17.2.  Modules

The tlwebadm interface consists of several modules which address different aspects of ThinLinc configuration:

These modules are described in more detail in the following sections.

17.2.1.  The System Health Module

The System Health module allows you to check the running state of the ThinLinc services VSM Master, VSM Agent and Web Access. There is also a tool to perform a user or group lookup which reports the time for the lookup.

  • VSM Master reports current running state of VSM Master service.

  • VSM Agent reports current running state of VSM Agent service.

  • Web Access reports current running state of Web Access service.

  • Users and Group Lookup allows you to test performance of user and group lookup on the system.

    Fill in values for username and/or group and click the Test user and group lookup button to perform a lookup.

17.2.2.  The Status Module

The Status module allows you to view or manipulate the following aspects of ThinLinc, by selecting the relevant submenu:

  • Licenses allows you to view current and historic license usage, as well as the current number of licenses.

  • Load allows you to check the current server load on the ThinLinc agents.

  • Sessions allows you to terminate, shadow or view details of sessions. This feature is described in more detail in the next section, Section 17.2.2.1, “ The Sessions Menu ”

17.2.2.1.  The Sessions Menu

When you select the sessions menu, a table with all currently active users is displayed. To perform additional tasks, click on the corresponding user name. This will bring up the session details page, which displays all the session parameters for each session the user has running. The information table is described below.

  • Agent Server : The DNS host name of the server that is hosting this session. If you only have one ThinLinc server, this server will host all sessions. If you have several ThinLinc servers in a cluster, new sessions will be created on the server with the lightest load.

  • Display Number : Each session on a certain server has a unique number, the X Window System display number. Display zero is reserved, and never used for ThinLinc sessions.

  • Terminal ID : An identification of the thin terminal. This is the terminal's ethernet hardware address (MAC address).

  • Framebuffer Size : The size (resolution) of the active session.

  • Local Screen Size : The size (resolution) of the terminal's screen.

  • Session process ID : The PID (process identification number) of the tl-session process, which is the parent for all processes belonging to a certain session.

  • Command : The command line that was specified when starting this session. This is usually empty for full desktop sessions.

Below each table, there are two buttons:

  • Terminate Session : By clicking this button, you can terminate a session immediately. Caution: This can lead to data loss, since applications running on the ThinLinc servers may not hold unsaved data.

  • Shadow Session : This button will generate a ThinLinc "launch file" (see Section 7.10, “ Launching the Client from a Web Page ”) that starts the native ThinLinc client, preconfigured to shadow the current user.

    Note

    The user will not be informed that shadowing is in progress, unless tl-shadow-notify is enabled.

17.2.3.  The VSM Module

VSM contains information about subclusters and VSM Master and Agent services. This module also allows managing of subclusters and configuration of Master and Agent.

  • Subclusters allows viewing, adding, modifying or deleting subclusters.

  • VSM Master allows starting or stopping the service, and modifying a subset of the configuration options.

  • VSM Agent allows starting or stopping the service, and modifying a subset of the configuration options.

17.2.3.1.  Subclusters

On this page, the configured subclusters of the ThinLinc Master can be found. Subclusters are groups of agents that can be associated with users or groups. Adding, modifying or deleting existing subclusters is possible. A restart of the vsmserver service is required after changes to subcluster configuration in order for the changes to take effect. The vsmserver service can be restarted from the VSM Master-page described in Section 17.2.3.2, “ VSM Master ”.

The page will present a list of currently configured subclusters. This should be something like the example in Figure 17.1. To edit a subcluster, click on its name in the list.

Figure 17.1.  Subclusters

Subclusters

Figure 17.1 shows a system with a total of two subclusters. The subcluster called default is configured with two agent servers and US_cluster is configured with one agent.

To add a new subcluster to the list, press the Add new subcluster button. This will bring up an empty subcluster edit form. See figure Figure 17.2 for an example.

Figure 17.2.  New subcluster form

New subcluster form

There are four editable fields in this view; Subcluster, Agents, Users and Groups. These are described in Section 14.2.3, “ Parameters in /vsmserver/subclusters/ ”. To save changes, press the Save button. Remember to restart the vsmserver service afterwards.

17.2.3.2.  VSM Master

On this page you can start or stop VSM Master service. There are also a subset of configuration options available for configuration of the service.

  • Service Status gives you the ability to start or stop the VSM Master service.

  • Sessions per user allows you to configure how many session are allowed per user.

    A value of zero means no limit and will give unlimited sessions per user.

  • Allowed Groups allows you to configure which groups should be given access to connect to ThinLinc.

    If no groups are specified, all users will have access to connect to ThinLinc

  • Allowed Shadowers allows you to configure which users should be able to shadow other ThinLinc sessions.

Click the Save button when you want to save your changes to the configuration files.

Note

You need to restart the service to apply your changes.

17.2.3.3.  VSM Agent

On this page you can start or stop the VSM Master service. There are also a subset of configuration options available for configuration of the service.

  • Service Status gives you the ability to start or stop the VSM Agent service.

  • Agent Hostname allows you to configure the hostname that clients are redirected to.

    Note

    This configuration is needed if running ThinLinc in a NAT environment. See Section 3.3.4, “ ThinLinc in a NAT/Split-DNS Environment ” for more information.

  • Extra Arguments to X Server allows you to configure additional arguments to the Xserver (Xvnc) for new sessions that are started.

Click the Save button when you want to save your changes to the configuration files.

Note

You need to restart the service to apply your changes.

17.2.4.  The Profiles Module

On this page you can modify text shown in the profile chooser, and manage profiles. You can create or delete a profile and configure the profile order.

  • Introduction Texts allows you to modify and manage translation of texts used in the profile chooser.

  • Profile List allows you to configure the available profiles and their order.

17.2.4.1.  Introduction Texts

Introduction texts contains translation tables for greetings and introduction texts. There is also a configuration option to enable or disable the use of introduction texts.

  • Greeting Text the text to show at the top of the profile chooser.

  • Show Introduction disable or enable the introduction text which is shown to the user before the profile selection dialog.

  • Introduction Text the text to show before presenting the list of profiles.

To add a new translation, fill in language code and the translated string. Click the Save button to save the new translation and add it to the translation table.

To delete a translation select the row using the checkbox in Delete column of the translation table. Click the Save button to carry out the actual deletion of selected rows.

17.2.4.2.  Profile List

The Profile List module contains functionality to manage your profiles. You can change the default profile, or create new and edit existing profiles. You can also change the order of profiles.

  • Default Profile allows you to specify the default profile to be selected in the profile chooser.

  • Profile List allows you to modify profiles and their order, or create new profiles.

Create a new profile by clicking the Add new profile button. If you want to edit an existing profile, click the profile name in the table of available profiles.

When creating a new or editing an existing profile a form is displayed. This form is shared between both modes and each field details are described below.

  • Identification

    An unique string identifier for the profile which is used when referencing this profile.

  • XDG Session Desktop

    The system desktop session configuration that this profile should be connected to.

  • Default Name

    A name for the profile which is displayed in the profile chooser.

  • Availability

    This will make the profile available to be selected and used. If you uncheck it will not be shown to the user in the profile chooser.

  • Take Description From

    The description is shown in the profile chooser when a profile is selected. This field can be a static text which is defined in the input field Default Description .

    • Test command : This will take and use the output of defined Test Command as description for the profile.

    • Manually defined text below : This will use the text defined in the Default Description field below.

  • Default Description

    A text used as description for the profile. This is text is used if Take Description From above is selected to use the manually defined text.

  • Icon Path

    A filename of the icon to use in the profile chooser.

  • Screenshot Path

    A filename of the screenshot to use in the profile chooser.

  • Command Line

    This command is used to start up a session. In most cases this is something simple like xfce4-session, but in some cases there might also be arguments like gnome-session --session gnome-classic.

  • Test Command

    This command is evaluated and if it returns true, the profile is shown to the user. If the command evaluates as false, the profile will not be shown in the list of available profiles for the user.

    ThinLinc includes the tool "tl-memberof-group" which may be used to test memebership of groups. You can use this tool as test command, such as ${TLPREFIX}/bin/tl-memberof-group my_profile_access_group. This example will give memebers of group my_profile_access_group access to the profile.

    If you only want to give a specific user access to the profile you may specify test ${USER} = user.

When you have filled out the form, or changed any fields, click Save button at the bottom of the form to save your changes into the configuration file.

To delete a profile click the profile name in table of available profiles. Then click the checkbox at the bottom of the form to verify your intention about deletion of the profile. Complete the deletion by clicking the Delete button.

17.2.5.  The Locations Module

Locations contains information about locations where terminals and printers reside. A location can be a room, a floor, a house or some other type of geographical delimitation.

Every terminal should be assigned as a member of a location. In addition to terminals, printers may also be assigned to locations.

17.2.5.1.  Terminals

Terminals contains necessary information about all terminals. The most important information here is every terminal's interface hardware (MAC) address.

Each terminal should be entered as described in this section. Enter the terminals module by clicking on the menu item. You will be presented with a list of currently entered terminals. This could be something like the example in Figure 17.3.

Figure 17.3.  Terminals

Terminals

Figure 17.3 shows a system with a total of two terminals.

To edit a terminal, click on its name in the list.

To add a new terminal to the list you press the Add new terminal button. This will bring up an empty terminal edit form. See Figure 17.4 for an example.

Figure 17.4.  New terminal form

New terminal form

There are three editable fields in this view, Hardware (MAC) address , Terminal name and Location . They are described in Table 17.1 below.

To save changes, press the Save button. When you have pressed the Save button you will see that the Hardware (MAC) address field will change from being an editable field to become a static text label. To assure data integrity between the modules you aren't allowed to change this field after it's added.

When a new terminal is saved or when clicking an existing in the terminals list, there will be three buttons inside the form. The Save button is used to save changes made to the terminal. The Delete button deletes the currently viewed terminal. The Add Printer button will add a new printer field to the form.

Table 17.1.  Terminal properties

NameDescription
Hardware (MAC) addresshardware (MAC) address of the main interface of the terminal. This field is important! Without a correct value the nearest printer won't work!
Terminal nameName of the terminal. Could for example be the terminal's DNS name or a name following a naming scheme that identifies the terminal.
LocationWhich of the locations, entered in the Locations module, this terminal belongs to.

It is also possible to add a printer to a terminal in the terminal module. This can be used if a terminal has its own printer or is closer to another printer than the ones assigned to this terminals location. You should use this feature moderately since it may cause more administration.

To add a printer you do exactly as in the Locations menu. Click the Add printer button, select the printer in the pop-up menu and then press Save to make sure that the settings are stored. To delete it, check the relevant Delete checkbox(es) for the printer(s) you wish to remove, and click Save .

17.2.5.2.  Locations

To edit a location, click on its name in the list.

To add a new location to the list you press the Add location button. This will bring up an empty location edit form. See Figure 17.5 for an example.

Figure 17.5.  New Location Form

New Location Form

Fill the Name and Description fields with relevant information. Check the checkbox if this location is to be used for unknown terminals when using the printer access control feature (see Section 5.5, “ Printer Access Control ” for details).

To save changes, press the Save button. When you have pressed the Save button you will see that the Name field will change from being an editable field to become a static text label. To assure data integrity between the modules you aren't allowed to change the name of an item after it's added.

The Delete button deletes the currently viewed location, but only if the confirmation checkbox is also checked. The Add Printer button will add a new field to the form, a drop-down menu with all possible printers. An example of this can be seen in Figure 17.6.

Figure 17.6.  Location Details With Printer

Location Details With Printer

The Printer field above has the printer europa selected. Remember to save the changes if you change printer! You can assign more printers to this location by clicking Add printer again to bring up another printer line. To remove a printer you select the Delete checkbox corresponding to the printer(s) you want to delete, and click Save to apply the changes. The printer(s) will disappear.

Note

Printers contains entries for all available printers. These entries are just shadows of the real CUPS (Common Unix Printing System) printer system entries. This means that you first need the printers to be installed in the CUPS printer system and then added to this list.

17.2.6.  The Desktop Customizer Module

The ThinLinc Desktop Customizer is described more fully in its own chapter, Chapter 18, Building custom Linux desktops with the ThinLinc Desktop Customizer . Links to sections of this chapter pertaining to the respective menus of the Desktop Customizer Module are provided below for convenience.

17.2.6.1.  Application Groups

For information on configuring Application Groups using TLDC, see Section 18.2.5, “ Defining Application Groups ”

17.2.6.2.  Applications (Manual)

For information on configuring Manual Applications using TLDC, see Section 18.2.3, “ Handling Applications ”

17.2.6.3.  Applications (System)

For information on configuring System Applications using TLDC, see Section 18.2.1.1, “ Applications ”

17.2.6.4.  Menu Structure

For information on configuring Menu Structures using TLDC, see Section 18.2.4, “ Defining a Menu Structure ”