Opening port for remote access to gpsd

[Stein, S. Joshua]

I have an application wherein a GPS unit is attached to a Raspian machine. I have gpsd running and receiving info from the GPS on /dev/ttyUSB0. Connection to the daemon works fine on localhost.

 

I would like to connect to that same daemon from a remote machine using the HOST kwarg when instantiating the gps object. As it stands now, this will fail since the daemon is set up to only listen to localhost.

 

So I change the arguments which fire off gpsd and add the ‘-G’ flag. Upon reboot, I see that gpsd has been invoked properly:

 

● gpsd.service - GPS (Global Positioning System) Daemon

   Loaded: loaded (/lib/systemd/system/gpsd.service; enabled; vendor preset: enabled)

   Active: active (running) since Wed 2020-07-22 09:12:09 CDT; 12min ago

  Process: 323 ExecStart=/usr/sbin/gpsd $GPSD_OPTIONS $DEVICES (code=exited, status=0/SUCCESS)

Main PID: 345 (gpsd)

    Tasks: 1 (limit: 2200)

   Memory: 1.2M

   CGroup: /system.slice/gpsd.service

           └─345 /usr/sbin/gpsd -G /dev/ttyUSB0

 

However when I attempt to connect remotely, I am prevented from doing so (ConnectionRefusedError).

 

If I kill the daemon process (gpsd.socket and gpsd.service) and then invoke gpsd from the command line with:

>gpsd –G \dev\ttyUSB0

 

I am able to connect remotely just fine. So it appears the issue is with how systemd (systemctl) is firing off the daemon

 

I then tried changing the SocketMode parameter within the gpsd.socket file from:

 

SocketMode=0600

To

SocketMode=0666

And eventually to

SocketMode=0777

 

Neither of those made any difference.

 

I realize this issue is likely one of my incomplete understanding of the systemd/systemctl process for handling sockets – but my hope in posting here is that someone else has encountered this issue and can point me to the “AHA!” moment.

 

 

 

Samuel Joshua Stein (Josh) – Research Engineer

Argonne Special Projects - Material Science Division

Argonne National Laboratory

9700 S. Cass Ave, Argonne IL  60439

(630) 252-4105