Using the desktop environment in RHEL 8

Procedure

1. Open GNOME Software.

   

2. Go to Graphics & Photography.

3. Browse the available tools, such as the following:

   Photos

   For accessing, organizing and sharing your photos.

   GNU Image Manipulation Program

   For creating images and editing photographs.

   Inkspace

   For creating and editing scalable vector graphics images.

   XSane

   For scanning images with a scanner.

   LibreOffice Draw

   For create and editing drawings, flow charts, and logos.

Procedure

1. Open Tweaks.

   The Tweaks tool

   

2. Select the item that you want to customize in the left side bar.

   For example, you can set applications to start automatically when you log in by using the Startup Applications menu, or you can customize your top bar appearance by using the Top Bar menu.

   Customizing startup applications in Tweaks

   

   Customizing the appearance of your top bar in Tweaks

   

Procedure

1. Open the /usr/share/gnome-shell/modes/classic.json file as the root user.

2. Find the following line in the file:

   "hasOverview": false

3. Change the line to the following:

   "hasOverview": true

4. Save changes, and close the /usr/share/gnome-shell/modes/classic.json file.
5. Restart the user session.

Verification

1. In your GNOME Classic session, open multiple windows.
2. Press the Super key to open the window overview.

3. In the overview, check that:

   • The Dash (the vertical panel on the left side of the screen) is displayed.
   • The bottom panel is not displayed.

   • The workspace switcher is displayed on the right side of the screen.

     Window overview with "hasOverview": true

     

   With the default settings ("hasOverview": false), the overview has the following features:

   • The Dash is not displayed.

   • The bottom panel is displayed. It includes the Window picker button in its left part and the workspace switcher in its right part.

     Window overview with "hasOverview": false

     

Procedure

1. From the login screen (GDM), click the gear button next to the Sign In button.

   Note

   You cannot access this option from the lock screen. The login screen appears when you first start Red Hat Enterprise Linux 8 or when you log out of your current session.

   

2. From the drop-down menu that appears, select the option that you prefer.

   Note

   Note that in the menu that appears on the login screen, the X.Org display server is marked as X11 display server.

Procedure

1. Launch the GNOME Software application.

2. Find the application to be installed in the available categories:

   • Audio & Video
   • Communication & News
   • Productivity
   • Graphics & Photography

   • Add-ons

     Add-ons include for example GNOME Shell extensions, codecs, or fonts.

   • Developer Tools
   • Utilities

   

3. Click the selected application.

   

4. Click the Install button.

   

Procedure

1. Try opening a file that is associated with an application that is currently not installed on your system.
2. GNOME automatically identifies the suitable application that can open the file, and offers to download the application.

Procedure

1. Download the required RPM package.

2. In the Files application, open the directory that stores the downloaded RPM package.

   Note

   By default, downloaded files are stored in the /home/user/Downloads/ directory.

3. Double-click the icon of the RPM package to install it.

Procedure

1. Open the Activities Overview screen.

2. Start typing the name of the required application in the search entry.

   

   GNOME automatically finds the application in a repository, and displays the application’s icon.

3. Click the application’s icon to open GNOME Software.

   

4. Click the icon of the application again.

   

5. Click Install to finish the installation in GNOME Software.

Procedure

1. Open the system menu, which is accessible from the upper-right screen corner, and click the Settings icon.

   

2. In the Details → About section, click Register.
3. Select Registration Server.
4. If you are not using the Red Hat server, enter the server address in the URL field.
5. In the Registration Type menu, select Red Hat Account.

6. Under Registration Details:

   • Enter your Red Hat account user name in the Login field.
   • Enter your Red Hat account password in the Password field.
   • Enter the name of your organization in the Organization field.
7. Click Register.

Procedure

1. Open the system menu, which is accessible from the upper-right screen corner, and click the Settings icon.

   

2. In the Details → About section, click Register.
3. Select Registration Server.
4. If you are not using the Red Hat server, enter the server address in the URL field.
5. In the Registration Type menu, select Activation Keys.

6. Under Registration Details:

   • Enter your activation keys in the Activation Keys field.

     Separate your keys by a comma (,).

   • Enter the name or ID of your organization in the Organization field.
7. Click Register.

Procedure

1. Open the system menu, which is accessible from the upper-right screen corner, and click the Settings icon.

   

2. In the Details → About section, click Details.

   The Registration Details screen appears.

3. Click Unregister.

   A warning appears about the impact of unregistering the system.

4. Click Unregister.

Procedure

1. Identify the GSettings schemas, keys, and allowed values of the settings that you want to configure.

   You cna either use the dconf editor application or the gsettings utility. For details on gsettings, see Working with GSettings keys on command line.

2. Ensure that the /etc/dconf/profile/user configuration file enables the user profile:

   user-db:user
   system-db:local

3. Create a plain text keyfile for the default settings in the /etc/dconf/db/local.d/ directory.

   Choose a file name that represents the settings. The file name usually starts with a number, such as /etc/dconf/db/local.d/01-background.

4. In the keyfile, specify the default settings in the following format:

   [path/to/schema]
   key-name=value
   another-key-name=another-value

   Important

   Separate the schema components with a slash (/), not a dot (.) here.

   Example 6.2. A default background

   For example, to set a default desktop background, specify the following configuration in /etc/dconf/db/local.d/01-background:

   [org/gnome/desktop/background]
   picture-uri='file:///usr/local/share/backgrounds/wallpaper.jpg' 1
   picture-options='scaled' 2
   primary-color='000000' 3
   secondary-color='FFFFFF' 4

   1

   URI to use for the background image. Note that the backend only supports local file:// URIs.

   2

   Determines how the image set by wallpaper_filename is rendered.

   3

   Left or Top color when drawing gradients, or the solid color.

   4

   Right or Bottom color when drawing gradients, not used for solid color.

5. Update the system databases:

   # dconf update

6. The user must log out and log in again for the changes to take effect.

Procedure

1. Create the /etc/dconf/db/local.d/locks/ directory.
2. In this directory, add any number of files listing keys that you want to lock.

Procedure

1. Create the /etc/dconf/profile/user file and add the following to it:

   service-db:keyfile/user

   With this setting, dconf polls the keyfile back end to determine whether updates have been made, so settings might not be updated immediately.

2. The changes take effect when the users logs out and in.

Procedure

1. Create the /usr/share/mime/packages/application-x-newtype.xml file with following content:

   <?xml version="1.0" encoding="UTF-8"?>
   
   <mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
     <mime-type type="application/x-newtype">
       <comment>new mime type</comment>
       <glob pattern="*.xyz"/>
     </mime-type>
   </mime-info>

   The sample application-x-newtype.xml file here defines a new MIME type application/x-newtype and assigns file names with the .xyz extension to that MIME type.

2. Create a new .desktop file named, for example, myapplication1.desktop in the /usr/share/applications/ with following content:

   [Desktop Entry]
   Type=Application
   MimeType=application/x-newtype
   Name=My Application 1
   Exec=myapplication1 field_code

   The sample myapplication1.desktop file here associates the application/x-newtype MIME type with an application named My Application 1. It is run by a command myapplication1.

   Based on how myapplication1 gets started, choose one respective field code from Desktop Entry Specification. For example, for an application capable of opening multiple files, use:

   Exec=myapplication1 %F

3. As a root user, update the MIME database for your changes to take effect.

   # update-mime-database /usr/share/mime

4. As a root user, update the application database.

   # update-desktop-database /usr/share/applications

Verification

1. To verify that you have successfully associated *.xyz files with the application/x-newtype MIME type, first create an empty file, for example test.xyz and execute the following commands:

   $ touch test.xyz
   
   $ gvfs-info test.xyz | grep "standard::content-type"
     standard::content-type: application/x-newtype

2. To verify myapplication1.desktop is correctly set as the default registered application for the application/x-newtype MIME type, execute following command:

   $ gio mime --query application/x-newtype
   Default application for 'application/x-newtype': myapplication1.desktop
   Registered applications:
   	myapplication1.desktop
   Recommended applications:
   	myapplication1.desktop

Procedure

1. Create the ~/.local/share/mime/packages/application-x-newtype.xml file with following content:

   <?xml version="1.0" encoding="UTF-8"?>
   <mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
     <mime-type type="application/x-newtype">
       <comment>new mime type</comment>
       <glob pattern="*.xyz"/>
     </mime-type>
   </mime-info>

   The sample application-x-newtype.xml file here defines a new MIME type application/x-newtype and assigns file names with the .xyz extension to that MIME type.

2. Create a new .desktop file named, for example, myapplication1.desktop, and place it in the ~/.local/share/applications/ directory with following content:

   [Desktop Entry]
   Type=Application
   MimeType=application/x-newtype
   Name=My Application 1
   Exec=myapplication1 field_code

   The sample myapplication1.desktop file above associates the application/x-newtype MIME type with an application named My Application 1. It is run by a command myapplication1.

   Based on how myapplication1 gets started, choose one respective field code from Desktop Entry Specification. For example, for an application capable of opening multiple files, use:

   Exec=myapplication1 %F

3. Update the MIME database for your changes to take effect:

   $ update-mime-database ~/.local/share/mime

4. Update the application database:

   $ update-desktop-database ~/.local/share/applications

Verification

1. To verify that you have successfully associated *.xyz files with the application/x-newtype MIME type, first create an empty file, for example, test.xyz and execute the following commands:

   $ touch test.xyz
   
   $ gvfs-info test.xyz | grep "standard::content-type"
     standard::content-type: application/x-newtype

2. To verify that myapplication1.desktop is correctly set as the default registered application for the application/x-newtype MIME type, execute following command:

   $ gio mime --query application/x-newtype
   Default application for 'application/x-newtype': myapplication1.desktop
   Registered applications:
   	myapplication1.desktop
   Recommended applications:
   	myapplication1.desktop

1. /usr/share/applications/
2. /etc/xdg/
3. ~/.local/share/application/

1. mimeapps.list
2. gnome-mimeapps.list

Procedure

1. Consult the /usr/share/applications/mimeapps.list file to determine the MIME types for which you want to change the default registered application. For example, the following sample of the mimeapps.list file specifies the default registered application for the text/html and application/xhtml+xml MIME types:

   [Default Applications]
   text/html=firefox.desktop
   application/xhtml+xml=firefox.desktop

   This example above specifies default application (Mozilla Firefox) by specifying its corresponding .desktop file (firefox.desktop). You can find .desktop files for other applications in the /usr/share/applications/ directory.

2. Create the /etc/xdg/mimeapps.list file and specify the MIME types and their corresponding default registered applications in this file.

   [Default Applications]
   text/html=myapplication1.desktop
   application/xhtml+xml=myapplication2.desktop

   This example above sets the default registered application for the text/html MIME type to myapplication1.desktop and application/xhtml+xml MIME type to myapplication2.desktop.

Procedure

1. Consult the /usr/share/applications/mimeapps.list file to determine the MIME types for which you want to change the default registered application. For example, the following sample of the mimeapps.list file specifies the default registered application for the text/html and application/xhtml+xml MIME types:

   [Default Applications]
   text/html=firefox.desktop
   application/xhtml+xml=firefox.desktop

   This example above specifies default application (Mozilla Firefox) by specifying its corresponding .desktop file (firefox.desktop). You can find .desktop files for other applications in the /usr/share/applications/ directory.

2. Create the ~/.local/share/applications/mimeapps.list file and specify the MIME types and their corresponding default registered applications in this file.

   [Default Applications]
   text/html=myapplication1.desktop
   application/xhtml+xml=myapplication2.desktop

   This example above sets the default registered application for the text/html MIME type to myapplication1.desktop and application/xhtml+xml MIME type to myapplication2.desktop.

Procedure

1. Create the /etc/dconf/db/gdm.d/01-override-logo configuration file with the following content:

   [org/gnome/login-screen]
   logo='/path/to/logo.png'

   Replace /path/to/logo.png with the full path to the image file that you want to use as the login screen logo.

2. Update the system databases:

   # dconf update

Verification

1. Log out or otherwise switch to the login screen.
2. Check if it displays the logo that you selected.

3. If the logo does not update, restart GDM:

   # systemctl restart gdm

   Warning

   Restarting the gdm service terminates all currently running GNOME sessions of all desktop users who are logged in. This might result in users losing unsaved data.

Procedure

1. Open the Settings application from the system menu by clicking on its icon.

   

2. In Settings, choose Region & Language from the left vertical bar.

3. Click the Language menu.

   

4. Select the required region and language from the menu.

   

   If your region and language are not listed, scroll down, and click More to select from available regions and languages.

   

5. Click Done.

6. Click Restart for changes to take effect.

   

Procedure

1. Create a local database for machine-wide settings in /etc/dconf/db/local.d/00-input-sources:

   [org/gnome/desktop/input-sources]
   # Enable Ctrl-Alt-Backspace for all users
   xkb-options=['terminate:ctrl_alt_bksp']

2. Override the user’s setting, and prevent the user from changing it in /etc/dconf/db/local.d/locks/input-sources:

   # Lock the list of enabled XKB options
   /org/gnome/desktop/input-sources/xkb-options

3. Update the system databases for the changes to take effect:

   # dconf update

4. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Open the /etc/systemd/logind.conf file for editing.

2. Find the HandleLidSwitch=suspend line in the file.

   If it is quoted out with the # character at the start, unquote it by removing #.

   If the line is not present in the file, add it.

3. Replace the default suspend parameter with:

   • lock for the screen to lock
   • ignore for nothing to happen
   • poweroff for the computer to switch off

   For example:

   [Login]
   HandleLidSwitch=lock

4. Save your changes, and close the editor.

5. Run the following command so that your changes preserve the next restart of the system:

   # systemctl restart systemd-logind.service

   Warning

   Restarting the service forcibly interrupts any currently running GNOME session of any desktop user who is logged in. This can result in users losing unsaved data.

Procedure

1. Install the gnome-shell-extension-classification-banner package:

   # yum install gnome-shell-extension-classification-banner

   Note

   The package is only available in RHEL 8.6 and later.

2. Create the 99-class-banner file at either of the following locations:

   • To configure a notification at the login screen, create /etc/dconf/db/gdm.d/99-class-banner.
   • To configure a notification in the user session, create /etc/dconf/db/local.d/99-class-banner.

3. Enter the following configuration in the created file:

   [org/gnome/shell]
   enabled-extensions=['classification-banner@gnome-shell-extensions.gcampax.github.com']
   
   [org/gnome/shell/extensions/classification-banner]
   background-color='rgba(200,16,46,0.75)'
   message='TOP SECRET'
   top-banner=true
   bottom-banner=true
   system-info=true
   color='rgb(255,255,255)'

   Warning

   This configuration overrides similar configuration files that also enable an extension, such as Notifying of the system security classification.

   To enable multiple extensions, specify all of them in the enabled-extensions list. For example:

   enabled-extensions=['heads-up-display@gnome-shell-extensions.gcampax.github.com', 'classification-banner@gnome-shell-extensions.gcampax.github.com']

4. Update the dconf database:

   # dconf update

5. Reboot the system.

Procedure

1. Install the gnome-shell-extension-heads-up-display package:

   # yum install gnome-shell-extension-heads-up-display

2. Create the 99-hud-message file at either of the following locations:

   • To configure a notification at the login screen, create /etc/dconf/db/gdm.d/99-hud-message.
   • To configure a notification in the user session, create /etc/dconf/db/local.d/99-hud-message.

3. Enter the following configuration in the created file:

   [org/gnome/shell]
   enabled-extensions=['heads-up-display@gnome-shell-extensions.gcampax.github.com']
   
   [org/gnome/shell/extensions/heads-up-display]
   message-heading="Security classification title"
   message-body="Security classification description"
   # The following options control when the notification appears:
   show-when-locked=true
   show-when-unlocking=true
   show-when-unlocked=true

   Replace the following values with text that describes the security classification of your system:

   Security classification title

   A short heading that identifies the security classification.

   Security classification description

   A longer message that provides additional details, such as references to various guidelines.

   Warning

   This configuration overrides similar configuration files that also enable an extension, such as Enabling system security classification banners.

   To enable multiple extensions, specify all of them in the enabled-extensions list. For example:

   enabled-extensions=['heads-up-display@gnome-shell-extensions.gcampax.github.com', 'classification-banner@gnome-shell-extensions.gcampax.github.com']

4. Update the dconf database:

   # dconf update

5. Reboot the system.

Procedure

1. Go to the system menu, which is accessible from the top-right screen corner, and click Settings.

   

2. Select the Region & Language section.

3. In the Input Sources list, review the currently enabled input methods.

   

4. If your input method is missing:

   1. Click the + button under the Input Sources list.

      

   2. Select your language.

      
      Note

      If you cannot find your language in the menu, click the three dots icon (More…) at the end of the menu.

   3. Select the input method that you want to use. A cog wheel icon marks all input methods to distinguish them from simple keyboard layouts.

      
   4. Confirm your selection by clicking Add.

5. Switch the active input method using one of the following ways:

   • Click the input method indicator on the right side of the top panel and select your input method.

     
   • Switch between the enabled input methods using the Super+Space keyboard shortcut.

Verification

1. Open a text editor.
2. Type text in your language.
3. Verify that the text appears in your native script.

Procedure

1. Open the Tweaks application.
2. Select Keyboard & Mouse in the side bar.
3. Enable Compose Key.

4. Choose which key from the listed keys triggers the Compose functionality.

   

Procedure

1. Allow all clients to connect to the X server:

   # xhost +

2. Run the following command to set the Compose Key:

   # su - <username> -c "gsettings set org.gnome.desktop.input-sources xkb-options \"['compose:<compose_key>']\""

   Replace <username> with the username of the user for whom you want to enable the Compose Key. Replace <compose_key> with the key you want to use as the Compose Key. You can use the ralt option to designate the right Alt key as the Compose Key.

   To see other Compose Key options that you can use to set up a Compose Key on your keyboard, use:

   $ grep compose /usr/share/X11/xkb/rules/evdev.lst

3. Resets the access control:

   # xhost -

Procedure

1. Open the /etc/dconf/db/local.d/00-input-sources file as the root user.

2. Enter the following content in the file:

   [org/gnome/desktop/input-sources]
   # Enable the Compose key
   xkb-options=['compose:selected-key']

   Replace selected-key with the key that triggers Compose. For example, use ralt to set the right Alt key.

3. To override the user’s Compose settings and prevent the user from changing them, create the /etc/dconf/db/local.d/locks/input-sources file and enter the following:

   # Lock the list of enabled XKB options
   /org/gnome/desktop/input-sources/xkb-options

4. Update the system databases for the changes to take effect:

   # dconf update

5. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Open a GTK application.
2. Make sure that a text field is active.

3. Press Ctrl+..

   The emoji selection menu opens.

4. Browse the emoji characters or type a keyword that identifies the emoji character that you want to insert, such as smile.

   For the full list of keywords associated with emoji characters, see the Other Keywords column on the Emoji List page.

5. Click the selected character, or navigate to it using the cursor keys and press Enter.

Procedure

1. Open an application.
2. Make sure that a text field is active.

3. Press Ctrl+Shift+e.

   The underscored letter e appears at your cursor.

4. Type a keyword that identifies the emoji character that you want to insert, such as smile.

   For the full list of keywords associated with emoji characters, see the Other Keywords column on the Emoji List page.

5. Repeatedly press Space to browse the emoji characters that match your keyword.
6. Confirm the selected emoji character by pressing Enter.

Procedure

1. Open the Files application.

2. Click Other Locations in the side bar.

   The window lists all connected storage volumes and all network shares that are publicly available on your local area network.

   If you can see the volume or network share in this list, mount it by clicking the item.

   If you want to connect to a different network share, use the following steps.

3. Enter the GVFS URI string to the network share in the Connect to Server field.
4. Press Connect.
5. If the dialog asks you for login credentials, enter your name and password into the relevant fields.
6. When the mounting process finishes, you can browse the files on the volume or network share.

Procedure

1. Open the Files application.
2. In the side bar, click the Unmount (⏏) icon next to the chosen mount.
3. Wait until the mount disappears from the side bar or a notification about the safe removal appears.

Procedure

1. Create an empty file:

   $ touch /tmp/myfile

2. View the metadata of this file:

   $ gio info -a 'metadata::*' /tmp/myfile
   uri: file:///tmp/myfile
   attributes:

3. Set a string to this file:

   $ gio set -t string /tmp/myfile 'metadata::mynote' 'Please remember to delete this file!'

4. View the metadata:

   $ gio info -a 'metadata::*' /tmp/myfile
   uri: file:///tmp/myfile
   attributes:
     metadata::mynote: Please remember to delete this file!

5. Move this file to a new location:

   $ gio move /tmp/myfile /tmp/newfile

6. View the metadata:

   $ gio info -a 'metadata::*' /tmp/newfile
   uri: file:///tmp/newfile
   attributes:
     metadata::mynote: Please remember to delete this file!

Procedure

1. Ensure that gvfs-fuse is running.

   $ ps ax | grep gvfsd-fuse

   If gvfs-fuse is not running, log out and log back in. Red Hat does not recommend starting gvfs-fuse manually.

2. Find the system user ID (UID) for the /run/user/UID/gvfs/ path.

   The gvfsd-fuse daemon requires a path where it can expose its services. When the /run/user/UID/gvfs/ path is unavailable, gvfsd-fuse uses the ~/.gvfs path.

   $ id -u

3. If gvfsd-fuse is still not running, start the gvfsd-fuse daemon:

   $ /usr/libexec/gvfsd-fuse -f /run/user/_UID_/gvfs

   Now, the FUSE mount is available, and you can manually browse for the path in your application.

4. Find the GVFS mounts under the /run/user/UID/gvfs/ or ~/.gvfs locations.

Procedure

1. Open the Disks application.
2. Select the disk in the side bar.
3. Below Volumes, Click Additional partition options (⚙) → Edit Mount Options…​.
4. Click Show in user interface.
5. Confirm by clicking OK.
6. If the flash drive is still not visible, you can try to physically remove the drive and try connecting it again.

Procedure

1. Open the Disks application.
2. Select the disk in the side bar.
3. Below Volumes, Click Additional partition options (⚙) → Edit Mount Options…​.
4. Uncheck Show in user interface.
5. Confirm by clicking OK.

Procedure

1. Unmount file system.
2. Mount it again.
3. If the connection is getting disabled more often, check the settings in the Network panel in the GNOME Settings.

Procedure

1. Examine the list of open files.

   • Run the lsof command to get the list of open files.
   • If lsof is not available, run the ps ax command.
   • You can use System Monitor to display the running processes in a GUI.

2. When you have determined the programs, terminate them using any of the following methods:

   • On the command line, execute the kill command.
   • In System Monitor, right-click the line with the program process name, and click End or Kill from the context menu.

Procedure

1. Select the folder or file you want to bookmark.

2. Do one of the following:

   • Press Ctrl+D or
   • Drag and drop the file or folder to the sidebar.

Procedure

1. In the home directory of each existing user, edit the ~user/.config/gtk-3.0/bookmarks file.

2. In the file, add a Uniform Resource Identifiers (URI) line that identifies the bookmark.

   For example, the following lines add bookmarks to the /usr/share/doc/ directory and to the GNOME FTP network share:

   file:///usr/share/doc/
   ftp://ftp.gnome.org/

3. Optional: To also add the bookmarks for every newly created user on the system:

   1. Create the /etc/skel/.config/gtk-3.0/bookmarks file.
   2. Enter the bookmark URI lines in the file.

Procedure

1. Open the Activities overview by clicking Activities at the top left of the screen.

2. Add applications into your favorite list using any of the following methods:

   • Click the grid button to find the application you want, right-click the application icon, and select Add to Favorites.
   • Click-and-drag the icon into the dash.

3. View all the applications that exists in the favorite list:

   $ dconf read /org/gnome/shell/favorite-apps

Procedure

1. Create the key file /etc/dconf/db/local.d/00-favorite-apps to provide information for the local database. /etc/dconf/db/local.d/00-favorite-apps contents:

   # Snippet sets gedit, terminal and nautilus as default favorites for all users
   [org/gnome/shell]
   favorite-apps = ['gedit.desktop', 'gnome-terminal.desktop', 'nautilus.desktop']

2. To prevent users from overriding these settings, create the file /etc/dconf/db/local.d/locks/favorite-apps with the following content:

   # Lock default favorite applications
   /org/gnome/shell/favorite-apps

3. Run the dconf update command to incorporate your changes into the system databases.
4. Logout and login again for system-wide changes to take effect.

Procedure

1. Create the user profile in /etc/dconf/profile/user unless it already exists:

   user-db:user
   system-db:local

2. Create a local database for machine-wide settings in the etc/dconf/db/local.d/00-lockdown file:

   [org/gnome/desktop/lockdown]
   
   # Prevent applications from printing
   disable-printing=true

3. Override the user’s setting and prevent the user from changing it in the /etc/dconf/db/local.d/locks/lockdown file:

   # List the keys used to configure lockdown
   /org/gnome/desktop/lockdown/disable-printing

4. Update the system databases:

   # dconf update

Procedure

1. Create the user profile in /etc/dconf/profile/user unless it already exists:

   user-db:user
   system-db:local

2. Create a local database for machine-wide settings in the /etc/dconf/db/local.d/00-lockdown file:

   [org/gnome/desktop/lockdown]
   
   # Prevent the user from saving files on disk
   disable-save-to-disk=true

3. Override the user’s setting and prevent the user from changing it in the /etc/dconf/db/local.d/locks/lockdown file:

   # Lock this key to disable saving files on disk
   /org/gnome/desktop/lockdown/disable-save-to-disk

4. Update the system databases:

   # dconf update

Procedure

1. Create a file with the same content as in /usr/share/polkit-1/actions/org.freedesktop.udisks2.policy:

   cp /usr/share/polkit-1/actions/org.freedesktop.udisks2.policy /etc/share/polkit-1/actions/org.freedesktop.udisks2.policy

   Do not change the /usr/share/polkit-1/actions/org.freedesktop.udisks2.policy file, your changes will be overwritten by the next package update.

2. Delete the action you do not need, and add the following lines to the /etc/polkit-1/actions/org.freedesktop.udisks2.policy file:

   <action id="org.freedesktop.udisks2.modify-device">
     <message>Authentication is required to modify the disks settings</message>
        <defaults>
           <allow_any>no</allow_any>
           <allow_inactive>no</allow_inactive>
           <allow_active>yes</allow_active>
         </defaults>
    </action>

   Replace no by auth_admin if you want to ensure only the root user is able to perform the action.

3. Save the changes.

Procedure

1. Create the /etc/dconf/profile/user profile, which contains the following lines:

   user-db:user
   system-db:local

   where local is the name of a dconf database

2. Create the /etc/dconf/db/local.d/ directory if it does not already exist.

3. Create the /etc/dconf/db/local.d/00-logout key file to provide information for the local database:

   [org/gnome/desktop/lockdown]
   # Prevent the user from user switching
   disable-log-out=true

4. Override the user’s setting, and prevent the user from changing it in the /etc/dconf/db/local.d/locks/lockdown file:

   # Lock this key to disable user logout
   /org/gnome/desktop/lockdown/disable-log-out

5. Update the system databases:

   # dconf update

6. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Create the /etc/dconf/profile/user profile, which contains the following lines:

   user-db:user
   system-db:local

   where local is the name of a dconf database

2. Create the /etc/dconf/db/local.d/ directory if it does not already exist.

3. Create the /etc/dconf/db/local.d/00-user-switching key file to provide information for the local database:

   # Prevent the user from user switching
   [org/gnome/desktop/lockdown]
   disable-user-switching=true
   
   [org/gnome/desktop/screensaver]
   user-switch-enabled=false

4. Override the user’s setting, and prevent the user from changing it in the /etc/dconf/db/local.d/locks/lockdown file:

   # Lock this key to disable user switching
   /org/gnome/desktop/lockdown/disable-user-switching
   /org/gnome/desktop/screensaver/user-switch-enabled

5. Update the system databases:

   # dconf update

6. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Install the gnome-session-kiosk-session package:

   # yum install gnome-session-kiosk-session

2. As the user that will open the single-application session, create the /home/user/.local/bin/redhat-kiosk file:

   [user]$ mkdir -p ~/.local/bin
   
   [user]$ touch ~/.local/bin/redhat-kiosk

3. Edit the /home/user/.local/bin/redhat-kiosk file and enter the executable name of the application that you want to launch in single-application mode.

   For example, to launch the Firefox browser in single-application mode, enter the following content:

   #!/bin/sh
   
   while true; do
       firefox --kiosk https://example.org
   done

   The while true loop ensures that the application restarts if it terminates for any reason.

4. Make the file executable:

   [user]$ chmod +x ~/.local/bin/redhat-kiosk

5. If you created the file or its containing directories as a different user than the single-application user, such as root, ensure that the file has the correct permissions:

   # chown -R user:group ~user/.local

6. At the GNOME login screen, select the Kiosk session from the gear button menu and log in as the single-application user.

Procedure

1. Create a .desktop file in the /etc/xdg/autostart/ directory, such as /etc/xdg/autostart/nautilus.desktop. Enter the following content in the file:

   [Desktop Entry]
   Type=Application
   Name=Files
   Exec=/usr/bin/nautilus -n
   OnlyShowIn=GNOME;
   X-GNOME-Autostart-enabled=true

   • Replace Files with the name of the application.
   • Replace /usr/bin/nautilus -n with the command that starts the application. Use the full file path.

2. Optional: Configure the application to start only when a selected GSettings key is enabled. GNOME then runs the application automatically if the key’s value is true. If the key’s value changes in the running session, GNOME starts or stops the application to match the new value.

   Add the following line in the .desktop file:

   AutostartCondition=GSettings org.gnome.desktop.background show-desktop-icons

   • Replace org.gnome.desktop.background show-desktop-icons with the GSettings schema and key that the automatic start depends on.

Procedure

1. Create a local database for machine-wide settings in the /etc/dconf/db/local.d/00-autologout file:

   [org/gnome/settings-daemon/plugins/power]
   # Set the timeout to 900 seconds when on mains power
   sleep-inactive-ac-timeout=900
   # Set action after timeout to be logout when on mains power
   sleep-inactive-ac-type='logout'

2. Override the user’s setting, and prevent the user from changing it in the /etc/dconf/db/local.d/locks/autologout file:

   # Lock automatic logout settings
   /org/gnome/settings-daemon/plugins/power/sleep-inactive-ac-timeout
   /org/gnome/settings-daemon/plugins/power/sleep-inactive-ac-type

3. Update the system databases:

   # dconf update

4. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Copy the configuration file template:

   # cp /usr/share/accountsservice/user-templates/standard \
        /etc/accountsservice/user-templates/standard

2. Edit the new /etc/accountsservice/user-templates/standard file. On the Session=gnome line, replace gnome with the session that you want to set as the default.

3. Optional: To configure an exception to the default session for a certain user, follow these steps:

   1. Copy the template file to /var/lib/AccountsService/users/user-name:

      # cp /usr/share/accountsservice/user-templates/standard \
           /var/lib/AccountsService/users/user-name

   2. In the new file, replace variables such as ${USER} and ${ID} with the user values.
   3. Edit the Session value.

Procedure

1. Create a local database for machine-wide settings in the /etc/dconf/db/local.d/00-power file including these lines:

   [org/gnome/settings-daemon/plugins/power]
   idle-dim=true

2. Update the system databases:

   # dconf update

3. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Create a local database for machine-wide settings in the /etc/dconf/db/local.d/00-power file, as in the following example:

   [org/gnome/settings-daemon/plugins/power]
   idle-brightness=30

   Replace 30 with the integer value you want to use.

2. Update the system databases:

   # dconf update

3. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Create a local database for machine-wide settings in /etc/dconf/db/local.d/00-session, as in the following example:

   [org/gnome/desktop/session]
   idle-delay=uint32 900

   Replace 900 with the integer value you want to use.

   You must include the uint32 along with the integer value as shown.

2. Update the system databases:

   # dconf update

3. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. Create a local database for system-wide settings in the etc/dconf/db/local.d/00-screensaver file:

   [org/gnome/desktop/session]
   # Set the lock time out to 180 seconds before the session is considered idle
   idle-delay=uint32 180
   [org/gnome/desktop/screensaver]
   # Set this to true to lock the screen when the screensaver activates
   lock-enabled=true
   # Set the lock timeout to 180 seconds after the screensaver has been activated
   lock-delay=uint32 180

   You must include the uint32 along with the integer key values as shown.

2. Override the user’s setting, and prevent the user from changing it in the /etc/dconf/db/local.d/locks/screensaver file:

   # Lock desktop screensaver settings
   /org/gnome/desktop/session/idle-delay
   /org/gnome/desktop/screensaver/lock-enabled
   /org/gnome/desktop/screensaver/lock-delay

3. Update the system databases:

   # dconf update

4. Users must log out and back in again before the system-wide settings take effect.

Procedure

1. To start the recording, press the Ctrl+Alt+Shift+R shortcut.

   When the recorder is capturing the screen activity, it displays a red circle in the top-right corner of the screen.

2. To stop the recording, press the Ctrl+Alt+Shift+R shortcut.

   The red circle in the top-right corner of the screen disappears.

3. Navigate to the ~/Videos directory where you can find the recorded video with a file name that starts with Screencast and includes the date and time of the recording.

Procedure

1. Go to the system menu, which is accessible from the top-right screen corner, and click the Settings icon.

   

2. In the Settings → Devices section, choose Displays.
3. Configure the rotation using the Orientation field.
4. Confirm your choice by clicking Apply.
5. If you are satisfied with the new setup preview, click on Keep changes.

Procedure

1. Prepare the preferable setup for a single user as in Configuring the screen rotation for a single user.

2. Copy the transform section of the ~/.config/monitors.xml configuration file, which configures the screen rotation. An example portrait orientation:

   <?xml version="1.0" encoding="UTF-8"?>
   
   <transform>
     <rotation>left</rotation>
     <flipped>no</flipped>
   </transform>

3. Paste the content in the /etc/xdg/monitors.xml file that stores system-wide configuration.
4. Save the changes.

Procedure

1. Open the Settings application.
2. Select Universal Access.

3. Enable the Always Show Universal Access Menu item.

   Enabling the Universal Access menu in Settings

   

Verification

1. Open an application with text content.
2. Check that the screen reader reads the text in the application.

Procedure

1. Install the package that provides tablet definition files:

   # yum install libwacom-data

   The package installs tablet definitions in the /usr/share/libwacom/ directory.

2. Check whether the definition file is available in the /usr/share/libwacom/ directory.

   To use the screen mapping correctly, support for your tablet must be included in the libwacom database and in the udev rules file.

   Important

   A common indicator that a device is not supported by libwacom is that it works normally in a GNOME session, but the device is not correctly mapped to the screen.

3. If the definition file for your device is not available in /usr/share/libwacom/, you have these options:

   • The required definition file may already be available in the linuxwacom/libwacom upstream repository. You can try to find the definition file there. If you find your tablet model in the list, copy the file to the local machine.

   • You can create a new tablet definition file. Use the data/wacom.example file below, and edit particular lines based on the characteristics of your device.

     Example 24.1. Example model file description for a tablet

     [Device]
     
     # The product is the product name announced by the kernel
     Product=Intuos 4 WL 6x9
     
     # Vendor name of this tablet
     Vendor=Wacom
     
     # DeviceMatch includes the bus (usb, serial), the vendor ID and the actual
     # product ID
     DeviceMatch=usb:056a:00bc
     
     # Class of the tablet. Valid classes include Intuos3, Intuos4, Graphire, Bamboo, Cintiq
     Class=Intuos4
     
     # Exact model of the tablet, not including the size.
     Model=Intuos 4 Wireless
     
     # Width in inches, as advertised by the manufacturer
     Width=9
     
     # Height in inches, as advertised by the manufacturer
     Height=6
     
     # Optional features that this tablet supports
     # Some features are dependent on the actual tool used, e.g. not all styli
     # have an eraser and some styli have additional custom axes (e.g. the
     # airbrush pen). These features describe those available on the tablet.
     #
     # Features not set in a file default to false/0
     
     [Features]
     # This tablet supports styli (and erasers, if present on the actual stylus)
     Stylus=true
     
     # This tablet supports touch.
     Touch=false
     
     # This tablet has a touch ring (Intuos4 and Cintiq 24HD)
     Ring=true
     # This tablet has a second touch ring (Cintiq 24HD)
     Ring2=false
     
     # This tablet has a vertical/horizontal scroll strip
     VStrip=false
     HStrip=false
     
     # Number of buttons on the tablet
     Buttons=9
     
     # This tablet is built-in (most serial tablets, Cintiqs)
     BuiltIn=false

Procedure

1. Add and install the definition file with the .tablet suffix:

   # cp the-new-file.tablet /usr/share/libwacom/

   Once installed, the tablet is part of the libwacom database. The tablet is then available through libwacom-list-local-devices.

2. Create a new /etc/udev/rules/99-libwacom-override.rules file with the following content so that your settings are not overwritten:

   ACTION!="add|change", GOTO="libwacom_end"
   KERNEL!="event[0-9]*", GOTO="libwacom_end"
   
   [new tablet match entries go here]
   
   LABEL="libwacom_end"

3. Reboot your system.

Procedure

1. Enable the rhel Flatpak remote:

   $ flatpak remote-add \
             --if-not-exists \
             rhel \
             https://flatpaks.redhat.io/rhel.flatpakrepo

2. Log into the Red Hat Container Catalog:

   $ podman login registry.redhat.io
   
   Username: your-user-name
   Password: your-password

   Provide the credentials to your Red Hat Customer Portal account or your registry service account tokens.

   By default, Podman saves the credentials only until you log out.

3. Optional: Save your credentials permanently. Use one of the following options:

   • Save the credentials for the current user:

     $ cp $XDG_RUNTIME_DIR/containers/auth.json \
          $HOME/.config/flatpak/oci-auth.json

   • Save the credentials system-wide:

     # cp $XDG_RUNTIME_DIR/containers/auth.json \
          /etc/flatpak/oci-auth.json

     For best practices, Red Hat recommends that you log into the Red Hat Container Catalog using registry account tokens when installing credentials system-wide.

Procedure

1. Open the Software application.
2. Make sure that the Explore tab is active.
3. Click the search button in the upper-left corner of the window.
4. In the input box, type the name of the application that you want to install, such as LibreOffice.

5. Select the correct application in the search results.

   If the application is listed several times, select the version where the Source field in the Details section reports flatpaks.redhat.io.

6. Click the Install button.
7. If Software asks you to log in, enter your Customer Portal credentials or your registry service account tokens.
8. Wait for the installation process to complete.
9. Optional: Click the Launch button to launch the application.

Procedure

1. Open the Software application.
2. Select the Updates tab.
3. In the Application Updates section, you can find all available updates to Flatpak applications.

4. Update one or more applications:

   • To apply all available updates, click the Update All button.
   • To update only a specific application, click the Update button next to the application item.

5. Optional: Enable automatic application updates.

   1. Click the menu button in the upper-right corner of the window.
   2. Select Update Preferences.

   3. Enable Automatic Updates.

      Flatpak applications now update automatically.