Getting Started

Now that you have LooperNG installed, we can proceed to start using it. LooperNG can be started in a number of different ways. On a production system, you would normally run LooperNG with a configuration file and let it start up all the modules and the processing. While testing (or debugging), however, the administrative interface is a better way to start it up.

A first run

Before you start LooperNG, make sure the LOOPER_HOME environment variable is correctly set. LooperNG uses this variable to find its libraries and modules.

$ export LOOPER_HOME=/opt/local/looper
$ cd $LOOPER_HOME

To start LooperNG, run the looperng program without any parameters (it doesn't get any simpler).

[looperng@grok looper]$ ./looperng
LooperNG 1.0 running with PID 2524 on grok
Mohit Muthanna (c) 2001

No configuration file supplied.
[Sat Sep 13 10:07:31 2003] [looperng] [0] Starting looper with PID 2524 with loglevel 3
[Sat Sep 13 10:07:31 2003] [looperng] [0] Starting admin server on port 5788

LooperNG is now running and waiting for admin requests on port 5788. For test purposes, let us start LooperNG with debug mode; and listening on a different port.

[looperng@grok looper]$ ./looperng --port 15000 --loglevel 4
LooperNG 1.0 running with PID 2588 on grok
Mohit Muthanna (c) 2001

No configuration file supplied.
[Sat Sep 13 10:18:00 2003] [looperng] [0] Starting looper with PID 2588 with loglevel 4
[Sat Sep 13 10:18:00 2003] [looperng] [0] Starting admin server on port 15000

The --port parameter is used to specify a different port for the admin server. The --loglevel parameter is used to specify a different logging level. The levels are as so:

0 - System
1 - Errors
2 - Warnings
3 - Info
4 - Debug

Connecting to the admin server

Open up another terminal window and telnet to the localhost at the admin port:

$ telnet localhost 15000
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

LooperNG 1.0 running with PID 2588
Listening on grok:15000

ready

The ready prompt means that it is ready to receive data. Type help to receive a list of available commands. Type quit to exit the session.

Authentication

Most of the commands availabe on the admin server are privelaged. To use them, you will have to authenticate the session with the server. To authenticate, use the auth command followed by the password. If you have just installed LooperNG, the default password is 'buggeroff'.

auth
Syntax: auth [password]

Session not authenticated.
auth buggeroff
Password Accepted.

You may want to change the default password for most LooperNG sessions. The password basically an MD5 hashed hexadecimal string. To generate a new password, run looperng with the --md5 parameter.

$ ./looperng --md5 fatbastard
LooperNG 1.0 running with PID 2603 on grok
Mohit Muthanna (c) 2001

No configuration file supplied.
MD5 encrypted password: 4d5d3039def79621969b9c04527dfe39

To start LooperNG with this new password, type:

$ ./looperng --port 15000 --loglevel 4 --password 4d5d3039def79621969b9c04527dfe39

The password can also be set in the LooperNG configuration file (which we'll look at later).

Security Note

Of course, it's not a good idea to keep the admin server running in a production environment. To toggle the status of the admin server, send the LooperNG process a SIGUSR1. The server is enabled by default. To disable it on startup, start looper up with the --disable-admin switch. Assuming LooperNG is running with PID 26003, the following command will disable the admin server:

$ kill -USR1 26003

Running the above command again will enable the admin server.

Proceed to Basic Interface Commands

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