Map Host Names

In several points in the systems, it is useful to get the host name for a checkout, for a job, for a daemon, etc. Since every machine may be known by different names, it is important to provide the expert user with the ability to map host names to some canonical form of the host name.

This is accomplished by overriding the procedure mapHostName which in its default implementation simply returns the short host name in all lower case. (Note, a fully qualified hostname is converted to its short name.)

# Default definition of mapHostName in vovutils.tcl 
proc mapHostName { host { defaultName "" } { context "" } } {
   set shortHost [ string tolower [ lindex [split $host .] 0 ] ]
   return $shortHost 
}

The procedure can be overridden using the file hostmap.tcl in the .swd directory. This file is read by calling the procedure mapHostNameInit.

mapHostNameInit <context>

where context is an optional parameter to specify any string that sets the context of the host mapping calls. If no context is provided, it defaults to an empty string.

Further, a context can also be specified as an argument to mapHostName procedure.

The default implementation of mapHostName does not use the context. However, a custom implementation specified in hostmap.tcl may either use the context provided in calling it, or it can access the context set in mapHostNameInit by using the variable vovutils(hostmap,context):

# Example of hostmap.tcl
proc mapHostName { host { defaultName "" } { context "" } } {
   global vovutils
   switch -glob -- $host {
       "lnxBG*"           { return [string tolower $host] }
       "lnx*.company.com" { return [lindex  [split $host .] 0] }
       "localhost" {
           if { $vovutils(hostmap,context) eq "LM" } {
                return $defaultName
           } elseif { $context eq "NC-USA" } {
                return "mynchostname"
           }
       }
       default           { return $host }
   }
}

The mapHostName procedure is used in Allocator:

vovlalm: Used to sample Monitor data from Allocator. This script provides the nickname of the Monitor instance as the context on mapHostNameInit, and also uses the Monitor instance's nickname as the context in the call to mapHostName.
vovlavtkncget (called by vovlanc): Used to sample Accelerator data from Allocator. This script provides the nickname of the Accelerator site as the context on mapHostNameInit, and also uses the Accelerator instance's nickname as the context in the call to mapHostName.

Also to be noted, in Monitor, is the use of the built-in procedure LMnormalizedName, which is used to eliminate non-ASCII characters from user names, host names, and feature names.