Table of Contents

Set up the discovery tool avahi under an LXC container

Goal

Install the discovery tool avahi directly on the router. With the help of the LXC Container function, the avahi tool can be used on the router to display the FMS data with itxpt.

Prerequisites

1. Set up the LXC Contianer

Activate the LXC container on the router

In the second step the image of the LXC container in this case Debian.

The easiest way to do this is to install the whole thing over the Internet. However, the router requires a mobile connection to the Internet.

From a Jenkins server you get the current image for the container

* Jenkins Server Page / Link

The “armhf” tab is important here

Here you can get a Debina image for buster, bullseye or bookworm.

If you click on the circle with the green rakes, you will be taken to the software. What else is important is that the circle and rakes must be green.

The image is the “rootfs.tar.xz” which is required. With a right click you can copy the link.

It would be structured like this:

https://jenkins.linuxcontainers.org/view/Images/job/image-debian/architecture=armhf,release=bookworm,variant=default/lastSuccessfulBuild/artifact/rootfs.tar.xz

When the “Apply” button is pressed, Debian will be installed.

2. Test LXC installation and set up further

Under the console you can first check whether the installation has been carried out.

USER
~ $ cd /mnt/storage0/lxc/guest0 /mnt/storage0/lxc/guest0 $ ls bin dev home media opt root sbin sys usr boot etc lib mnt proc run srv tmp var /mnt/storage0/lxc/guest0 $

This file must be available under this directory structur

USER
~ $ lxc-info guest0 Name: guest0 State: RUNNING PID: 20493 CPU use: 1.49 seconds BlkIO use: 20.00 KiB Memory use: 7.22 MiB KMem use: 1.20 MiB ~ $

The LXC container is set up and already started.

Set up the LXC container further. A network interface is enabled here.

The container has now also been assigned an IP address.

USER
~ $ lxc-info guest0 Name: guest0 State: RUNNING PID: 2255 IP: 192.168.1.149 CPU use: 1.57 seconds BlkIO use: 4.00 KiB Memory use: 6.29 MiB KMem use: 1.18 MiB Link: virt0 TX bytes: 2.28 KiB RX bytes: 853 bytes Total bytes: 3.11 KiB ~ $

Always assign a fixed IP address for the LXC container via the DHCP server.

Log in to the LXC container and test whether it can access the Internet.

USER
~ $ lxc-attach guest0 root@LXCNAME:~# ping heise.de PING heise.de (193.99.144.80) 56(84) bytes of data. 64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=1 ttl=244 time=42.4 ms 64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=2 ttl=244 time=31.0 ms 64 bytes from redirector.heise.de (193.99.144.80): icmp_seq=3 ttl=244 time=27.1 ms — heise.de ping statistics — 3 packets transmitted, 3 received, 0% packet loss, time 2005ms rtt min/avg/max/mdev = 27.116/33.504/42.432/6.505 ms root@LXCNAME:~#

The container is installed and set up. Now you can set up further tools on the container.

3. Set up the avahi tool

If you have logged in to the LXC container with the command.

$ lxc-attach guest0
root@LXCNAME:~#

You can install the avahi-utils via the packe manager apt-get.

root@LXCNAME:~# apt-get install avahi-utils

You can use the avahi tool completely under the console.

The avahi-browse program will display the multicast DNS addresses on the router.

USER
root@LXCNAME:~# avahi-browse -a + eth0 IPv4 NB2800 SSH Remote Terminal local + eth0 IPv4 NB2800_00112B022DD1._inventory _itxpt_http._tcp local + eth0 IPv4 NB2800_00112B022DD1._fmstoip-rem _itxpt_http._tcp local + eth0 IPv4 NB2800_00112B022DD1._fmstoip-get _itxpt_http._tcp local + eth0 IPv4 NB2800_00112B022DD1._fmstoip-add _itxpt_http._tcp local + eth0 IPv4 NB2800_00112B022DD1._time _sntp._udp local + eth0 IPv4 NB2800_00112B022DD1._gnss_location _itxpt_multicast._udp local + eth0 IPv4 NB2800_00112B022DD1._fmstoip _itxpt_multicast._udp local + eth0 IPv4 NB2800 SFTP File Transfer local

The -r option resolves the name _itxpt_multicast._udp to an IP.

USER
root@LXCNAME:~# avahi-browse -r _itxpt_multicast._udp + eth0 IPv4 NB2800_00112B022DD1._gnss_location _itxpt_multicast._udp local + eth0 IPv4 NB2800_00112B022DD1._fmstoip _itxpt_multicast._udp local = eth0 IPv4 NB2800_00112B022DD1._gnss_location _itxpt_multicast._udp local hostname = [NB2800.local] address = [192.168.1.1] port = [14005] txt = [“multicast=239.255.42.21” “version=1” “txtversion=1”] = eth0 IPv4 NB2800_00112B022DD1._fmstoip _itxpt_multicast._udp local hostname = [NB2800.local] address = [192.168.1.1] port = [15015] txt = [“multicast=239.255.42.21” “version=1” “txtversion=1”]

A service program mreceive is also required for receiving multicast traffic.

4. Set up the mreceive tool

Additional programs are required for the installation of the mreceive utility program.

USER
root@LXCNAME:~# apt-get install git root@LXCNAME:~# git clone https://github.com/troglobit/mtool root@LXCNAME:~# cd mtools/ root@LXCNAME:~/mtools# apt-get install make root@LXCNAME:~/mtools# apt-get install gcc

Once you have completed this preparation, you can execute the mreceive utility program with the “make” command.

USER
root@LXCNAME:~/mtools# make

CC msend.o LINK msend CC mreceive.o LINK mreceive

root@LXCNAME:~/mtools#

Now you only have to change the file on the right and you can use the utility program.

root@LXCNAME:~/mtools# chmod 775 mreceive

To test the mreceive utility program, I have the GNSS multicast traffic output as an XML frame.

root@LXCNAME:~/mtools# ./mreceive -g 239.255.42.21 -p 14005
Now receiving from multicast group: 239.255.42.21
Receive msg 1 from 192.168.1.1:60913: <?xml version="1.0"?><GNSSLocationDelivery
version="1.1a"><GNSSLocation><Data>$GNGNS,,,,,,NN,,,,,,*53$GPVTG,,T,,M,,N,,K,N*2C$GP
GSA,A,1,,,,,,,,,,,,,,,*1E$GNGSA,A,1,,,,,,,,,,,,,,,*00$GPGGA,,,,,,0,,,,,,,,*66$GPRMC,,V,,,,,,,,,,N*53</
Data><Latitude><Degree>0</Degree><Direction>N</Direction></
Latitude><Longitude><Degree>0</Degree><Direction>E</Direction></
Longitude><Altitude>0</Altitude><Time>15:18:45</Time><Date>2024-06-10</
Date><SpeedOverGround>0</SpeedOverGround><SignalQuality>NotValid</
SignalQuality><NumberOfSatellites>1</
NumberOfSatellites><HorizontalDilutionOfPrecision>0</
HorizontalDilutionOfPrecision><VerticalDilutionOfPrecision>0</
VerticalDilutionOfPrecision><TrackDegreeTrue>0</
TrackDegreeTrue><GNSSType>MixedGNSSTypes</
GNSSType><GNSSCoordinateSystem>WGS84</GNSSCoordinateSystem></GNSSLocation></
GNSSLocationDelivery>

* How to set up the FMStoIP