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- support having override PerlSetVar set in loncapa_apache_local*.conf

    1: # The LearningOnline Network with CAPA
    2: # Configuration file reader
    3: #
    4: # $Id: Configuration.pm,v 1.14 2007/08/30 20:19:35 albertel Exp $
    5: #
    6: #
    7: # Copyright Michigan State University Board of Trustees
    8: #
    9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
   10: #
   11: # LON-CAPA is free software; you can redistribute it and/or modify
   12: # it under the terms of the GNU General Public License as published by
   13: # the Free Software Foundation; either version 2 of the License, or
   14: # (at your option) any later version.
   15: #
   16: # LON-CAPA is distributed in the hope that it will be useful,
   17: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   19: # GNU General Public License for more details.
   20: #
   21: # You should have received a copy of the GNU General Public License
   22: # along with LON-CAPA; if not, write to the Free Software
   23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   24: #
   25: # /home/httpd/html/adm/gpl.txt
   26: #
   27: # http://www.lon-capa.org/
   28: #
   29: # YEAR=2002
   30: #
   31: ###
   32: 
   33: # POD documentation is at the end of this short module.
   34: 
   35: package LONCAPA::Configuration;
   36: 
   37: $VERSION = sprintf("%d.%02d", q$Revision: 1.14 $ =~ /(\d+)\.(\d+)/);
   38: 
   39: use strict;
   40: 
   41: my @confdirs=('/etc/httpd/conf/','/etc/apache2/');
   42: 
   43: # ------------------- Subroutine read_conf: read LON-CAPA server configuration.
   44: # This subroutine reads PerlSetVar values out of specified web server
   45: # configuration files.
   46: sub read_conf {
   47:     my (@conf_files)=@_;
   48:     my (%perlvar,%configdirs);
   49:     foreach my $filename (@conf_files,'loncapa_apache.conf') {
   50:         my $configdir = '';
   51:         $configdirs{$filename} = [@confdirs];
   52:         while ($configdir eq '' && @{$configdirs{$filename}} > 0) {
   53:             my $testdir = shift(@{$configdirs{$filename}});
   54:             if (-e $testdir.$filename) {
   55:                 $configdir = $testdir;
   56:             }
   57:         }
   58:         if ($configdir eq '') {
   59:             die("Couldn't find a directory containing $filename");
   60:         }
   61: 	&process_file($configdir.$filename,\%perlvar);
   62: 	if ($filename eq 'loncapa_apache.conf') {
   63: 	    my @files = glob($configdir.'loncapa_apache_local*.conf');
   64: 	    foreach my $file (@files) {
   65: 		&process_file($file,\%perlvar);
   66: 	    }
   67: 	}
   68:     }
   69:     return (\%perlvar);
   70: }
   71: 
   72: # --------------- Subroutine process_file: helper routine 
   73: # This subroutine does the actual file reading and reads PerlSetVar discovery
   74: # specified file, arguments are the filename and a ref to a hash to
   75: # place the values in
   76: sub process_file {
   77:     my ($file,$perlvar) = @_;
   78:     open(my $config,'<',$file) or
   79: 	die("Can't read $file");
   80:     while (my $configline=<$config>) {
   81: 	if ($configline =~ /^[^\#]*PerlSetVar/) {
   82: 	    my ($unused,$varname,$varvalue)=split(/\s+/,$configline);
   83: 	    chomp($varvalue);
   84: 	    $perlvar->{$varname}=$varvalue;
   85: 	}
   86:     }
   87:     close($config);
   88: }
   89: 
   90: #---------------------- Subroutine read_hosts: Read a LON-CAPA hosts.tab
   91: # formatted configuration file.
   92: #
   93: my $RequiredCount = 5;		# Required item count in hosts.tab.
   94: my $DefaultMaxCon = 5;		# Default value for maximum connections.
   95: my $DefaultIdle   = 1000;       # Default connection idle time in seconds.
   96: my $DefaultMinCon = 0;          # Default value for minimum connections.
   97: sub read_hosts {
   98:     my $Filename = shift;
   99:     my %HostsTab;
  100:     
  101:     open(CONFIG,'<'.$Filename) or die("Can't read $Filename");
  102:     while (my $line = <CONFIG>) {
  103: 	if (!($line =~ /^\s*\#/)) {
  104: 	    my @items = split(/:/, $line);
  105: 	    if(scalar @items >= $RequiredCount) {
  106: 		if (scalar @items == $RequiredCount) { # Only required items:
  107: 		    $items[$RequiredCount] = $DefaultMaxCon;
  108: 		}
  109: 		if(scalar @items == $RequiredCount + 1) { # up through maxcon.
  110: 		    $items[$RequiredCount+1] = $DefaultIdle;
  111: 		}
  112: 		if(scalar @items == $RequiredCount + 2) { # up through idle.
  113: 		    $items[$RequiredCount+2] = $DefaultMinCon;
  114: 		}
  115: 		{
  116: 		    my @list = @items; # probably not needed but I'm unsure of 
  117: 		    # about the scope of item so...
  118: 		    $HostsTab{$list[0]} = \@list; 
  119: 		}
  120: 	    }
  121: 	}
  122:     }
  123:     close(CONFIG);
  124:     my $hostref = \%HostsTab;
  125:     return ($hostref);
  126: }
  127: 
  128: 1;
  129: __END__
  130: 
  131: =pod
  132: 
  133: =head1 NAME
  134: 
  135: B<LONCAPA::Configuration> - configuration file reader
  136: 
  137: =head1 SYNOPSIS
  138: 
  139:  use lib '/home/httpd/lib/perl/';
  140:  use LONCAPA::Configuration;
  141: 
  142:  LONCAPA::Configuration::read_conf('loncapa.conf');
  143:  LONCAPA::Configuration::read_hosts(filename);
  144: 
  145: =head1 DESCRIPTION
  146: 
  147: Many different parts of the LON-CAPA software need to reads in the
  148: machine-specific configuration information.  These included scripts
  149: controlling the TCP/IP layer (e.g. F<lonc> and F<lond>), testing scripts
  150: (e.g. test_weblayer.pl and sqltest.pl), and utility scripts
  151: (e.g. clusterstatus.pl and metadata_keywords.pl).
  152: 
  153: The following methods are available:
  154: 
  155: =over 4
  156: 
  157: =item $perlvarref = LONCAPA::Configuration::read_conf( @filename_list );
  158: 
  159: On a typical LON-CAPA server, the filename list argument will consist of
  160: just one element, "loncapa.conf".
  161: 
  162: If there are multiple elements within the filename list, then these
  163: filenames are processed consecutively.
  164: 
  165: A hash reference is returned and consists of those values which
  166: have been initialized from the configuration filenames indicated
  167: in the arguments.
  168: 
  169: If multiple file names define the same hash key, then priority is
  170: given toward the B<last> file name processed.
  171: 
  172: =back
  173: 
  174: =over 4
  175: =item $hostinfo = LONCAPA::Configuration::read_hosts(filename);
  176: 
  177:   The parameter is the name of a file in hosts.tab form.  The file is read and
  178: parsed.  The return value is a reference to a hash.   The hash is indexed by
  179: host and each element of the has is in turn a reference to an anonymous list
  180: containing:
  181: 
  182: =over 4
  183: =item host
  184:    The loncapa hostname of the system. (This may be different than the 
  185:    network hostname, see below).
  186: =item domain
  187:    The loncapa domain in which the host lives.
  188: =item role
  189:     The role of the system, currently allowed values are access for an
  190:     access server and library for a library server.
  191: =item dns
  192:     The DNS hostname of the system. 
  193: =item ip
  194:     The IP address corresponding to the dns hostname of the system.
  195: =item maxconn 
  196:     The maximum number of connections this system should hold to the
  197:     target system's lond.  If the file has no value, a default is supplied
  198:     here by the function.
  199: =item idle
  200:     The number of seconds the oldest idle connection can be idle before it
  201:     should be adaptively dropped.  If the file has no value, a default
  202:     is supplied by the function.
  203: =item mincon
  204:     The minimum number of connections this system should hold to the
  205:     target system's lond.  If the file has no value, a default is supplied by
  206:     the funciton.
  207: 
  208: =back
  209: 
  210: =back
  211: 
  212: 
  213: 
  214: =head1 AUTHORS
  215: 
  216: This library is free software; you can redistribute it and/or
  217: modify it under the same terms as LON-CAPA itself.
  218: 
  219: =cut