists:
                Transport.destinations.append(destination)
                RNS.log(f"RNS.Transport() Registered destination. {destination}")

                if Transport.owner.is_connected_to_shared_instance:
                    if destination.type == RNS.Destination.SINGLE:
                        destination.announce(path_response=True)

[markqvist]

Thanks for your detailed post about this! Fortunately, the real fix is very easy. The query_destination is a very old artifact on a very old version of LXMF, and it has not been used for anything for about three years. The fix is to remove it, as I have just done in commit this commit.

Thanks for spotting and investigating it!

You should be able to pull the latest source from the repo and do as you want now :)

[r8io]

Thank you for for your quick reply and the easy fix! I feel like the blind hen that found a kernel of grain ... relay happy :-) It works nicely now.