taskd/taskd.pl

   1 #!/usr/bin/perl
   2 #
   3 # taskd - Clone repositories on request
   4 #
   5 # taskd is Girocco mirroring servant; it processes requests for clones
   6 # of given URLs received over its socket.
   7 #
   8 # When a request is received, new process is spawned that sets up
   9 # the repository and reports further progress
  10 # to .clonelog within the repository. In case the clone fails,
  11 # .clone_failed is touched and .clone_in_progress is removed.
  12
  13 # Protocol:
  14 # Alice sets up repository and touches .cloning
  15 # Alice opens connection to Bob
  16 # Alice sends project name through the connection
  17 # Bob opens the repository and sends back 0 if ok, error code otherwise
  18 # Bob closes connection
  19 # Alice polls .clonelog in case of 0.
  20 # If Alice reads "@OVER@" from .clonelog, it stops polling.
  21
  22 # Based on perlipc example.
  23
  24 use strict;
  25 use warnings;
  26
  27 use Girocco::Config;
  28 use Girocco::Project;
  29 use Socket;
  30
  31 $| = 1;
  32
  33 sub logmsg { print '['.(scalar localtime)."] $0 $$: @_\n" }
  34
  35 my $NAME = $Girocco::Config::chroot.'/etc/taskd.socket';
  36 my $uaddr = sockaddr_un($NAME);
  37
  38 socket(Server, PF_UNIX, SOCK_STREAM, 0) or die "socket: $!";
  39 unlink($NAME);
  40 bind(Server, $uaddr) or die "bind: $!";
  41 listen(Server, SOMAXCONN) or die "listen: $!";
  42 chmod 0666, $NAME or die "chmod: $!";
  43
  44
  45 use POSIX ":sys_wait_h";
  46 sub REAPER {
  47         my $child;
  48         my $waitedpid;
  49         while (($waitedpid = waitpid(-1, WNOHANG)) > 0) {
  50                 logmsg "reaped $waitedpid" . ($? ? " with exit $?" : '');
  51         }
  52         $SIG{CHLD} = \&REAPER;  # loathe sysV
  53 }
  54
  55 $SIG{CHLD} = \&REAPER;  # Apollo 440
  56
  57 sub spawn {
  58         my $coderef = shift;
  59
  60         my $pid = fork;
  61         if (not defined $pid) {
  62                 logmsg "cannot fork: $!";
  63                 return;
  64         } elsif ($pid) {
  65                 logmsg "begat $pid";
  66                 return; # I'm the parent
  67         }
  68
  69         open STDIN, "<&Client" or die "can't dup client to stdin";
  70         open STDOUT, ">&Client" or die "can't dup client to stdout";
  71         exit &$coderef();
  72 }
  73
  74 sub clone {
  75         my ($name) = @_;
  76         Girocco::Project::does_exist($name) or die "won't clone non-existing project $name";
  77         print STDERR "cloning $name\n";
  78         open STDOUT, ">".$Girocco::Config::reporoot."/".$name.".git/.clonelog" or die "cannot open clonelog: $!";
  79         open STDERR, ">&STDOUT";
  80         open STDIN, "</dev/null";
  81         exec $Girocco::Config::basedir.'/taskd/clone.sh', "$name.git" or die "exec failed: $!";
  82 }
  83
  84 while (1) {
  85         unless (accept(Client, Server)) {
  86                 logmsg "accept failed: $!";
  87                 next;
  88         }
  89         logmsg "connection on $NAME";
  90         spawn sub {
  91                 my $inp = <>;
  92                 chomp $inp;
  93                 my ($cmd, $arg) = $inp =~ /^([a-zA-Z0-9-]+)\s+(.*)$/;
  94                 if ($cmd eq 'clone') {
  95                         clone($arg);
  96                 } else {
  97                         die "unknown command: $cmd";
  98                 }
  99         };
 100         close Client;
 101         sleep 1;
 102 }