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Windows Services : H.4 Manual Installation
Copyright © 2003-2010 ZeroC, Inc.

H.4 Manual Installation

This section describes how to manually install and configure an Ice service using the IcePatch2 service as a case study. For the purposes of this discussion, we assume that Ice is installed in the directory C:\Ice. We also assume that you have administrative access to your system, which is required by many of the installation steps discussed in this section.

Selecting a User Account

The IcePatch2 service can run in a regular user account, therefore we will follow the recommendation on page 2004 and use the Local Service account.

Preparing a Directory

The service needs a directory in which to store the files that it distributes to clients. A common mistake is assuming that a service will be able to access a file or directory that you created using your current account, which is likely to cause the service to fail in a way that is difficult to diagnose. To prevent such failures, we will ensure that the directory has the necessary permissions for the service to access it while running in the Local Service account.

Selecting a Directory

The directory tree for our IcePatch2 service is shown below:
C:\Documents and Settings\
  LocalService\
    Local Settings\
      Application Data\
        ZeroC\
          icepatch2\
            data\
Note that this tree applies to Windows XP and Windows Server 2003, and is locale dependent. On Windows Vista, we would use the following tree instead:
C:\Windows\
  ServiceProfiles\
    LocalService\
      AppData\
        Local\
          ZeroC\
            icepatch2\
              data\
For this example, we will use the Windows XP directory tree.

Creating the Directory

Since Local Service is a built-in account, its user directory should already exist and have the proper access rights.1 If the directory does not exist, we can create it in a command window with the following steps:
cd \Documents and Settings
mkdir LocalService
At this point we could create the rest of the directory hierarchy. However, a newly-created directory inherits the privileges of its enclosing directory, and we have not yet modified the privileges of the LocalService directory to grant access to the Local Service account. At present, the privileges of the LocalSer­vice directory are inherited from Documents and Settings and require modification. In general, it is better to establish the necessary access rights on the parent directory prior to creating any subdirectories, so we will modify the LocalService directory first.
On all Windows systems, we can use the command-line utility cacls. The following command does what we need:
cacls LocalService /G "Local Service":F Administrators:F
By omitting the /E option to cacls, we have replaced all of the prior access rights on the directory with the rights given in this command. As a result, the Local Service account and anyone in the Administrators group are granted full access to the directory, while all others are forbidden. (We grant full access to the Administrators group because presumably someone other than the Local Service account will need to manage the subdirectory, create the configuration file, an so on). You can verify the directory's current privilege settings by running cacls without options:
cacls LocalService
Now we can create the remaining subdirectories, and they will automatically inherit the access rights established for the LocalService directory:
cd LocalService
mkdir "Local Settings\Application Data\ZeroC\icepatch2\data"
If you want to further restrict access to files or subdirectories, you can modify them as necessary using the cacls utility. Note however that certain actions may cause a file to revert back to the access rights of its enclosing directory. For example, modifying a file using a text editor is often the equivalent of erasing the file and recreating it, which discards any access rights you may have previously set for the file.
On some versions of Windows XP, and on Windows Server 2003 and Windows Vista, you can manage privilege settings interactively using Windows Explorer. For example, right click on the LocalService directory, select Prop­erties, and select the Security tab. Next select Advanced and Edit, uncheck “Include inheritable permissions from this object’s parent,” and select Copy. Remove all permission entries, then add entries for Local Service and the Admin­istrators group and grant Full Control to each.

Populating the Directory

Now you can copy the files that will be distributed to clients into the data subdi­rectory. The new files should inherit the access rights of their enclosing directory. For the sake of discussion, let us copy some Slice files from the Ice distribution into the data directory:
cd "Local Settings\Application Data\ZeroC\icepatch2\data"
copy \Ice\slice\Ice\*.ice
Next we need to run icepatch2calc to prepare the directory for use by the IcePatch2 service:
icepatch2calc .

Configuration File

IcePatch2 requires a minimal set of configuration properties. We could specify them on the service’s command line, but if we later want to modify those proper­ties we would have to reinstall the service. Defining the properties in a file simpli­fies the task of modifying the service’s configuration.
Our IcePatch2 configuration is quite simple:
IcePatch2.Directory=C:\Documents and Settings\LocalService\
Local Settings\Application Data\ZeroC\icepatch2\data
IcePatch2.Endpoints=tcp -p 10000
The IcePatch2.Directory property specifies the location of the server’s data directory, which we created in the previous section.
We will save our configuration properties into the following file:
C:\Ice\config\icepatch2.cfg
We must also ensure that the service has permission to access its configuration file. The Ice run time never modifies a configuration file, therefore read access is sufficient. The configuration file likely already has the necessary access rights, which we can verify using the cacls utility that we described in the previous section:
cacls C:\Ice\config\icepatch2.cfg

Creating the Service

We will use Microsoft’s Service Control (sc) utility2 in a command window to create the service. Our first sc command does the majority of the work (the command is formatted for readability but must be typed on a single line):
sc create icepatch2
  binPath= "C:\Ice\bin\icepatch2server.exe
    --Ice.Config=C:\Ice\config\icepatch2.cfg --service icepatch2"
  DisplayName= "IcePatch2 Server" start= auto
  obj= "NT Authority\LocalService" password= ""
There are several important aspects of this command:
• The service name is icepatch2. You can use whatever name you like, as long as it does not conflict with an existing service. Note however that this name is used in other contexts, such as in the --service option discussed below, therefore you must use it consistently.
• Following the service are several options. Note that all of the option names end with an equals sign and are separated from their arguments with at least one space.
• The binPath= option is required. We supply the full path name of the IcePatch2 server executable, as well as command-line arguments that define the location of the configuration file and the name of the service, all enclosed in quotes.
• The DisplayName= option sets a friendly name for the service.
• The start= option configures the start up behavior for the service. We used the argument auto to indicate the service should be started automatically when Windows boots.
• The obj= option selects the user account in which this service runs. As explained on page 2004, the Local Service account is appropriate for most services.
• The password= option supplies the password associated with the user account indicated by obj=. The Local Service account has an empty password.
The sc utility should report success if it was able to create the service as speci­fied. You can verify that the new service was created with this command:
sc qc icepatch2
Alternatively, you can start the Services administrative control panel and inspect the properties of the IcePatch2 service.
If you start the control panel, you will notice that the entry for IcePatch2 does not have a description. To add a description for the service, use the following command:
sc description icepatch2 "IcePatch2 file server"
After refreshing the list of services, you should see the new description.

Creating the Event Log

By default, programs such as the IcePatch2 service that utilize the Service class (see Section 8.3.2) log messages to the Application event log. Below we describe how to prepare the Windows registry for the service’s default behavior, and we also show how to use a custom event log instead. We make use of Microsoft’s Registry (reg) utility to modify the registry, although you could also use the interactive regedit tool. As always, caution is recommended whenever you modify the registry.

Using the Application Log

We must configure an event log source for events to display properly. The first step is to create a registry key with the name of the source. Since the Service class uses the service name as the source name by default, we add the key icepatch2 as shown below:
reg add HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
Application\icepatch2
Inside this key we must add a value that specifies the location of the Ice run time DLL:
reg add HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
Application\icepatch2 /v EventMessageFile /t REG_EXPAND_SZ
/d C:\Ice\bin\ice34.dll
We will also add a value indicating the types of events that the source supports:
reg add HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
Application\icepatch2 /v TypesSupported /t REG_DWORD /d 7
The value 7 corresponds to the combination of the following event types:
• EVENTLOG_ERROR_TYPE
• EVENTLOG_WARNING_TYPE
• EVENTLOG_INFORMATION_TYPE
You can verify that the registry values have been defined correctly using the following command:
reg query HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
Application\icepatch2
Our configuration of the event log is now complete.

Changing the Source Name

Using the configuration described in the previous section, events logged by the IcePatch2 service are recorded in the event log using the source name icepatch2. If you prefer to use a source name that differs from the service name, you can replace icepatch2 in the registry commands with the name of your choosing, but you must also add a matching definition for the property Ice.EventLog.Source to the service’s configuration file.
For example, to use the source name Ice File Patching Service, you would add the registry key as shown below:
reg add "HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
Application\Ice File Patching Service"
The commands to add the EventMessageFile and TypesSupported values must be modified in a similar fashion. Finally, add the following configura­tion property to icepatch2.cfg:
Ice.EventLog.Source=Ice File Patching Service

Using a Custom Log

You may decide that you want your services to record messages into an applica­tion-specific log instead of the Application log that is shared by other unre­lated services. As an example, let us create a log named MyApp:
reg add "HKLM\SYSTEM\CurrentControlSet\Services\EventLog\MyApp"
Next we add a subkey for the IcePatch2 service. As described in the previous section, we will use a friendlier source name:
reg add "HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
MyApp\Ice File Patching Service"
Now we can define values for EventMessageFile and TypesSupported:
reg add "HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
MyApp\Ice File Patching Service" /v EventMessageFile
/t REG_EXPAND_SZ /d C:\Ice\bin\ice34.dll

reg add "HKLM\SYSTEM\CurrentControlSet\Services\EventLog\
MyApp\Ice File Patching Service" /v TypesSupported /t REG_DWORD /d 7
Finally, we define Ice.EventLog.Source in the IcePatch2 service’s configu­ration file:
Ice.EventLog.Source=Ice File Patching Service
Note that you must restart the Event Viewer control panel after adding the MyApp registry key in order to see the new log.

Registry Caching

The first time a service logs an event, Windows’ Event Log service caches the registry entries associated with the service’s source. If you wish to modify a service’s event log configuration, such as changing the service to use a custom log instead of the Application log, you should perform the following steps:
1. Stop the service.
2. Remove the unwanted event log registry key.
3. Add the new event log registry key(s).
4. Restart the system (or at least the Event Log service).
5. Start the service and verify that the log entries appear in the intended log.
After following these steps, open a log entry and ensure that it displays properly. If it does not, for example if the event properties indicate that the description of an event cannot be found, the problem is likely due to a misconfigured event source. Verify that the value of EventMessageFile refers to the correct location of the Ice run time DLL, and that the service is defining Ice.EventLog.Source in its configuration file (if necessary).

Starting the Service

We are at last ready to start the service. In a command window, you can use the sc utility:
sc start icepatch2
The program usually responds with status information indicating that the start request is pending. You can query the service’s status to verify that it started successfully:
sc query icepatch2
The service should now be in the running state. If it is not in this state, open the Event Viewer control panel and inspect the relevant log for more information that should help you to locate the problem. Even if the service started successfully, you may still want to use the Event Viewer to confirm that the service is using the log you expected.

Test the Service

Ice includes a graphical IcePatch2 client in the demo/IcePatch2/MFC direc­tory of the Ice distribution. Once you have built the client, you can use it to test that the service is working properly.

1
If you open C:\Documents and Settings in Windows Explorer, the LocalService directory may not be visible until you modify your folder options to show protected files and folders.

2
See http://support.microsoft.com/kb/251192 for more information about the SC utility.


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