Linux & Library – Web Kiosks for Peanuts Sam Deeljore Pius XII Memorial/HSC Libraries Saint Louis University LITA 2004 National Forum St. Louis, Missouri

Introduction ➲ Library needs ➲ Replace aging text terminals ➲ Provide web access to library catalogs in a simplified kiosk interface ➲ Problems ➲ Lack of funds for new computer equipment ➲ Windows is high maintenance ➲ The Windows desktop UI is hard to control ➲ Modern Windows requires powerful hardware ➲ Linux provides the solution

Why Linux? ➲ No licensing costs ➲ Stability matches or exceeds Windows ➲ Good support for and better performance on older PC hardware ➲ The desktop is easy to control and customize ➲ Solutions for thin clients are readily available ➲ Older hardware can be put back in service

Linux Thin Clients ➲ All the advantages of linux plus centralized management ➲ Applications run on the server and the display is sent over the network to the thin clients ➲ Because the applications run on the server, they run with all the speed of the server ➲ Hard disks which are prone to failure are eliminated with thin clients

Overview of our linux system ➲ Linux Terminal Server Project (LTSP) software ➲ 1 server ➲ 1.2 Ghz Pentium III with 1024 MB RAM ➲ Holds all software including the terminals' OS ➲ System load rarely exceeds 10%, 500MB RAM used, no swapping ➲ 10 public web terminals ➲ 166 Mhz Pentium I with 32 MB RAM ➲ Terminals are diskless – no hard disk, no floppy ➲ Terminals require a special chip for their network cards to facilitate booting.

The Server Software ➲ Linux Terminal Server Project (LTSP) ➲ ➲ Packaged for most major Linux distributions ➲ Open source ➲ Provides the thin-client OS ➲ A stripped down version of linux ➲ Busybox software provides all the command line tools usually found in linux ➲ Xfree86 – X windows system

The Chip That Makes It Happen ➲ The Boot ROM is inserted into a socket on the ethernet card ➲ Chips can be obtained from from ➲ Uses Etherboot open source software, available at ➲ A floppy loaded with etherboot can perform the same tasks as the chip ➲ Prices for the chip are $15-$18 depending on your NIC model

Etherboot – What the ROM does ➲ When machine boots, etherboot is loaded by the BIOS before any device in the boot order ➲ Etherboot requests an IP address, server IP and filename from the DHCP server ➲ Etherboot retrieves the file (the client's linux kernel) using tftp ➲ Etherboot boots the kernel it retrieved

The Web Browser ➲ Opera 7 for linux ( ➲ Advantages ➲ Loads quickly, renders quickly ➲ High-quality standards compliant rendering ➲ Has an excellent kiosk mode ➲ Disadvantage: Must buy a license to make the banner ads go away

Opera Kiosk Mode ➲ Invoked by launching browser with certain arguments as the Shell ➲ Administrator can specify an idle time after which the cache is emptied, history is cleared, and the home page is reloaded ➲ Administrator can hide print, save, and exit menu choices ➲ Administrator can lock browser in fullscreen mode ➲ See

Getting Started ➲ Install your favorite linux on your server (we use RedHat 9.0) ➲ The following server packages are needed: tftp, dhcpd, and nfs. ➲ XDM, KDM, or GDM are needed. We use gdm. ➲ Squid may be installed as a proxy server to accelerate web browsing and/or to restrict kiosks to certain websites, such as your library catalog. ➲ XFS (the Xwindow font server) may be installed so that your server and your clients can share fonts from a single directory (recommended)

Install the Software ➲ Install the LTSP packages ➲ Install boot ROMs on your clients ethernet cards, record the MAC addresses of each of your client's ethernet card ➲ Create/modify the following files: /etc/dhcpd.conf - for dhcp requirements ➲ /etc/hosts- for access to the server ➲ /opt/ltsp/i386/etc/lts.conf - for client configuration

DHCP configuration ➲ Reserve an IP for each of your clients based on their MAC. Additional parameters that must be present for each client are hostname, filename, and root-path. ➲ If a dhcp server is already in place on the network, it can be used with minor modifications ➲ Be very careful with DHCP

Configuring the Clients ➲ Basic settings are all done in the file /opt/ltsp/i386/etc/lts.conf ➲ Default setting applies to all hosts not specifically defined ➲ Set client runlevel, turn swap file on/off, set size, choose custom X server settings ➲ When a client boots it reads lts.conf and dynamically creates all the configuration files a linux machine needs (in temporary storage in client RAM)

Linux Runlevels in LTSP ➲ Runlevel 3: for debugging – clients boots and the user gets a shell as root ➲ Runlevel 4: telnet to a host in a loop with no exit– set the telnet host to connect to in lts.conf ➲ Runlevel 5: graphical login, display is managed by the server

Desktop Security ➲ Opera kiosk mode ➲ Disable unwanted XDMCP sessions ➲ Enable timed login and autologin ➲ Disable remote root login

Network Security ➲ Firewall: iptables ➲ Tripewire Intrusion Detection System ➲ TCP Wrappers ➲ Keep current with patches

Beyond Web Kiosks ➲ Ideal desktop replacement for departments which are not dependent on Windows desktop or Windows only applications. ➲ What can users do on UNIX/LINUX? ➲ (Web Mail or Pop3/Imap) ➲ Open Office/Star Office (MS office clones) ➲ Web applications and telnet and ssh sessions ➲ UNIX software development ➲ Many users on one powerful server means more efficient use of CPU cycles than many users on many new powerful desktops.