SUSE Linux Enterprise Desktop Administration Chapter 14 Customize

SUSE Linux Enterprise Desktop Administration Chapter 14 Customize the Graphical Interface on SUSE Linux Enterprise Desktop 10

Objectives • Objective 1—Configure X, Xgl, and Compiz • Objective 2—Customize the GNOME User Interface • Objective 3—Define Mandatory Settings with GConf and Desktop Profile Editor • Objective 4—Customize Applications • Objective 5—Control Mounting of CD-ROM, DVD, and USB Devices SUSE Linux Enterprise Desktop Administration 2

Objective 1—Configure X, Xgl, and Compiz • SUSE Linux Enterprise Desktop 10 provides an entirely new Linux desktop experience – Through its use of 3 D effects made possible by Xgl and Compiz – See Figure 14 -1 • Xgl is a new X Server architecture layered on top of Open. GL – Can perform intricate graphical operations noticeably faster than other available X Servers that do not use Open. GL SUSE Linux Enterprise Desktop Administration 3

Figure 14 -1 New SLED 10 Linux desktop SUSE Linux Enterprise Desktop Administration 4

Objective 1—Configure X, Xgl, and Compiz (continued) • Compiz is a combination of a window manager and a composite manager using Open. GL for rendering • Window manager – Allows the manipulation of the multiple applications and dialog windows that are presented on the screen • Composite manager – Allows windows and other graphics to be combined to create composite images, such as those used to create transparency effects SUSE Linux Enterprise Desktop Administration 5

Configure X • Ya. ST Graphics Card and Monitor Module – Uses sax 2 for the X configuration – Activate 3 D acceleration by checking the Activate 3 D Acceleration option – See Figure 14 -2 • sax 2 – Possible to use sax 2 directly, without Ya. ST – sax 2 is best started from a text terminal in runlevel 3 • Avoids any possible interference with the currently running X session – See Figures 14 -3 and 14 -4 SUSE Linux Enterprise Desktop Administration 6

Figure 14 -2 Activate 3 D acceleration SUSE Linux Enterprise Desktop Administration 7

Configure X (continued) Figure 14 -3 Activate Sa. X 2 SUSE Linux Enterprise Desktop Administration 8

Figure 14 -4 The Ya. ST Graphics Card and Monitor module SUSE Linux Enterprise Desktop Administration 9

Activate Compiz • Packages needed to activate Compiz: – – – compiz Xgl-hardware-list gnome-session libwnck • Once 3 D acceleration has been activated, log in as a normal user to GNOME and activate Compiz – Select the Computer icon in the lower-left corner of the desktop, open the GNOME Control Center, and start the Desktop Effects control panel SUSE Linux Enterprise Desktop Administration 10

Activate Compiz (continued) Table 14 -1 Frequently used controls SUSE Linux Enterprise Desktop Administration 11

Exercise 14 -1: Activate Compiz (Optional, Depending on Hardware Support) • In this exercise, you configure Compiz, provided the hardware supports it SUSE Linux Enterprise Desktop Administration 12

Objective 2—Customize the GNOME User Interface • You can customize the GNOME user interface in various ways • The system used for storing application preferences in GNOME is Gconf – GConf provides a preferences database, similar to a simple file system • Keys are organized into a directory hierarchy – Each key is either: • A directory containing more keys • A value that is contained in the %gconf. xml file in a key directory SUSE Linux Enterprise Desktop Administration 13

User-Defined Settings • When a user defines the settings for his or her workstation – The settings are written to a %gconf. xml file in a directory beneath ~/. gconf • You can define settings using the gconf-editor – Open a terminal window, type gconf-editor, and press Enter – See Figure 14 -5 • You can also use the gconftool-2 command-line tool to change the GConf setting SUSE Linux Enterprise Desktop Administration 14

Figure 14 -5 The gconf-editor SUSE Linux Enterprise Desktop Administration 15

Default Values • Default values are used for any preferences that are not set specifically by the user • Default values are set in /etc/opt/gnome/gconf. xml. defaults/ • Change default values – You can change the systemwide default values using either gconf-editor or gconftool-2 – You must be logged in as root SUSE Linux Enterprise Desktop Administration 16

Exercise 14 -2: Customize the GNOME User Interface • In this exercise, you set the preference for the mouse click to single click to launch programs that have an icon on the desktop and change the default for the background image SUSE Linux Enterprise Desktop Administration 17

Objective 3—Define Mandatory Settings with GConf and Desktop Profile Editor • You can set mandatory preferences using the following approaches: – Use GConf to set mandatory preference values – Use the desktop profile editor – Lock down the desktop SUSE Linux Enterprise Desktop Administration 18

Use GConf to Set Mandatory Preference Values • gconf-editor – To set or change mandatory settings, you must be logged in as root when you use gconf-editor – Set preferences as mandatory for the first time • Start gconf-editor • Browse the tree to the key you want to set as mandatory and set it to the desired value • Then select the entry with the right mouse button; in the context menu, select Set as Mandatory SUSE Linux Enterprise Desktop Administration 19

Use GConf to Set Mandatory Preference Values (continued) • gconf-editor (continued) – Change existing mandatory preferences • Start gconf-editor • Then select File > New Mandatory Settings • To remove a key from the mandatory preferences, right -click on the entry and select Unset Key • gconftool-2 – When you use gconftool-2, the gconf-editor can be helpful to browse the configuration repository tree to find the correct key and its path SUSE Linux Enterprise Desktop Administration 20

Use the Desktop Profile Editor • The Desktop Profile Editor (Sabayon package) – Allows you as the administrator to set preferences on a per-user basis • Define a profile – Select Computer > More Applications > System > Desktop Profile Editor – You are prompted for the root password – Select Add to add a profile and enter a name – Select the name; then select Edit – See Figure 14 -6 SUSE Linux Enterprise Desktop Administration 21

Use the Desktop Profile Editor (continued) • Define a profile (continued) – When you are done, in the Editing Profile profilename window, select Edit > Changes – See Figure 14 -7 – To make a change mandatory, click on the lock on the respective line – To save your profile, select Profile > Save • The profile is saved in /etc/opt/gnome/desktop-profiles/ profilename. zip SUSE Linux Enterprise Desktop Administration 22

Use the Desktop Profile Editor (continued) Figure 14 -6 Add a new user profile SUSE Linux Enterprise Desktop Administration 23

Figure 14 -7 Editing profiles properties SUSE Linux Enterprise Desktop Administration 24

Use the Desktop Profile Editor (continued) • Assign profiles to users – Select the profile and then Users in the User Profile Editor – See Figure 14 -8 – This information is stored in /etc/opt/gnome/desktopprofiles/users. xml – This, in turn, executes /opt/gnome/sbin/sabayon-apply • For users with a profile, this command copies the files contained in the. zip file to the user’s home directory – A user can at least temporarily circumvent the settings marked as mandatory in the Profile Editor of Sabayon SUSE Linux Enterprise Desktop Administration 25

Use the Desktop Profile Editor (continued) Figure 14 -8 Assign profiles to users SUSE Linux Enterprise Desktop Administration 26

Exercise 14 -3: Set Mandatory Values for Preferences • In this exercise, you use the Desktop Profile Editor to set mandatory preferences • Use the Desktop Profile Editor (Sabayon) to lock the screen of all users after five minutes of inactivity SUSE Linux Enterprise Desktop Administration 27

Lock Down the Desktop • Use GConf – The gconf-editor interface lists keys to lock down the desktop in the tree on the left under Desktop > GNOME > Lockdown – To prevent users from changing these settings, you should configure them in the mandatory part of the GConf repository • Use the Desktop Profile Editor (Sabayon) – Offers some more options to restrict users SUSE Linux Enterprise Desktop Administration 28

Lock Down the Desktop (continued) • Use the Desktop Profile Editor (Sabayon) – Start the Desktop Profile Editor; then select Edit > Lockdown in the xnest window menu – See Figure 14 -9 – Select the items that you want to disable – To make the settings mandatory, select Edit > Changes in the menu of the xnest window and select the lock icon in front of the respective entries – See Figure 14 -10 – Save by selecting File > Save and choose the user or users these settings should be applied to SUSE Linux Enterprise Desktop Administration 29

Figure 14 -9 Using the Desktop Profile Editor SUSE Linux Enterprise Desktop Administration 30

Lock Down the Desktop (continued) Figure 14 -10 Setting properties as mandatory SUSE Linux Enterprise Desktop Administration 31

Exercise 14 -4: Disable Access to the Command Line • In this exercise, you use gconf-editor to disable access to the command line on the GNOME desktop • Use gconf-editor to make the command line unavailable on the desktop SUSE Linux Enterprise Desktop Administration 32

Objective 4—Customize Applications • This objective covers two examples of configuration settings that can be made available to all users: – Open. Office. org 2. 0 – Firefox SUSE Linux Enterprise Desktop Administration 33

Open. Office. org 2. 0 • Language Settings – Many different languages are available, but they are contained in separate packages – To install a language, open a terminal window and enter, as root, yast 2 sw_single • Search for Office and select the package for the desired language – Then start Open. Office. org and select Tools > Options > Language Settings > Language – Within a user’s home directory, the configuration directory for Open. Office. org on SLED 10 is ~/. ooo-2. 0 SUSE Linux Enterprise Desktop Administration 34

Open. Office. org 2. 0 (continued) • Templates – Companies usually develop their own templates for company-specific documents – Open. Office. org looks for templates in: • Subdirectories of the systemwide /usr/lib/ooo 2. 0/share/template/language/ directory • The user’s home directory in /. ooo-2. 0/user/template/ – If a user selects File > New > Templates and Documents > Templates, the user will find the company templates in a directory SUSE Linux Enterprise Desktop Administration 35

Open. Office. org 2. 0 (continued) Figure 14 -11 Open. Office Templates and Documents SUSE Linux Enterprise Desktop Administration 36

Firefox • Firefox can be configured extensively via Edit > Preferences • Several tabs cover various aspects of the configuration – See Figure 14 -12 • You can also access the preferences at about: config – See Figure 14 -13 • Changed values are stored in the home directory of the user in /. mozilla/firefox/ xxxx. default/prefs. js SUSE Linux Enterprise Desktop Administration 37

Figure 14 -12 Firefox preferences SUSE Linux Enterprise Desktop Administration 38

Figure 14 -13 Firefox about: config SUSE Linux Enterprise Desktop Administration 39

Objective 5—Control Mounting of CDROM, DVD, and USB Devices • To control the automatic mounting of media, you have to understand how to do the following: – Use the GNOME Volume Manager – Disable Automatic Mounting of Media SUSE Linux Enterprise Desktop Administration 40

Use the GNOME Volume Manager • The GNOME Volume Manager (gnome-volumemanager) – Started automatically when the GNOME desktop is launched – Monitors volume-related events and responds with a user-specified policy • The GConf editor lists the available keys under Desktop >GNOME > Volume Manager – See Figure 14 -14 SUSE Linux Enterprise Desktop Administration 41

Figure 14 -14 GNOME Volume Manager SUSE Linux Enterprise Desktop Administration 42

Disable Automatic Mounting of Media • Various methods of configuration – GConf and /etc/fstab • Use gconftool-2 to set the automount_drives and automount_media keys in /desktop/gnome/volume_manager in the mandatory GConf repository to false – Kernel modules • To read from USB storage devices, the usb_storage kernel module is needed • Prevent the module from being loaded by entering the following line in /etc/modprobe. conf. local SUSE Linux Enterprise Desktop Administration 43

Disable Automatic Mounting of Media (continued) • Various methods of configuration (continued) – Configure udev rules • With udev, device files are created only for actually present devices • udev is very flexible and can be configured by writing rules to *. rules files in the /etc/udev/rules. d/ directory • A rule to disable devices that require the usb_storage module could look like the following: SUSE Linux Enterprise Desktop Administration 44

Disable Automatic Mounting of Media (continued) • Various methods of configuration (continued) – Remove the hardware • Physically remove CD-ROM and DVD drives as well as USB ports • Also prevents the computer from being booted from bootable CDs SUSE Linux Enterprise Desktop Administration 45

Summary • Xgl and the Compiz window manager work with the X Window System and your KDE or GNOME desktop environment • To configure your video graphics card and monitor for use with X, you can use Ya. ST or sax 2 • You can use GConf to customize the GNOME user interface for the system for individual users as well as lock down access to certain desktop areas • To configure GConf, you can use gconf-editor, gconftool-2, or the GNOME Preferences panel SUSE Linux Enterprise Desktop Administration 46

Summary (continued) • The Desktop Profile Editor can be used in addition to GConf to create custom desktop settings profiles for different user accounts – Or lock down access to the desktop • You can customize graphical applications using Ya. ST, as well as configure program preferences, alter configuration files, and create templates • To enhance security on a computer that has removable media devices, you should prevent regular users from mounting removable media SUSE Linux Enterprise Desktop Administration 47