#!/usr/bin/perl

=pod

=head1 NAME

B<CHECKRPMS> - automated status report about RPMs on a system

=head1 SYNOPSIS

./CHECKRPMS

or

perl CHECKRPMS

=head1 DESCRIPTION

This file automates the usage of Martin Siegert's "check-rpms"
script.  It runs through a list of possible mirror sites
until it finds one with a reasonably good FTP connection.

=head2 Future directions

Eventually, this script may have a simple argument format
that allows the user to VIEW, DOWNLOAD, or AUTOUPDATE their
computer.  Or, this script may evolve into an interactive
series of steps:  For example, there may be questions like this:

=over 4

=item *

Do you want to (D)ownload or (A)utoupdate the RPMs
in the list above?

=item *

Specify a download location for the RPMs
(default=/tmp/update_my_rpms/)?

=back

Note that there are no current plans to automate a software upgrade of the
kernel.  This step should be performed by a qualified system administrator.

=head1 AUTHOR

Scott Harrison, sharrison@users.sourceforge.net, 2002

=cut

# =================================================== READ IN COMMAND ARGUMENTS
# ---------------------------------------------------- Process download option.
my $download=shift(@ARGV);
if ($download eq '--download')
  {
    if ($< != 0) # Download mode requires 'root'.
      {
        print('**** ERROR **** Download mode needs to be run as root'."\n");
	exit(1); # Exit with error status.
      }
    `rm -Rf /tmp/loncapa_rpm_updates`;
    $download='-v -dl -d /tmp/loncapa_rpm_updates'; # Part of check-rpms args.
  }
else
  {
    $download='';
  }

# =================================================== GENERAL INITIAL VARIABLES
# ---------------- The FTP servers (and their directory paths) to check against
my @serverpaths_to_try = 
  (
    'mirror.pa.msu.edu/linux/redhat/linux/updates/',
    'rufus.w3.org/linux/redhat/linux/updates/',
    'distro.ibiblio.org/pub/linux/distributions/redhat/updates/',
    'limestone.uoregon.edu/redhat/updates/',
    'opnsrc.support.compaq.com/linux/redhat/updates.redhat.com/',
  );

# --------------------------------------------------- Determine RedHat version.
my $RHversion = (split /\s/, `cat /etc/redhat-release`)[4]; # - 6.2 or 7.3 or ?

 # ------------------------------------------- Use check-rpms command this way.
my $checkcommand = 'check-rpms '.$download.' --rpmuser www -ftp';

my $FTPSERVER; # ------------------------- the server portion of the serverpath
my $FTPUPDATES; # ----------------------------- the actual update root location
my @rpms; # ---------------------------------- this will store the list of RPMs
my $goodoutput; # ------------------------------------ good stuff was returned!
my $reallygoodoutput; # ------------------------------- you are 100% up-to-date

# ----------------------------------------- Find the check-rpms script location
if (-e './check-rpms')
  {
    $commandpre='perl ./'; # Use the check-rpms in the current directory.
  }
elsif (-e 'loncom/build/check-rpms')
  {
    $commandpre='perl loncom/build/'; # Use check-rpms int he loncom/build dir.
  }
else # Cannot find check-rpms, so abort.
  {
    die("**** ERROR **** CANNOT FIND THE check-rpms SCRIPT\n");
  }

# Define the overall check-rpms invocation based on the path to the check-rpms
# command.
$checkcommand = $commandpre.$checkcommand;

# ============== Go through all the servers until a decent connection is found.
# Notify user of current action.
print(<<END);
THIS SCRIPT IS NOW PROBING SEVERAL FTP SERVERS....
PLEASE BE PATIENT, THIS MAY TAKE A FEW MINUTES.
END

SERVERLOOP: foreach my $serverpath (@serverpaths_to_try)
  {
    $serverpath=~/^(.*?)\//; # Pattern match the ip name.
    $FTPSERVER=$1; # Set to the ip name.
    print "Trying $FTPSERVER...\n"; # Notify user of attempts with the ip name.
    `ping -c 1 $FTPSERVER 2>/dev/null`; # Ping ftp server (are you out there?).
    if ($?==0) # If the ftp server can be pinged.
      {
	print "$FTPSERVER found...\n"; # Tell user the ftp server is found.
	`ncftpls ftp://$FTPSERVER`; # Try to access server with ftp protocol.
	if ($?==0) # If the ftp server can be accessed with the ftp protocol.
          {
	    $FTPUPDATES="$serverpath$RHversion/en/os"; # The full update path.
	    # Print the check-rpms command that will be executed.
	    print($checkcommand.' '.$FTPUPDATES."\n");
	    if ($download) # Was CHECKRPMS run in download mode?
              {
		$|=1; # Try to send things immediately to stdout; err umm....
		# Tell the user about the /tmp/loncapa_rpm_updates directory.
		print('**** NOTE ****'.
		      'To check the status of the download, you can '.
		      'periodically inspect the contents of the '.
		      '/tmp/loncapa_rpm_updates directory.  '.
		      'Please be patient; this download may take a while.'.
		      "\n");
		# Do the download.
		print(`$checkcommand $FTPUPDATES 2>\&1`);
		# Tell the user about what action they need to take with the
		# downloaded RPMs.
		print('You may now wish to visit the /tmp/loncapa_rpm_updates'.
		      ' directory and upgrade the RPMs.  '."\n".
		      'If this is a critical server (it is currently being'.
		      ' used for classes) and you do not know how to upgrade'.
		      ' RPMs, you should consult someone who has experience '.
		      'with the "rpm" command.'."\n");
		exit(0); # Assume everything is okay and exit.
	      }
	    @rpms=`$checkcommand $FTPUPDATES 2>\&1`; # Read in list of RPMs.
	    # Create a text string that can be pattern matched.
	    my $rpmtext=join('',@rpms);
	    if ($rpmtext=~/You do not seem to have a/) # No www?
              {
		print "You do not have a 'www' user on your system.\n".
		    "Please add this user and try this command again.\n";
		exit(1);
	      }
	    if ($rpmtext=~/This account is currently not/) # ------------ uh-oh
	      {
		print "...strange error, moving on ($FTPSERVER)\n";
	      }
	    else # --------------------------------------- the output is "good"
	      {
		$goodoutput=$rpmtext;
		unless (@rpms) # If there are no RPMs to update.
		  {
		    $reallygoodoutput=<<END;
**** NOTE **** All RPMS on your system appear to be up to date.
END
		  }
		last SERVERLOOP;
	      }
	  }
	print('...cannot establish an ftp session with '.$FTPSERVER."\n");
      }
    else
      {
	print "...cannot find $FTPSERVER on the network\n";
      }
  }
if (!$goodoutput) # If never received any useable output, assume "no server".
  {
    print "**** ERROR **** Cannot find a working ftp server.\n";
    exit(1);
  }
elsif ($reallygoodoutput) # Everything is peachy keen and up-to-date already.
  {
    print $reallygoodoutput;
  }
else # There are RPMs that need to be updated; show list to user.
  {
    my $rpmcount=scalar(@rpms); # Count up size of RPM list.
    print(<<END); # Print out an advisory warning to user.
**** WARNING **** You need to update at least $rpmcount RPMS shown in
the list below.  THIS IS IMPORTANT FOR SECURITY.

END
    print $goodoutput; # Output the RPM list.
    print(<<END); # Output instructions to user about taking action.

Please visit ftp://$FTPUPDATES
and download the RPMS you need.
For instructions on working with (and upgrading) RPMS, please
visit http://www.rpm.org/max-rpm/.
To automatically download these RPMs to /tmp/loncapa_rpm_updates/,
run the CHECKRPMS command as "./CHECKRPMS --download"
END
  }