Syslog-ng server on Ubuntu

Well once you know what to do it is actually easy to get it going, however there is a few things you need to know:

• Remote logging needs to be enabled on the server


• Firewall needs to accept traffic for syslogs


• on the client logs need to be forwarded to the syslog server


• a log filter need to be created on the client

So a typical / basic setup that forwards everything to the servers default log destinations e.g. /var/log/syslog will look as follows:

Server side:
Basic config change to get the server accepting remote logs:
uncomment:
         udp();
Client side:
The most basic setup to forward all logs to the syslog-ng server:

destination server { udp("192.168.0.1" port (514)); };

log {
        source(s_all);
        destination(server);
};

I am also sending logs from my Mikrotik device to the syslog-ng server as follows:

[user@Mikrotik] > /system logging action print
Flags: * - default
 #   NAME                      TARGET REMOTE                                  
 0 * memory                    memory
 1 * disk                      disk 
 2 * echo                      echo 
 3 * remote                    remote 192.168.0.1:514                           
[user@Mikrotik] >

[user@Mikrotik] > /system logging print       
Flags: X - disabled, I - invalid
 #   TOPICS                          ACTION                          PREFIX   
 0   info                            memory                                   
 1   error                           memory                                   
 2   warning                         memory                                   
 3   critical                        echo                                     
 4   warning                         remote                          mikrotik

Happy logging.

To test if a port is open on linux

Well I wanted to test if a linux box is ready to receive syslog log files remotely and used netcat / ccat / nc for the purpose.

It is a server/client application whereby you run the server in listen mode and then start the client on a different host and connect to the server, it can create both tcp and udp connections.

I had some trouble with the syntax on Ubuntu 10.04 Lucid Lynx and hence will post the commands that worked for me:

Server:

user@server:~$ sudo nc -l -u 514

-l : is for listen
-u : is for udp

Client:

user@client:~$ nc 192.168.0.1 -u 514

where 192.168.0.1 is the ip of the server
If it connects you can then type anything in the client and it will display in the server window confirming the port is available and no firewall is blocking teh traffic, hence you can move to the application layer.

how to keep program running after closing ssh session

I first tried <command> &  - but that only put the program in the background when disconnecting it terminted the job

I then tried nohup <command> & detaching it supposedly from the terminal but it did not work either

 I then found a program called screen

sudo apt-get install screen 

To start an shell app just type

screen -Amd command

Once it's running, press Ctrl-a (control and a at the same time), then press d

to re-attach to it later, login with ssh and type

screen -r 

MythTV - DSTV Channel Changer

LIRC

So the first step was to get LIRC up and running on Mythbuntu; this was quite easy as the default installation do enable lirc, I only selected " Enable an IR Transmitter" and selected a bogus Serial lirc device.



This created all the relevant configuration files.

I then searched the net for the lircd.conf (remote command reference file) for my spesific decoder

(DSD820 aka DSTV DualView Decoder).

 I did not find the spesific file but found one for the UEC DSD910 decoder.



The DSD910 remote file (general.conf):

#
# this config file was automatically generated
# using WinLIRC 0.6.5 (LIRC 0.6.1pre3) on Wed Sep 10 15:36:20 2003
#
# contributed by Guy Antony Halse <guy-lirc@rucus.ru.ac.za>
#
# brand:             Multichoice
# model:             DSD910
# supported devices: Digital Satellite Decoder (DSTV Decoder)
#
# Multichoice is a South African Satellite TV company offering their
# own branded decoders.

begin remote

  name  dsd910

  bits           13
  flags RC5|CONST_LENGTH
  eps            30
  aeps          100

  one           962   808
  zero          962   808
  plead         992
  gap          113485
  toggle_bit      2
      begin codes
          power                    0x000000000000160C
          red                      0x000000000000162C
          green                    0x000000000000162B
          yellow                   0x000000000000162A
          blue                     0x000000000000162E
          1                        0x0000000000001601
          2                        0x0000000000001602
          3                        0x0000000000001603
          4                        0x0000000000001604
          5                        0x0000000000001605
          6                        0x0000000000001606
          7                        0x0000000000001607
          8                        0x0000000000001608
          9                        0x0000000000001609
          0                        0x0000000000001600
          radio                    0x0000000000001625
          tv                       0x000000000000162F
          mute                     0x000000000000160D
          teletext                 0x0000000000001624
          information              0x000000000000162D
          up                       0x0000000000001612
          left                     0x000000000000161D
          ok                       0x0000000000001622
          right                    0x000000000000161E
          down                     0x0000000000001613
          menu                     0x000000000000161C
          exit                     0x0000000000001631
          tvguide                  0x0000000000001635
          progup                   0x0000000000001620
          progdn                   0x0000000000001621
          volup                    0x0000000000001610
          voldn                    0x0000000000001611
      end codes

end remote
 

This file was copied to the relevant directory in /var/lib/cache/lirc/....

The next step was to change the config in /etc/lirc/hardware.conf

#Chosen IR Transmitter
TRANSMITTER="dsd910"
TRANSMITTER_MODULES="lirc_dev lirc_serial"
TRANSMITTER_DRIVER=""
TRANSMITTER_DEVICE="/dev/lirc0"
TRANSMITTER_LIRCD_CONF="dsd910/general.conf"
TRANSMITTER_LIRCD_ARGS=""

After that I started the lirc again:

sudo /etc/init.d/lirc start

This was then tested with the following command:

sudo irsend SEND_ONCE dsd910 information

This worked and showed the "information banner".
This was tested on TV1.

Still to do is to  add and test TV2 ir and to enable a change channel script in Mythbuntu.

Bind Dynamic DNS Updates

I saw a request to update Bind via a command line rather than Webmin for the ease and speed of a command line; So I embarked on investigating this.

Firstly it seems that there is not a lot of dynamic update or command line update scripts available or the people just don't want to share ???

I stumbled across nsupdate, an application that is part of the Bind suite.
This is a command line tool to add dynamic updates to an DNS server.

for this to work you need to update the specific zone file with at least the following configuration:

zone "example.com" {
type master;
file "/etc/bind/example.com.hosts";
allow-update {192.168.0.0/24; };
journal "/var/lib/bind/example.com.hosts.jnl";
};
For dynamic DNS you need:
allow-update
journal

then to add an entry to the DNS server:
from within the 192.168 ip range :

user@pc:~$ nsupdate
> zone example.com
> update add guest1.example.com. 86400 A 192.168.0.10
> send
> quit

your syslog on your DNS server will log all updates