#
# git caching proxy
+# Suitable only for exposing to semi-trusted clients: clients are not
+# supposed to be able to take over the server. However, clients can
+# probably deny service to each other because the current
+# implementation is not very good at handling various out-of-course
+# situations (notably, clients which are too slow).
+
# usage: run it on some port, and then clone or fetch
# "git://<realhost>:<realport>/<real-git-url>[ <options>]"
# where <real-git-url> is http://<host>/... or git://<host>/...
# fetch=try use what is in the cache if the fetch/clone fails
# timeout=<seconds> length of time to allow for fetch/clone
+# example inetd.conf line:
+# 9419 stream tcp nowait git-cache /usr/bin/git-cache-proxy git-cache-proxy
+# you'll need to
+# adduser git-cache
+# mkdir /var/cache/git-cache-proxy
+# chown git-cache /var/cache/git-cache-proxy
+
+# git-cache-proxy
+# Copyright 2010 Tony Finch
+# Copyright 2013,2014 Ian Jackson
+#
# git-cache-proxy is free software; you can redistribute it and/or
# modify them under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 3, or (at
# your option) any later version.
-#
+#
# git-cache-proxy is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
our $us = 'git-cache-proxy';
+our $debug = 0;
+our $housekeepingeverydays = 1;
+our $treeexpiredays = 21;
+our $fetchtimeout = 1800;
+our $maxfetchtimeout = 3600;
+our $cachedir = '/var/cache/git-cache-proxy';
+our $housekeepingonly = 0;
+
#---------- error handling and logging ----------
# This is a bit fiddly, because we want to catch errors sent to stderr
sub logm ($$) {
my ($pri, $msg) = @_;
+ return if $pri eq 'debug' && !$debug;
if ($client eq '(local)') {
print STDERR "$us: $pri: $msg\n" or die $!;
- exit 1;
+ return;
}
ensurelog();
my $mainmsg = sprintf "%s-%s: %s", $server, $client, $msg;
my $wholemsg = sprintf("%s [%d] %s: %s\n",
strftime("%Y-%m-%d %H:%M:%S Z", gmtime),
$$,
- $pri,
+ $pri eq 'err' ? 'error' : $pri,
$mainmsg);
print $log $wholemsg;
} else {
- syslog $pri, $mainmsg;
+ syslog $pri, "%s", "$pri $mainmsg";
}
}
#---------- argument parsing ----------
-our $housekeepingthreshdays = 1;
-our $treeexpiredays = 21;
-our $fetchtimeout = 1800;
-our $maxfetchtimeout = 3600;
-our $cachedir = '/var/cache/git-cache-proxy';
-
for (;;) {
last unless @ARGV;
last unless $ARGV[0] =~ m/^-/;
$_ = shift @ARGV;
for (;;) {
last unless m/^-./;
- if (s/^-L(.*)$//) {
+ if (s/^-H/-/) {
+ $housekeepingonly++;
+ } elsif (s/^-D/-/) {
+ $debug++;
+ } elsif (s/^-L(.*)$//) {
my $logfile = $_;
open STDERR, ">>", $logfile or fail "open $logfile: $!";
$log = \*STDERR;
} elsif (s/^-d(.*)$//) {
$cachedir = $1;
- } elsif (s/^--(maxfetchtimeout|fetchtimeout)=(\d+)$//) {
- ${ $::{$1} } = $2;
+ } elsif (s/^--( max-fetch-timeout
+ | fetch-timeout
+ | tree-expire-days
+ | housekeeping-interval-days
+ )=(\d+)$//x) {
+ my $vn = $1;
+ $vn =~ y/-//d;
+ die $vn unless defined ${ $::{$vn} };
+ ${ $::{$vn} } = $2;
} else {
fail "bad usage: unknown option `$_'";
}
!@ARGV or fail "bad usage: no non-option arguments permitted";
-#---------- main program ----------
+#---------- utility functions ----------
-chdir $cachedir or fail "chdir $cachedir: $!";
-
-our ($service,$specpath,$spechost,$subdir);
-our ($tmpd,$gitd,$lock);
-our ($fetch,$url);
+sub lockfile ($$$) {
+ my ($fh, $fn, $flockmode) = @_;
+ my $what = $fn.(($flockmode & ~LOCK_NB) == LOCK_SH ? " (shared)" : "");
+ for (;;) {
+ close $fh;
+ open $fh, '+>', $fn or fail "open/create $fn for lock: $!";
+ logm 'debug', "lock $what: acquiring";
+ if (!flock $fh, $flockmode) {
+ if ($flockmode & LOCK_NB && $! == EWOULDBLOCK) {
+ return 0; # ok then
+ }
+ fail "lock $what: $!";
+ }
+ stat $fh or fail "stat opened $fn: $!";
+ my $fh_ino = ((stat _)[1]);
+ if (!stat $fn) {
+ $! == ENOENT or fail "stat $fn: $!";
+ next;
+ }
+ my $fn_ino = ((stat _)[1]);
+ if ($fn_ino == $fh_ino) {
+ logm 'debug', "lock $what: acquired";
+ return 1;
+ }
+ logm 'debug', "lock $what: deleted, need to loop again";
+ # oh dear
+ }
+}
sub xread {
my $length = shift;
return $buffer;
}
+#---------- main program ----------
+
+chdir $cachedir or fail "chdir $cachedir: $!";
+
+our ($service,$specpath,$spechost,$subdir);
+our ($tmpd,$gitd,$lock);
+our ($fetch,$url);
+
sub servinfo ($) {
my ($msg) = @_;
logm 'info', "service `$specpath': $msg";
$fetch = 0;
} elsif (m/^fetch=must$/) {
$fetch = 2; # the default
- } elsif (m/^timeout=(\d+)$/) {
+ } elsif (m/^timeout=(\d+)$/ && $1 >= 1) {
$fetchtimeout = $1 <= $maxfetchtimeout ? $1 : $maxfetchtimeout;
} elsif ($must) {
gitfail "unknown/unsupported option `$_'";
}
sub clonefetch () {
- open LOCK, "+>", $lock or fail "open/create $lock: $!";
- flock LOCK, LOCK_EX or fail "lock exclusive $lock: $!";
+ lockfile \*LOCK, $lock, LOCK_EX;
- my $exists = stat $gitd;
- $exists or $!==ENOENT or fail "stat $gitd: $!";
+ my $exists = lstat $gitd;
+ $exists or $!==ENOENT or fail "lstat $gitd: $!";
our $fetchfail = '';
}
servinfo "sharing";
- flock LOCK, LOCK_UN or fail "unlock $lock: $!";
- flock LOCK, LOCK_SH or fail "lock shared $lock: $!";
- # actually, just relocking as shared would have the same semantics
- # but it's best to be explicit
+ lockfile \*LOCK, $lock, LOCK_SH; # NB releases and relocks
- if (chdir $gitd) {
+ if (stat $gitd) {
return 1;
}
- $!==ENOENT or fail "chdir $gitd: $!";
+ $!==ENOENT or fail "stat $gitd: $!";
# Well, err, someone must have taken the lock in between
# and garbage collected it. How annoying.
return 0;
}
+sub hkfail ($) { my ($msg) = @_; fail "housekeeping: $msg"; }
+
sub housekeeping () {
+ logm 'info', "housekeeping started";
foreach $lock (<[a-z]*\\.lock>) {
+ my $subdir = $lock; $subdir =~ s/\\.lock$//;
if (!lstat $lock) {
- $! == ENOENT or fail "housekeeping: $lock: stat: $!";
+ $! == ENOENT or hkfail "$lock: lstat: $!";
next;
}
if (-M _ <= $treeexpiredays) {
- logm 'debug', "housekeeping: $lock: not too old";
+ logm 'debug', "housekeeping: subdirs $subdir: touched recently";
next;
}
- my $subdir = $lock; $subdir =~ s/\\.lock$//;
- my $ok = 1;
- foreach my $suffix (qw(tmp git)) {
- my $dir = "${subdir}\\.$suffix";
- my $errs;
- remove_tree($dir, { safe=>1, error=>\$errs });
- $ok = 0 if @$errs;
- foreach my $err (@$errs) {
- logm 'warning', "problem deleting: $err[0]: $err[1]";
+ if (!lockfile \*LOCK, $lock, LOCK_EX|LOCK_NB) {
+ logm 'info', "housekeeping: subdirs $subdir: lock busy, skipping";
+ next;
+ }
+ logm 'info', "housekeeping: subdirs $subdir: cleaning";
+ eval {
+ foreach my $suffix (qw(tmp git)) {
+ my $dir = "${subdir}\\.$suffix";
+ my $tdir = "${subdir}\\.tmp";
+ if ($dir ne $tdir) {
+ if (!rename $dir,$tdir) {
+ next if $! == ENOENT;
+ die "$dir: cannot rename to $tdir: $!\n";
+ }
+ }
+ system qw(rm -rf --), $tdir;
+ if (stat $tdir) {
+ die "$dir: problem deleting file(s), rm exited $?\n";
+ } elsif ($! != ENOENT) {
+ die "$tdir: cannot stat after deletion: $!\n";
+ }
}
+ };
+ if (length $@) {
+ chomp $@;
+ logm 'warning', "housekeeping: $subdir: cleanup prevented: $@";
+ } else {
+ unlink $lock or hkfail "remove $lock: $!";
}
- if ($ok) {
-
+ }
+ open HS, ">", "Housekeeping.stamp" or hkfail "touch Housekeeping.stamp: $!";
+ close HS or hkfail "close Housekeeping.stamp: $!";
+ logm 'info', "housekeeping finished";
+}
sub housekeepingcheck ($$) {
my ($dofork, $force) = @_;
- open HLOCK, "+>", "Housekeeping.lock"
- or fail "open/create Housekeeping.lock: $!";
if (!$force) {
- if (flock HLOCK, LOCK_EX|LOCK_NB) {
+ if (!lockfile \*HLOCK, "Housekeeping.lock", LOCK_EX|LOCK_NB) {
logm 'debug', "housekeeping lock taken, not running";
close HLOCK;
return 0;
if ($force) {
logm 'info', "housekeeping forced";
} elsif (!lstat "Housekeeping.stamp") {
- $! == ENOENT or fail "stat housekeeping.stamp: $!";
- logm 'info', "housekeeping stamp missing, will run";
- } elsif (-M _ <= $housekeepingthreshdays) {
+ $! == ENOENT or fail "lstat Housekeeping.stamp: $!";
+ logm 'info', "housekeeping not done yet, will run";
+ } elsif (-M _ <= $housekeepingeverydays) {
logm 'debug', "housekeeping done recently";
close HLOCK;
return 0;
}
if ($dofork) {
my $child = fork;
- defined $child or fail "fork for housekeeping: $!";
+ defined $child or fail "fork: $!";
if (!$child) {
+ open STDERR, "|logger -p daemon.warning -t '$us(housekeeping)'"
+ or die "fork: logger $!";
housekeeping();
exit 0;
}
- return 1;
} else {
housekeeping();
- return 1;
}
+ close HLOCK;
+ return 1;
}
sub runcommand () {
- servinfo "servicing";
+ servinfo "serving";
+
+ chdir $gitd or fail "chdir $gitd: $!";
+
exec qw(git-upload-pack --strict --timeout=1000 .)
or fail "exec git-upload-pack: $!";
}
sub daemonservice () {
readcommand();
while (!clonefetch()) { }
+ housekeepingcheck(1,0);
runcommand();
}
-daemonservice();
+if ($housekeepingonly) {
+ housekeepingcheck(0, $housekeepingonly>=2);
+} else {
+ daemonservice();
+}
~ian / chiark-utils.git / blobdiff