Tacatá

Tacatá is a lightweight Python script which creates Netkit and Kathará labs using an enriched version of the lab.conf file with a simple syntax.

You can find some examples of lab.confu configuration files in labs folder.

!!! WARNING !!!

Keep in mind that Tacatá is only intended to be used during Intermediate Tests for the Infrastructures of Computer Networks course at the Roma Tre University. We're not trying to support all the Kathará features (like P4 programming or NFV approaches). However, you can still create all the files/folders manually in the generated lab.

How it works

Create a lab.confu in the directory where tacata.py is stored.
Write all you need to reproduce the lab in the lab.confu file.
From a Terminal, launch python tacata.py.
The generated lab will be placed in a new lab folder
You can normally launch the lab from the lab folder without extra steps!

Currently Supported

Terminals/Routers
Web Servers (with autogenerated index.html file in /var/www/html & Apache Mods support)
Load Balancer Templates (with ONLY support for nth and random modes)
DNS and Named Hosts (currently, only master mode is supported) - Local NS (for hosts)

Syntax

All the configuration is based on function calls which affect the current device and/or the current interface unless otherwise specified. The current device and the current interface are those defined in the line in which the function is called. For example in the configuration line

pc[0]=A

the current device is pc. while the current interface is eth0.

Each line is composed of two parts separated by the special character $. The first part of the line is a standard netkit/Kathará device definition whereas the second part is a sequence of commands separated by ;.

Interface Configuration

Setting ip addresses

To set the ip address of the current interface the ip function is used. This function expects a single parameter which is the ip address to set along with the length of the netmask.

For example, the following line assigns the ip address 1.0.0.2/24 to the eth0 interface of pc.

pc[0]=A     $ip(1.0.0.2/24);

Gateways

You can set the gateway towards a certain lan with the command to. The command to is always referred to the output interface used to reach that lan.

For example, if all the packets towards the lan 1.2.0.0/24 should be forwarded to 1.1.0.2 through the interface eth1 of r1 the following line should be used

r1[1]=B     $ip(1.1.0.1/24); to(1.2.0.0/24, 1.1.0.2);

As it is possible to see to expects two parameters. The first is the lan to reach, while the second is the gateway to use to reach that lan.

In order to set the default gateway for a certain interface, default can be used in place of a lan ip.

pc[0]=A     $ip(1.0.0.2/24); to(default, 1.0.0.1);

Device Configuration

Load Balancers

To use a specific device as a Load Balancer, the balancer command is used. The function expects at least four parameters: the name of the device that we want to use as Load Balancer, the balancing mode (nth or random), the interface used to receive packets, device names and interfaces of the "balanced" devices (the ones "behind" the Load Balancer).

As an example:

            /------eth0---WEB1
---eth1---LB
            \------eth0---WEB2

The LB device acts as Load Balancer for WEB1 and WEB2 devices. It is configured as follows:

LB[0]=C     $ip(10.0.0.1/24);
LB[1]=B     $ip(1.2.0.3/24); to(default, 1.2.0.1);
$balancer(LB, nth, eth1, WEB1|eth0, WEB2|eth0);

Keep in mind that the generated configuration is only a template and you must complete it replacing placeholdes inside iptables commands inside .startup file.

Web Servers

To configure a device as a Web Server, the webserver command is used. It takes at least a parameter (the device name) and other optional parameters which are the names of the apache2 mods to activate on startup.

Using the example from the previous section, we want to configure WEB1 as a webserver running apache2 with rewrite mod activated.

WEB1[0]=C     $ip(10.0.0.3/24); to(default, 10.0.0.1);
$webserver(WEB1, rewrite);

An autogenerated index.html file is placed into /var/www/html and contains the device name of the webserver.

damiano-massarelli/Tacata