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May 7, 2010 01:42
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| #!/usr/bin/perl | |
| =pod | |
| slavepush.pl | |
| Author: Ted Behling <ted@tedb.us> | |
| Copyright 2010 Hargray Communications | |
| See license below | |
| For administrators of the BIND DNS server, this script can be used to keep the configurations of slave BIND servers in sync with the master. This will take a BIND configuration file, extract out the "zone" lines, and render a new configuration file suitable for use on a slave BIND server. | |
| Example invocation: | |
| slavepush.pl --sourcefile /var/named/named.conf.domains --masters 1.1.1.1 --targetfile /var/named/named.conf.domains --rndc /usr/sbin/rndc --fileprefix domains/ --ssh root@slave1 --ssh root@slave2 | |
| For example, a --sourcefile that contains: | |
| zone "example.com" IN { | |
| type master; | |
| file "example.com"; | |
| }; | |
| zone "example.net" IN { | |
| type master; | |
| file "example.net"; | |
| }; | |
| ...will push to the servers specified by --ssh a config file that contains: | |
| zone "example.com" IN { type slave; masters 1.1.1.1; file "domains/example.com"; }; | |
| zone "example.net" IN { type slave; masters 1.1.1.1; file "domains/example.net"; }; | |
| This script just cares about the zone name; the rest of the "master" configuration is discarded. | |
| Developer notes: | |
| 1. read file specified by --sourcefile; get list of zones by grepping for "zone" lines; | |
| exclude lines that have comment of /* !NOSLAVEPUSH! */ | |
| 2. Generate "slave" BIND config file fragment, with the "masters" IP specified by --masters flag | |
| 3. SSH to server specified by --ssh flag(s); | |
| 4. over SSH, write to file --targetfile + ".candidate" | |
| 5. over SSH, "diff -q targetfile targetfile.candidate"; | |
| if exit code 1, do "mv targetfile.candidate targetfile; rndc reconfig"; else "rm targetfile.candidate" | |
| =cut | |
| use strict; | |
| use warnings; | |
| use Getopt::Long; | |
| # Config params are global variables | |
| our ($sourcefile, $masters, $targetfile, $fileprefix, $rndc, @ssh) = ('', '', '', '', 'rndc', ()); | |
| GetOptions("sourcefile=s" => \$sourcefile, | |
| "masters=s" => \$masters, | |
| "targetfile=s" => \$targetfile, | |
| "fileprefix=s" => \$fileprefix, | |
| "rndc=s" => \$rndc, | |
| "ssh=s" => \@ssh, | |
| ); | |
| #print "sourcefile $sourcefile masters $masters targetfile $targetfile fileprefix $fileprefix ssh @ssh\n"; | |
| sub target_contents { | |
| open(my $source, '<', $sourcefile) or die $!; | |
| my $target_contents = ''; | |
| while(<$source>) { | |
| # e.g. zone "example.com" IN { | |
| next unless /^\s*zone "([^"]+)"/ && ! /!NOSLAVEPUSH!/; | |
| my $zone = $1; | |
| my $masters_config = $masters ? "masters { $masters; };" : ''; | |
| $target_contents .= "zone \"$zone\" IN { type slave; $masters_config file \"$fileprefix$zone\"; };\n"; | |
| } | |
| close $source; | |
| return $target_contents; | |
| } | |
| sub push_target_to_ssh { | |
| my ($ssh, $target_contents) = (shift, shift); | |
| my $targetfile_candidate = $targetfile . '.candidate'; | |
| my $scp_command = "ssh $ssh 'cat > $targetfile_candidate'"; | |
| print "Writing tempfile over SSH...\n"; | |
| print "$scp_command\n"; | |
| open(my $sshwrite, '|-', $scp_command) or die "can't ssh to write file: $!"; | |
| print $sshwrite $target_contents; | |
| close $sshwrite; | |
| # diff will return exit value of 0 if unchanged, 1 if changed | |
| system "ssh", $ssh, "diff -q $targetfile $targetfile_candidate"; | |
| my $diff_exit_value = $? >> 8; | |
| if ($diff_exit_value) { | |
| print "New slave config file is different; overwriting old file and doing $rndc reconfig...\n"; | |
| system "ssh", $ssh, "mv '$targetfile_candidate' '$targetfile' && $rndc reconfig"; | |
| } else { | |
| print "New slave config file is unchanged; deleting tempfile...\n"; | |
| system "ssh", $ssh, "rm '$targetfile_candidate'"; | |
| } | |
| } | |
| print "Generating slave config file...\n"; | |
| my $target_contents = target_contents(); | |
| for my $ssh (@ssh) { | |
| push_target_to_ssh($ssh, $target_contents); | |
| } | |
| print "Done.\n"; | |
| =pod | |
| The MIT License | |
| Copyright (c) 2010 Hargray Communications | |
| Permission is hereby granted, free of charge, to any person obtaining a copy | |
| of this software and associated documentation files (the "Software"), to deal | |
| in the Software without restriction, including without limitation the rights | |
| to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
| copies of the Software, and to permit persons to whom the Software is | |
| furnished to do so, subject to the following conditions: | |
| The above copyright notice and this permission notice shall be included in | |
| all copies or substantial portions of the Software. | |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
| AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
| OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
| THE SOFTWARE. | |
| =cut |
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