#! /usr/bin/perl

=head1 NAME

phpfpm-multi - Munin multigraph plugin to monitor PHP FPM pools

=head1 APPLICABLE SYSTEMS

PHP FPM installations, tested with PHP 5.6, 7.0 and 7.2 FPM.

Requires the JSON perl module and the C<cgi-fcgi> tool. On Debian systems
install them using C<apt-get install libjson-perl libfcgi-bin> (older systems
don't have a C<libfcgi-bin> package, install the C<libfcgi0ldbl> package
instead).

=head1 CONFIGURATION

The plugin needs to be able to read the different pool configuration
files and needs access to the sockets. If root is the only user which
has access to these resources, the following needs to be configured:

    [phpfpm-multi]
    user root

The path to the socket as well as the status URL will be fetched read
from the configuration file.

In addition, the following variables can be defined:

=over

=item C<env.pooldir> (default: automatically discovered)

Directory containing the pool configuration files.

=item C<env.hide_pools> (default: empty)

Comma-separated list of pools for which no statistics should be
gathered.

=back

=head1 AUTHOR

Oliver Hitz <oliver@net-track.ch>

=head1 LICENSE

GPL

=cut

use strict;
use JSON;
use File::Spec;
use Munin::Plugin;

my $cfg_pooldir;

if ($ENV{pooldir}) {
  $cfg_pooldir = $ENV{pooldir};
} else {
  # Try to autodetect pool directory
  my $php_version = `php -v`;
  if ($php_version =~ /^PHP (\d+\.\d+)/) {
    $cfg_pooldir = "/etc/php/$1/fpm/pool.d/";
    # Debian 8 has the pool files of PHP 5.6 in /etc/php5/fpm/pool.d/,
    # so if the directory doesn't exist, fall-back to that one.
    if (! -d $cfg_pooldir && $php_version =~ /^PHP 5\./) {
      $cfg_pooldir = "/etc/php5/fpm/pool.d/";
    }
  } else {
    # Fall-back to default
    $cfg_pooldir = "/etc/php/7.0/fpm/pool.d/";
  }
}

my @cfg_hide_pools;
if ($ENV{hide_pools}) {
  @cfg_hide_pools = split /,/, $ENV{hide_pools};
}

# autoconf
if ($ARGV[0] eq "autoconf") {
  if (`which cgi-fcgi`) {
    print "yes\n";
  } else {
    print "no (cgi-fcgi not found)\n";
  }
  exit 0;
}

# Get the list of pools.
my @pools;

if (opendir my $dh, $cfg_pooldir) {
  while (my $entry = readdir $dh) {
    if ($entry !~ /\.conf$/) {
      next;
    }
    
    my $pool = {
      file => File::Spec->catfile($cfg_pooldir, $entry)
    };

    my $poolconf;
    if (!open($poolconf, $pool->{file})) {
      warning("Unable to pool configuration open %s.",
              $pool->{file});
      next;
    }

    while (my $line = <$poolconf>) {
      # Erase comments.
      $line =~ s/;.*$//;

      if ($line =~ /^\[([^\]]*)\]/) {
        $pool->{pool} = $1;
      } elsif ($line =~ /^listen\s*=\s*(\S+)$/) {
        $pool->{socket} = $1;
      } elsif ($line =~ /^pm.status_path\s*=\s*(\S+)$/) {
        $pool->{statuspath} = $1;
      }
    }

    close($poolconf);

    # Check if entries are valid.
    if (!$pool->{pool}) {
      warning("Skipping pool %s: no pool name.",
              $pool->{file});
      next;
    }
    if (!$pool->{socket}) {
      warning("Skipping pool %s: no socket.",
              $pool->{file});
      next;
    }
    if (!$pool->{statuspath}) {
      warning("Skipping pool %s: no pm.status_path configured.",
              $pool->{file});
      next;
    }

    # Replace $pool in socket and pm.status_path
    $pool->{socket} =~ s/\$pool/$pool->{pool}/g;
    $pool->{statuspath} =~ s/\$pool/$pool->{pool}/g;

    # Connect to pool.
    $ENV{'SCRIPT_NAME'} = $pool->{statuspath};
    $ENV{'SCRIPT_FILENAME'} = $pool->{statuspath};
    $ENV{'QUERY_STRING'} = "json";
    $ENV{'REQUEST_METHOD'} = "GET";
    my $sh = sprintf("cgi-fcgi -bind -connect %s", $pool->{socket});
    my $out_str = `$sh`;
    if ($? != 0) {
      printf "cgi-fcgi returned %d\n", $? >> 8;
    } else {
      # Strip header lines:
      my @out_lines = split /\n/, $out_str;
      while (@out_lines && $out_lines[0] !~ /^\r$/) {
        shift @out_lines;
      }
      shift @out_lines;
      
      $pool->{values} = decode_json(join "\n", @out_lines);
    }
    
    push @pools, $pool;
  }
  closedir($dh);
}

sort { $a->{pool} cmp $b->{pool}; } @pools;

if ($ARGV[0] eq "config") {
  print <<"EOF";
multigraph phpfpm_connections
graph_title PHP-FPM Accepted Connections
graph_args --base 1024 -l 0
graph_vlabel Connections
graph_category PHP
graph_info Shows the number of accepted connections to the PHP-FPM pool.
EOF
  foreach my $pool (@pools) {
    my $poolname = $pool->{pool};
    if (grep { $_ eq $poolname } @cfg_hide_pools) {
      next;
    }
    print <<"EOF";
${poolname}_connections.label $poolname
${poolname}_connections.type DERIVE
${poolname}_connections.draw AREASTACK
${poolname}_connections.min 0
EOF
  }

  print <<"EOF";

multigraph phpfpm_active_processes
graph_title PHP-FPM Active Processes
graph_args --base 1000 -l 0
graph_vlabel Processes
graph_category PHP
graph_info Shows the number of PHP-FPM processes.
EOF
  foreach my $pool (@pools) {
    my $poolname = $pool->{pool};
    if (grep { $_ eq $poolname } @cfg_hide_pools) {
      next;
    }
    print <<"EOF";
${poolname}_active_processes.label $poolname
${poolname}_active_processes.type GAUGE
${poolname}_active_processes.draw AREASTACK
${poolname}_active_processes.min 0
EOF
  }

  print <<"EOF";

multigraph phpfpm_max_active_processes
graph_title PHP-FPM Max Active Processes
graph_args --base 1000 -l 0
graph_vlabel Max Processes
graph_category PHP
graph_info Shows the number of max PHP-FPM processes reached.
EOF
  foreach my $pool (@pools) {
    my $poolname = $pool->{pool};
    if (grep { $_ eq $poolname } @cfg_hide_pools) {
      next;
    }
    print <<"EOF";
${poolname}_max_active_processes.label $poolname
${poolname}_max_active_processes.type GAUGE
${poolname}_max_active_processes.draw AREASTACK
${poolname}_max_active_processes.min 0
EOF
  }

  exit 0;
}

my $out = "";

print "multigraph phpfpm_connections\n";
foreach my $pool (@pools) {
  my $poolname = $pool->{pool};
  if (grep { $_ eq $poolname } @cfg_hide_pools) {
    next;
  }
  printf("%s_connections.value %d\n",
         $pool->{pool},
         $pool->{values}->{"accepted conn"});
}

print "multigraph phpfpm_active_processes\n";
foreach my $pool (@pools) {
  my $poolname = $pool->{pool};
  if (grep { $_ eq $poolname } @cfg_hide_pools) {
    next;
  }
  printf("%s_active_processes.value %d\n",
         $pool->{pool},
         $pool->{values}->{"active processes"});
}

print "multigraph phpfpm_max_active_processes\n";
foreach my $pool (@pools) {
  my $poolname = $pool->{pool};
  if (grep { $_ eq $poolname } @cfg_hide_pools) {
    next;
  }
  printf("%s_max_active_processes.value %d\n",
         $pool->{pool},
         $pool->{values}->{"max active processes"});
}

exit 0;

sub warning
{
  my $msg = shift;
  my (@args) = @_;  
  printf STDERR "WARNING: %s\n", sprintf($msg, @args);
}