piaware-status: False negatives when in unprivileged docker container

[rfinnie]

When running in an unprivileged Docker container, everything functionally works fine as long as the proper USB device is passed in, but piaware-status reports:

root@98cec28c1d21:/# piaware-status 
PiAware master process (piaware) is running with pid 52.
PiAware ADS-B client (faup1090) is running with pid 90.
PiAware mlat client (fa-mlat-client) is running with pid 92.
Local ADS-B receiver (dump1090-fa) is running with pid 69.

unknown process (pid unknown) is listening for connections on port 30005.
faup1090 is NOT connected to the ADS-B receiver.
piaware is NOT connected to FlightAware.

dump1090 is producing data on localhost:30005.

Your feeder ID is [UUID] (configured at /etc/piaware.conf:9)

This is because socket to PID mappings aren't available:

root@98cec28c1d21:/# netstat --program --tcp --wide --all --numeric
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:8080            0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:30002           0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:30003           0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:30004           0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:30005           0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:30104           0.0.0.0:*               LISTEN      -                   
tcp        0      0 172.17.0.2:30002        172.17.0.1:55756        ESTABLISHED -                   
tcp        0      0 172.17.0.2:39529        70.42.6.198:1200        ESTABLISHED -                   
tcp        0      0 172.17.0.2:8080         10.9.8.4:59512          TIME_WAIT   -                   
tcp        0      0 127.0.0.1:46626         127.0.0.1:30005         ESTABLISHED -                   
tcp        0      0 127.0.0.1:55802         127.0.0.1:30104         ESTABLISHED -                   
tcp        0      0 127.0.0.1:30104         127.0.0.1:55802         ESTABLISHED -                   
tcp        0      0 172.17.0.2:8080         10.9.8.4:59504          TIME_WAIT   -                   
tcp        0      0 127.0.0.1:30005         127.0.0.1:46736         ESTABLISHED -                   
tcp        0      0 172.17.0.2:30005        172.17.0.1:39564        ESTABLISHED -                   
tcp        0      0 127.0.0.1:30005         127.0.0.1:46626         ESTABLISHED -                   
tcp        0      0 127.0.0.1:46736         127.0.0.1:30005         ESTABLISHED -                   
tcp        0      0 172.17.0.2:8080         10.9.8.4:59498          TIME_WAIT   -                   
tcp6       0      0 :::30002                :::*                    LISTEN      -                   
tcp6       0      0 :::30003                :::*                    LISTEN      -                   
tcp6       0      0 :::30004                :::*                    LISTEN      -                   
tcp6       0      0 :::30005                :::*                    LISTEN      -                   
tcp6       0      0 :::30104                :::*                    LISTEN      -                   
tcp6       0      0 :::30105                :::*                    LISTEN      -                   
tcp6       0      0 :::30106                :::*                    LISTEN      -                   

piaware-status should probably check for this situation; e.g. ":1200" and program "-" should report something like "piaware is probably connected to FlightAware, but cannot be certain due to environment restrictions." instead of "piaware is NOT connected to FlightAware."

[mutability]

I'm not sure that it's expected that piaware-status will work in a docker environment