-#!/usr/bin/perl
+#!/usr/bin/perl -w
#
# git caching proxy
-#
+
# usage: run it on some port, and then clone or fetch
-# git://<realhost>:<realport>/<real-git-url>
+# "git://<realhost>:<realport>/<real-git-url>[ <options>]"
# where <real-git-url> is http://<host>/... or git://<host>/...
+# and <options> is zero or more (whitespace-separated) of
+# [<some-option>] will be ignored if not recognised
+# {<some-option>} error if not recognised
+# options currently known:
+# fetch=must fail if the fetch/clone from upstream fails
+# fetch=no just use what is in the cache
+# fetch=try use what is in the cache if the fetch/clone fails
+# timeout=<seconds> length of time to allow for fetch/clone
+
+# 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
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, consult the Free Software Foundation's
+# website at www.fsf.org, or the GNU Project website at www.gnu.org.
+#
+# (Some code taken from userv-utils's git-daemon.in and git-service.in
+# which were written by Tony Finch <dot@dotat.at> and subsequently
+# heavily modified by Ian Jackson <ijackson@chiark.greenend.org.uk>
+# and were released under CC0 1.0. The whole program is now GPLv3+.)
use strict;
use warnings;
use POSIX;
use Socket;
use Sys::Syslog;
+use Fcntl qw(:flock SEEK_SET);
+use File::Path qw(remove_tree);
our $us = 'git-cache-proxy';
+
+#---------- error handling and logging ----------
+
+# This is a bit fiddly, because we want to catch errors sent to stderr
+# and dump them to syslog if we can, but only if we are running as an
+# inetd service.
+
our $log; # filehandle (ref), or "1" meaning syslog
-our $fetchtimeout = 1800;
-our $maxfetchtimeout = 3600;
sub ntoa {
my $sockaddr = shift;
return ("[$addr]:$port",$addr,$port);
}
-our ($client,$client_addr,$client_port) = ntoa getpeername STDIN;
-our ($server,$server_addr,$server_port) = ntoa getsockname STDIN;
+our ($client) = ntoa getpeername STDIN;
+our ($server) = ntoa getsockname STDIN;
sub ensurelog () {
return if $log;
$log = 1;
}
-sub log ($) {
+sub logm ($$) {
my ($pri, $msg) = @_;
+ if ($client eq '(local)') {
+ print STDERR "$us: $pri: $msg\n" or die $!;
+ exit 1;
+ }
ensurelog();
my $mainmsg = sprintf "%s-%s: %s", $server, $client, $msg;
if (ref $log) {
}
}
+if ($client ne '(local)') {
+ open STDERR, ">/dev/null" or exit 255;
+ open TEMPERR, "+>", undef or exit 255;
+ open STDERR, ">&TEMPERR" or exit 255;
+}
+
+END {
+ if ($client ne '(local)') {
+ if ($?) { logm 'crit', "crashing ($?)"; }
+ seek TEMPERR, 0, SEEK_SET;
+ while (<TEMPERR>) {
+ chomp;
+ logm 'crit', $_;
+ }
+ }
+ exit $?;
+}
+
sub fail ($) {
my ($msg) = @_;
- log 'error', $msg;
- exit 1;
+ logm 'err', $msg;
+ exit 0;
}
sub gitfail ($) {
my ($msg) = @_;
- log 'warning', $msg;
+ close LOCK;
+ alarm 60;
+ logm 'notice', $msg;
my $gitmsg = "ERR $us: $msg";
$gitmsg = substr($gitmsg,0,65535); # just in case
printf "%04x%s", length($gitmsg)+4, $gitmsg;
flush STDOUT;
- exit 1;
+ exit 0;
}
+#---------- argument parsing ----------
+
+our $housekeepingthreshdays = 1;
+our $treeexpiredays = 21;
+our $fetchtimeout = 1800;
+our $maxfetchtimeout = 3600;
our $cachedir = '/var/cache/git-cache-proxy';
for (;;) {
!@ARGV or fail "bad usage: no non-option arguments permitted";
-chdir $cachedir or fail "chdir $cachedir: $!";
+#---------- main program ----------
-our ($service,$specpath,$spechost);
+chdir $cachedir or fail "chdir $cachedir: $!";
-$SIG{ALRM} = sub { fail "timeout" };
-alarm 30;
+our ($service,$specpath,$spechost,$subdir);
+our ($tmpd,$gitd,$lock);
+our ($fetch,$url);
sub xread {
my $length = shift;
my $buffer = "";
while ($length > length $buffer) {
my $ret = sysread STDIN, $buffer, $length, length $buffer;
- fail "Expected $length bytes, got ".length $buffer
+ fail "expected $length bytes, got ".length $buffer
if defined $ret and $ret == 0;
fail "read: $!" if not defined $ret and $! != EINTR and $! != EAGAIN;
}
return $buffer;
}
-my $hex_len = xread 4;
-fail "Bad hex in packet length" unless $hex_len =~ m|^[0-9a-fA-F]{4}$|;
-my $line = xread -4 + hex $hex_len;
-unless (($service,$specpath,$spechost) = $line =~
- m|^(git-[a-z-]+) /*([!-~]+)\0host=([!-~]+)\0$|) {
- $line =~ s|[^ -~]+| |g;
- fail "Could not parse \"$line\""
-}
-alarm 0;
-
-$service eq 'git-upload-pack'
- or gitfail "unknown/unsupported service `$service'";
-
-my $fetch = 2; # 0:don't; 1:try; 2:force
-my $url = $specpath;
-
-while ($url =~ s#^(\[)([^][{}])+\]## ||
- $url =~ s#^(\{)([^][{}])+\}##) {
- $_ = $2;
- my $must = $1 eq '{';
- if (m/^relaxed$/) {
- $fetch = 1;
- } elsif (m/^nofetch$/) {
- $fetch = 0;
- } elsif (m/^timeout=(\d+)$/) {
- $fetchtimeout = $1 <= $maxfetchtimeout ? $1 : $maxfetchtimeout;
- } elsif ($must) {
- gitfail "unknown/unsupported option `$_'";
- }
+sub servinfo ($) {
+ my ($msg) = @_;
+ logm 'info', "service `$specpath': $msg";
}
-$url =~ m{^(?:https?|git)://[-.0-9a-z]+/}
- or gitfail "unknown/unsupported url scheme or format `$url'";
-
-our $subdir = $url;
-$subdir =~ s|\\|\\\\|g;
-$subdir =~ s|,|\\,|g;
-$subdir =~ s|/|,|g;
-
-log 'info', "$specpath locking";
-
-my $tmpd= "$subdir\\.tmp";
-my $gitd= "$subdir\\.git";
-my $lock = "$subdir\\.lock";
+sub readcommand () {
+ $SIG{ALRM} = sub { fail "timeout" };
+ alarm 30;
+
+ my $hex_len = xread 4;
+ fail "Bad hex in packet length" unless $hex_len =~ m|^[0-9a-fA-F]{4}$|;
+ my $line = xread -4 + hex $hex_len;
+ unless (($service,$specpath,$spechost) = $line =~
+ m|^(git-[a-z-]+) /*([!-~ ]+)\0host=([!-~]+)\0$|) {
+ $line =~ s|[^ -~]+| |g;
+ gitfail "unknown/unsupported instruction `$line'"
+ }
-open LOCK, "+>", $lock or fail "open/create $lock: $!";
-flock LOCK, LOCK_EX or fail "lock $lock: $!";
+ alarm 0;
+
+ $service eq 'git-upload-pack'
+ or gitfail "unknown/unsupported service `$service'";
+
+ $fetch = 2; # 0:don't; 1:try; 2:force
+ $url = $specpath;
+
+ while ($url =~ s#\s+(\[)([^][{}]+)\]$## ||
+ $url =~ s#\s+(\{)([^][{}]+)\}$##) {
+ $_ = $2;
+ my $must = $1 eq '{';
+ if (m/^fetch=try$/) {
+ $fetch = 1;
+ } elsif (m/^fetch=no$/) {
+ $fetch = 0;
+ } elsif (m/^fetch=must$/) {
+ $fetch = 2; # the default
+ } elsif (m/^timeout=(\d+)$/) {
+ $fetchtimeout = $1 <= $maxfetchtimeout ? $1 : $maxfetchtimeout;
+ } elsif ($must) {
+ gitfail "unknown/unsupported option `$_'";
+ }
+ }
-$exists = stat $gitd;
-$exists or $!==ENOENT or FAIL "stat $gitd: $!";
+ $url =~ m{^(?:https?|git)://[-.0-9a-z]+/}
+ or gitfail "unknown/unsupported url scheme or format `$url'";
-if ($fetch) {
+ $subdir = $url;
+ $subdir =~ s|\\|\\\\|g;
+ $subdir =~ s|,|\\,|g;
+ $subdir =~ s|/|,|g;
- our @cmd;
+ $tmpd= "$subdir\\.tmp";
+ $gitd= "$subdir\\.git";
+ $lock = "$subdir\\.lock";
- if (!$exists) {
- system qw(rm -rf --), $tmpd;
- @cmd = qw(git clone -q --mirror), $url;
- log 'info', "$specpath cloning";
- } else {
- @cmd = qw(git remote update --prune), $url;
- log 'info', "$specpath fetching";
- }
-
- my $child = open P, "-|";
- defined $child or fail "fork: $!";
- if (!$child) {
- if ($exists) {
- chdir $gitd or fail "chdir $gitd: $!";
- }
- setpgrp or fail "setpgrp: $!";
- open STDERR, ">&STDOUT" or fail "redirect stderr: $!";
- exec @cmd or fail "exec $cmd[0]: $!";
- }
+ servinfo "locking";
+}
- local $SIG{ALARM} = sub {
- kill 9, -$child;
-
- } or log 'crit',
- };
+sub clonefetch () {
+ open LOCK, "+>", $lock or fail "open/create $lock: $!";
+ flock LOCK, LOCK_EX or fail "lock exclusive $lock: $!";
- alarm($fetchtimeout);
-
+ my $exists = stat $gitd;
+ $exists or $!==ENOENT or fail "stat $gitd: $!";
-printf STDERR "%s [$$] %s %s\n",
- strftime("%Y-%m-%d %H:%M:%S %Z", localtime), $server, $client;
+ our $fetchfail = '';
+ if ($fetch) {
+ our @cmd;
+ if (!$exists) {
+ system qw(rm -rf --), $tmpd;
+ @cmd = (qw(git clone -q --mirror), $url, $tmpd);
+ servinfo "cloning";
+ } else {
+ @cmd = (qw(git remote update --prune));
+ servinfo "fetching";
+ }
+ my $cmd = "@cmd[0..1]";
+
+ my $child = open FETCHERR, "-|";
+ defined $child or fail "fork: $!";
+ if (!$child) {
+ if ($exists) {
+ chdir $gitd or fail "chdir $gitd: $!";
+ }
+ setpgrp or fail "setpgrp: $!";
+ open STDERR, ">&STDOUT" or fail "redirect stderr: $!";
+ exec @cmd or fail "exec $cmd[0]: $!";
+ }
+ my $fetcherr = '';
+ my $timedout = 0;
+ {
+ local $SIG{ALRM} = sub {
+ servinfo "fetch/clone timeout";
+ $timedout=1; kill 9, -$child;
+ };
+ alarm($fetchtimeout);
+ $!=0; { local $/=undef; $fetcherr = <FETCHERR>; }
+ !FETCHERR->error or fail "read pipe from fetch/clone: $!";
+ alarm(10);
+ }
-$service eq '
+ kill -9, $child or fail "kill fetch/clone: $!";
+ $!=0; $?=0; if (!close FETCHERR) {
+ fail "reap fetch/clone: $!" if $!;
+ my $fetchfail =
+ !($? & 255) ? "$cmd died with error exit code ".($? >> 8) :
+ $? != 9 ? "$cmd died due to fatal signa, status $?" :
+ $timedout ? "$cmd timed out (${fetchtimeout}s)" :
+ "$cmd died due to unexpected SIGKILL";
+ if (length $fetcherr) {
+ $fetchfail .= "\n$fetcherr";
+ $fetchfail =~ s/\n$//;
+ $fetchfail =~ s{\n}{ // }g;
+ }
+ if ($fetch >= 2) {
+ gitfail $fetchfail;
+ } else {
+ servinfo "fetch/clone failed: $fetchfail";
+ }
+ }
-@@READ_URLMAP@@
+ if (!$exists) {
+ rename $tmpd, $gitd or fail "rename fresh $tmpd to $gitd: $!";
+ $exists = 1;
+ }
+ } else {
+ $fetchfail = 'not attempted';
+ }
-fail "No global mapping for $uri" unless defined $serve_user;
+ if (!$exists) {
+ gitfail "no cached data, and not cloned: $fetchfail";
+ }
-my ($hn,$ha,$at,$naddrs,@addrs) = gethostbyname $spechost;
-fail "hostname/address mismatch ($spechost $server_addr)" unless grep {
- $server_addr eq inet_ntoa $_
- } @addrs;
+ 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
-our @opts;
+ if (chdir $gitd) {
+ return 1;
+ }
+ $!==ENOENT or fail "chdir $gitd: $!";
-push @opts, "-D$_=${$::{$_}}"
- for qw(service specpath spechost
- client client_addr client_port
- server server_addr server_port);
+ # Well, err, someone must have taken the lock in between
+ # and garbage collected it. How annoying.
+ return 0;
+}
-fail "no user $serve_user" unless getpwnam($serve_user);
+sub housekeeping () {
+ foreach $lock (<[a-z]*\\.lock>) {
+ if (!lstat $lock) {
+ $! == ENOENT or fail "housekeeping: $lock: stat: $!";
+ next;
+ }
+ if (-M _ <= $treeexpiredays) {
+ logm 'debug', "housekeeping: $lock: not too old";
+ 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 ($ok) {
+
+
+sub housekeepingcheck ($$) {
+ my ($dofork, $force) = @_;
+ open HLOCK, "+>", "Housekeeping.lock"
+ or fail "open/create Housekeeping.lock: $!";
+ if (!$force) {
+ if (flock HLOCK, 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 _ <= $housekeepingthreshdays) {
+ logm 'debug', "housekeeping done recently";
+ close HLOCK;
+ return 0;
+ }
+ if ($dofork) {
+ my $child = fork;
+ defined $child or fail "fork for housekeeping: $!";
+ if (!$child) {
+ housekeeping();
+ exit 0;
+ }
+ return 1;
+ } else {
+ housekeeping();
+ return 1;
+ }
+}
-syslog 'notice', "$client $service $uri $serve_user";
+sub runcommand () {
+ servinfo "servicing";
+ exec qw(git-upload-pack --strict --timeout=1000 .)
+ or fail "exec git-upload-pack: $!";
+}
-my @cmd = ('userv', '-t300', @opts, $serve_user, $service);
-no warnings; # suppress errors to stderr
-exec @cmd or fail "exec userv: $!";
+sub daemonservice () {
+ readcommand();
+ while (!clonefetch()) { }
+ runcommand();
+}
-# end
+daemonservice();
~ian / chiark-utils.git / blobdiff