Novell SLRS 8 - Manual

Red-Paper: POS/Retail Project
SUSE LINUX Retail Solution 8
(SLRS 8)
Admin Guide
F. Balzer, S. Duehr, T. Franke, R. Oertel,
G. Rieger, M. Schaefer, A. Schmidt
SUSE LINUX AG, Nuernberg
May 3, 2006
Revision: 1275

Contents
1 Introduction 7
2 Architectural Overview 9
2.1 Administration Server ....................... 9
2.2 Branch Server ............................ 14
2.3 Cash Register ............................ 16
3 Quick Start Guide 21
3.1 Installation Process ......................... 22
3.2 Installation of the Administration Server ............. 23
3.3 Installation of the Branch Server ................. 31
3.4 Test your SLRS System Environment ............... 38
4 Server Structure 43
4.1 Requirements ............................ 43
4.2 Architecture ............................. 44
4.3 LDAP Structure ........................... 44
4.4 Server Configuration and Server Services ............. 47
4.5 POS Scripts ............................. 48
4.6 Cash Register Images ........................ 50
5 Setting up Administration and Branch Servers 55
5.1 Installation of the Administration Server ............. 55
5.2 Installation of the Branch Server ................. 61
5.3 Installation of the Highly Available Branch Servers ....... 65
6 Server Commands 71
6.1 posInitLdap.sh .......................... 72
6.2 posInitBranchserver.sh ..................... 73
6.3 possyncimages.pl ......................... 74
6.4 posldap2crconfig.pl ....................... 75
6.5 posleases2ldap.pl ........................ 75
6.6 posldap2dns.pl .......................... 76
6.7 posldap2dhcp.pl .......................... 77
6.8 posReadPassword.pl ........................ 77
6.9 poscheckip.pl ........................... 78
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Contents
7 PosAdmin 79
7.1 Basic Command Line Options ................... 79
7.2 Basic Actions ............................ 80
7.3 Managing Hardware ........................ 92
7.4 Managing Images .......................... 95
8 The imageBuilder 99
8.1 Overview of the POS_Image Packages ............... 99
8.2 Operating System Images .....................101
8.3 Installing imageBuilder .......................101
8.4 Copying the SLRS CDs into a Central Archive ..........102
8.5 Configuring the imageBuilder ...................102
8.6 Prebuilt Standard Images .....................103
9 The Boot Process of a Cash Register System 105
10 The scr tool 107
11 Creating Operating System Images 111
11.1 List All Image Descriptions .....................112
11.2 Creating a Standard Image .....................112
11.3 Creating a New Image Description Tree ..............113
11.4 Extending an Image ........................117
11.5 Manually Extending an Image ...................119
11.6 Configuring an Image .......................120
11.7 Distributing New Images ......................123
12 Preparing a CD-ROM Boot Image 125
12.1 Preparing the CR CD-ROM Boot Image ..............125
12.2 Creating the CD ISO Image ....................128
12.3 Booting the CR CD-ROM Boot Image ...............129
13 Automatic Branch Server Installation 131
13.1 Server Preparation .........................131
13.2 LDAP Data for the Branch Server .................132
13.3 XML Template File .........................133
13.4 Tools .................................134
13.5 Creating the Boot Media ......................135
14 Best Practices 137
14.1 Backup and Restore .........................137
14.2 Access Control ...........................139
15 Advanced Topics 141
15.1 Operating System and Boot Image Details ............141
15.2 Standard Images ..........................142
15.3 Boot Images .............................142
15.4 Naming and Storing Images ....................143
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Contents
15.5 Creating Images ...........................144
15.6 Booting the Cash Registers .....................146
15.7 Thin Client Adminstration .....................154
16 Troubleshooting 157
16.1 Server Infrastructure ........................157
16.2 Operating ..............................159
A Installation RPM Lists 163
A.1 RPM Lists for Minimal Installations ................163
A.2 RPM Lists for Default Installations ................164
Index 177
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Contents
6

1 Introduction
The SUSE LINUX Retail Solution 8 (SLRS 8) for Point of Sale (POS) Retail
Systems is based on the SUSE LINUX Enterprise Server 8 (SLES 8) and pro-
vides a complete SUSE LINUX operating system and management solution
for POS Cash Register Systems (CR). The SLRS architecture was designed to
use a central administration server for deployment and management and a
branch server infrastructure in each branch (office) for preinstall or in-store
deployment.
The administration server provides the following features:
•Central LDAP directory to manage POS terminals and servers
•Global and default parameters and application configuration
•POS Image creation and release management
The branch server provides the following features:
•Software transport for OS and application updates
•Multicast boot infrastructure for POS terminals
•Diskless and diskful POS clients
•AutoYaST installation and online update for server OS
•Option: Two-node high availability cluster with replicated data
Because this document comprises conceptual and user information, the fol-
lowing list of topics is provided for the reader:
•Architectural Overview — Chapter 2:The purpose of this chapter is
to provide an overview of the concept of the SLRS and the interaction of
the several components.
•Quick Start Guide — Chapter 3:Best point to start with the SLRS.
•All about Servers — Chapters 4,6, and 7:The topics of these chap-
ters are the server structure, the SLRS LDAP directory service, the POS-
related server commands, and the PosAdmin commands for manipulat-
ing the LDAP directory entries.
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1 Introduction
•Building and Maintaining POS Images — Chapters 8,10,11 and
12 These chapters summarize all information about how to build and
distribute custom POS images.
•Autobuild Branch Server — Chapter 13:Description for SLRS experts
of how to prepare a CD boot media for automatic branch server installa-
tion.
•Maintaining SLRS — A View Inside SLRS — Chapters 14 and 15:
Further expert information for sysadmins can be found in these chapters.
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2 Architectural Overview
Contents
2.1 Administration Server ..................... 9
2.1.1 LDAP Directory ..................... 11
2.1.2 Tools ........................... 11
2.2 Branch Server ......................... 14
2.2.1 Functionality ...................... 14
2.2.2 Operating System .................... 14
2.2.3 Administration ..................... 15
2.2.4 Clustering ........................ 15
2.2.5 Accessing the POS Terminals ............. 15
2.3 Cash Register .......................... 16
2.3.1 Requirements ...................... 16
2.3.2 Operating System .................... 16
2.3.3 SLRS Boot System ................... 17
2.3.4 Boot Process ...................... 18
2.3.5 Graphical Display Configuration ............ 19
2.3.6 Hard Disk Installation ................. 19
2.3.7 CD Boot Installation .................. 19
The SLRS provides a system platform for the cash registers and in-store servers,
a scalable deployment infrastructure, and a centralized management system.
The CRs are implemented in a variety of hardware forms, with the main differ-
ence being whether they are equipped with hard drives (diskless vs. diskful).
Figure 2.1 describes the system architecture: one centralized administration
server (AS) controls a large number of branch servers (BS), which in turn pro-
vide the local infrastructure for the cash register point of sales (POS) systems.
All servers are intended to be set up as highly available two-node failover
cluster systems.
2.1 Administration Server
All system management for BS and POS systems (CR) is done on the central
administration server (AS). It provides the following services:
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2 Architectural Overview
100 MBit Ethernet
Cash Register (CR)
Administrator
Admin Server (AS)
Branch Server (BS)
WAN
100 MBit Ethernet
AS
BS
BS
BS
Router
Router Switch
Figure 2.1: System Architecture of the SUSE LINUX POS/Retail Solution
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2.1 Administration Server
RSYNC: An rsync server is used for software distribution and provides the
POS system images and software updates to the BS systems.
LDAP: The AS is the master LDAP directory server for the BS systems.
XNTP: The BS xntp system can access the AS for time synchronization
SYSLOG: The AS consolidates the syslog output from the BS.
DNS: Name resolution for the local network, branch servers, and stand-alone
POS systems in small branches.
LDAP directory root node
Corporate Entity level
Branch Level (BS)
CR Configuration Entries
Figure 2.2: LDAP Directory Layout for the POS Administration Server
2.1.1 LDAP Directory
The LDAP directory is structured in three tiers. Under the topmost “company
root” node, the different organizational units are listed. Each unit has its
branches with the BS configuration. Each branch has its POS entries. Figure
2.2 describes the directory tree layout. Entity definitions and more detailed
information can be found in Chapter 4.3 on page 44.
2.1.2 Tools
The tools use the LDAP directory for navigation, are stored in /opt/SLES/POS/bin,
and are programmed in Perl using the Net::LDAP module. The following tools
exist on the AS:
POS/BS Management
The posAdmin software (refer to Section 7on page 79), which is part of the
SLRS, provides a tool for managing the POS LDAP structure, the directory
service running on the administration server holding the data of the branch
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2 Architectural Overview
servers, cash registers, and network infrastructure. Using posAdmin, the fol-
lowing POS Data LDAP entries can be managed:
•organizational unit
•branch
•hardware type
•MAC address
•IP address (optional)
•debug mode
•OS Image name
Cash registers can be created, deleted, and assigned specific operating system
images. Additional parameters, like debug mode, can be set.
Using posAdmin the following BS Data LDAP entries can be managed:
•organizational unit
•branch
•IP addresses
•LAN IP network address
•host name
•domain name
•router address
•debug mode
Branches and the corresponding branch servers can be created and deleted.
Parameters, like debug mode, can be set. Each BS has its own password and
LDAP identity for accessing the LDAP directory.
Package Update
Loads updated software packages and configuration tables for the image cre-
ation from the SUSE maintenance servers.
Reports
Simple report generation tools are available that extract data from the LDAP
directory.
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2.1 Administration Server
POS Image Creation
Images are created from SLRS or SLES standard packages and additional Ser-
vice Pack packages using the SLRS imageBuilder software. For more detailed
information, refer to Chaper 8on page 99. Figure 2.3 describes the image
creation process.
Packages
Configuration List
Local Configuration List
boot
CR
Application Image
Application Start cmd
Script
Image
Image
RPM
Figure 2.3: POS Image Creation
Images are created with a time stamp in the file name. Old images are kept on
the server. POS applications are integrated by specifying one or more package
files (RPM or root-relative tarballs) and one start script name. Additional
packages from the SLRS or SLES distribution can be added to the image by
the customer to extend the functionality of the operating system.
For the integration of more complex software, the image building process can
be split into two parts: first the system is set up in a directory on the AS,
second the directory is packaged into the appropriate file system images. The
purpose is that the customer can modify the system between the two steps,
for example, for installing software that needs the runtime environment of the
AS for installation.
Here is a summary of the information needed by the imageBuilder for the
image creation process:
•System RPM: Packages from SLRS, SLES, and Service Packs.
•Image Type: It defines the image functionality and contents (minimal,
java, browser, etc.).
•Machine Type: It describes the machine hardware, necessary driver
modules, and additional scripts.
•Configuration Lists: It describes the standard set of packages and scripts
for the specific image type in its default configuration for the different
hardware types.
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2 Architectural Overview
•Local Package Lists: It defines site and customer–specific packages
from SLRS and SLES that are added to the POS system image.
•Application: Packages and start command.
2.2 Branch Server
The branch server (BS) provides the network boot and system management
infrastructure for the POS systems as well as a generic system platform for in-
store applications, like database systems and back-ends for the cash register
applications.
2.2.1 Functionality
The BS provides the following services:
DHCP: Controls the network boot process.
TFTP: Provides PXE control files, operating system images, and configuration
files.
XNTP: NTP server for time synchronization.
SYSLOG: The logging target for the cash register systems.
SNMP: Standard MIB2 monitoring is set up with net-snmp.
DNS: Name resolution for the local network.
The BS has a software distribution mechanism based on rsync and is able to
pull new POS operating system images from the administration server. Con-
figuration data is taken from an LDAP directory system on the AS. For large
branches, the corresponding LDAP subtree can be replicated to the BS.
2.2.2 Operating System
The BS is built from a standard SLRS or SLES operating system. An AutoY-
aST2 control file is provided for the basic setup, together with detailed doc-
umentation and tools to configure the server easily. If only the functionality
for running the POS infrastructure is necessary (no additional applications),
the branch server can also be deployed as a control terminal running on POS
hardware.
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2.2 Branch Server
2.2.3 Administration
No system administration other than emergency handling is necessary on the
BS. All administrative tasks are controlled from the central AS and are ex-
ecuted regularly by scripts run by the cron scheduler. For emergencies and
debugging, all functionality can be triggered locally or via SSH login by call-
ing scripts with no or few command line parameters. The functionalities are
described in the following sections.
POS CR Setup
Set up all or one single cash register and local service configuration files (PXE
configuration, /etc/syslog.conf, etc.) and image files for the boot process of
the cash registers. The following functions are provided:
•Boot configuration: Create the DHCP entry and PXE configuration file
for cash registers.
•DNS: Create the zone file and configuration file for BIND name server.
•Config Files: Create configuration files for download by the POS sys-
tems.
Image Update
Trigger the rsync update process of downloading new image files from the
administration server.
Software Layering
All SLRS tools for the BS and the AS consist of a high-level script (“call wrap-
per”) that combines defaults, command line parameters, and environment
variables, reads data from LDAP, then calls low-level scripts.
2.2.4 Clustering
The BS systems are two-node heartbeat clusters. The configuration data (dhcp
leases) and application data (cash register application database back-end ta-
bles) is synchronized with DRBD. Software transport “pull” procedures from
the AS run on both cluster nodes.
2.2.5 Accessing the POS Terminals
It is possible to distribute SSH public keys to the authorized_keys files of the
POS terminals root user. By default, no keys are distributed, disabling login to
the POS terminals.
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2 Architectural Overview
2.3 Cash Register
The cash registers (POS) are specialized systems based on an x86 32-bit ar-
chitecture. Some are diskless systems and some have internal hard drives or
other persistent media (flash drive or other) that can be used for application
data or the operating system.
2.3.1 Requirements
The capability to boot from the network via PXE is required for the POS.
2.3.2 Operating System
The operating system is a minimal operating environment for the specialized
POS application. Different functionality level systems exist, from an extremely
small console-based system to a feature-rich java and browser capable system
and a system with a customized desktop environment.
A set of standard prebuilt POS images are provided with the SLRS. The system
images can be created on an administration server by system administrators
using the SLRS imageBuilder to provide new releases of POS images or to
extend the default POS images for new or customized features.
Each POS terminal gets a system image based on the branch in which it is
located and its hardware type or its individual configuration. If no image is
specified for the model type and the individual POS terminal, a global default
image is loaded.
The cash register applications are integrated into the images. Customization
is performed by loading local configuration files into the file systems over the
network during boot time. The actual operating system images contain a set
of common components (specified in the section about the common operating
system base) and additional features for the different requirements of the
applications.
Common Operating System Base
All system images are built from a common operating system base. This plat-
form is created from standard SLRS and SLES packages. The POS system
image contains the following components:
•Kernel modules for hardware, file system, and network support
•GLIBC and STDLIBC++ libraries
•Bash and base file handling utility
•xntp client for time synchronization
•Multicast TFTP capable TFTP client (atftp)
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2.3 Cash Register
Minimal Operating System "Image 1"
The minimal image only contains the runtime environment for native code ap-
plications (e.g., C, C++) and the “ncurses” library for user interface support.
Java-capable Operating System "Image 2"
In addition to the minimal system, the capability to run java programs in a
Java2 runtime environment is provided.
•Java2 JRE with Swing GUI libraries
•X11 server and configuration
Java and Browser–capable System "Image 3"
In addition to the Java system, a web browser (Mozilla) is available. This
image will be available for diskful systems first and may be made available for
diskless and netboot systems later.
Desktop Operating System "Image 4"
A "fat client" system that cannot be booted from the network and contains
a full graphical user interface (KDE or GNOME). This system is available for
diskful systems only.
2.3.3 SLRS Boot System
A special boot system performs the boot process, especially the loading of the
more substantial system and application images. The boot system contains:
•Kernel modules for hardware and network support, cramfs, and file sys-
tem modules
•GLIBC library
•Busybox-based shell environment for scripting and system control
•Multicast TFTP–capable TFTP client (atftp)
•linuxrc script for sytem setup and synchronization
Busybox provides a simple shell, scripting tools (sed, md5sum), kernel module
handling tools, and a syslog daemon. For security and space reasons, no login
capability is provided, neither locally nor over the network.
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2 Architectural Overview
2.3.4 Boot Process
The POS operating system may consist of several images. The file systems
that may be mounted read-only can be stored in cramfs-compressed RAM file
systems to save POS RAM resources. A special CR configuration file, which
contains information like image name and BS IP address for the application,
is loaded from the BS server TFTP directory.
On booting, each cash register performs the following procedure:
1. run model-type
2. look up model type in a table to determine the right network module
3. get IP address and PXE image via DHCP
4. get PXE first stage image via TFTP
5. get PXE config file via TFTP
6. get kernel and initrd via TFTP
7. start kernel, mount initrd, start linuxrc
8. load network modules
9. get IP address via DHCP
10. get synchronization and parameter file via TFTP, wait for synchroniza-
tion
11. get (one or more) operation system images via MTFTP1and store into
RAM disk
12. (optional) compare MD5 checksum to parameter file entries
13. get local configuration files (/etc/resolv.conf, /etc/ntp.conf, /etc/syslog.conf,
etc.) via MTFTP into file system mounted from RAM disk
14. exit linuxrc, continue booting into mounted RAM disk
15. start init process
16. load hardware kernel modules (RS485 etc).
17. start applications
1Multicast TFTP
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2.3 Cash Register
2.3.5 Graphical Display Configuration
The graphics controller depends on the model type, so it can be derived from
static tables. Displays that can be probed for their capabilities can be attached
to POS terminals with different model types.
Each POS terminal and each model type has an LDAP entry that can specify
the XF86Config file to download at boot time. A default is provided for the
model types and can be modified by the customer.
Specific POS terminal models can use multihead X configurations. The corre-
sponding XF86Config files are POS hardware manufacturer-specific and will
not be provided by the SLRS.
If no XF86Config file is specified in LDAP, but the system image contains an X
server, an attempt to probe the display type is made. Probing must be defined
by the POS hardware manufacturer.
2.3.6 Hard Disk Installation
A system that has a hard disk can be set up to use it to store the image on a
disk partition instead of a RAM disk and also to boot from the hard disk if it
cannot boot over the network.
2.3.7 CD Boot Installation
For system installation without a network, the system can also be installed
from an IDE CD-ROM drive.
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2 Architectural Overview
20