Lots of little improvements

systemd-journal-gelf

@@ -5,38 +5,55 @@ use strict;
 use JSON;
 use LWP::UserAgent;
 use Encode qw(encode);
-use Data::Dumper;
 use Compress::Zlib;
 use Getopt::Long;
 use YAML::Tiny;
 
-my $config = '/etc/systemd/journal-gelf.yml';
 my $conf = {};
+my $cmd = {
+  config => '/etc/systemd/journal-gelf.yml'
+};
 
-if (-e $config) { 
-  print "Reading config file $config\n";
-  my $yaml = YAML::Tiny->read( $config ) or die "Config file $config is invalid\n";
-  if (not $yaml->[0]) {
-    die "Config file $config is invalid\n"
+GetOptions (
+  'c|config=s' => \$cmd->{config},
+  'state=s'    => \$cmd->{state},
+  'compress!'  => \$cmd->{compress},
+  'url=s'      => \$cmd->{url},
+  'username=s' => \$cmd->{username},
+  'password=s' => \$cmd->{password}
+);
+
+# Open config file
+if (-e $cmd->{config}) {
+  print "Reading config file " . $cmd->{config} . "\n";
+  my $yaml = YAML::Tiny->read( $cmd->{config} )
+    or die "Config file " . $cmd->{config} . " is invalid\n";
+
+  if ( not $yaml->[0] ) {
+    die "Config file " . $cmd->{config} . " is invalid\n";
   }
+
+  # File could be parsed, lets load
+  # settings in $conf
   $conf = $yaml->[0];
+} else {
+  print "Config file " . $cmd->{config} . " does not exist, ignoring it\n";
 }
 
-GetOptions (
-  'state=s'    => \$conf->{state},
-  'compress!'  => \$conf->{compress},
-  'url=s'      => \$conf->{url},
-  'username=s' => \$conf->{username},
-  'password=s' => \$conf->{password}
-);
+# Command line override config file
+foreach ( keys %{ $cmd } ){
+  $conf->{$_} = $cmd->{$_} if ( $cmd->{$_} );
+}
 
+# Set some defaults is missing
 $conf->{state}    //= '/var/lib/systemd-journal-gelf/state';
 $conf->{compress} //= 1;
 
+# Now check config makes sens
 if (
      not $conf->{url} or
-     ($conf->{username} and not $conf->{password}) or
-     (not $conf->{username} and $conf->{password})
+     ( $conf->{username} and not $conf->{password} ) or
+     ( not $conf->{username} and $conf->{password} )
   ){
   help();
   die;
@@ -45,9 +62,10 @@ if (
 print "Starting the Systemd Journal GELF uploader daemon\n";
 
 my $ua = LWP::UserAgent->new(
-  # env_proxy => 1,
+  env_proxy  => 1,
   keep_alive => 1
 );
+
 $ua->default_header( 'Content-Type' => 'application/json' );
 if ( $conf->{compress} ){
   $ua->default_header( 'Accept-Encoding' => HTTP::Message::decodable );
@@ -57,10 +75,10 @@ if ( $conf->{compress} ){
 # Check if the state file exists and contains a valid cursor
 my $cursor_arg = '';
 open CURSOR, "+<", $conf->{state};
-if (-e $conf->{state}){
+if ( -e $conf->{state} ){
   my $cursor = <CURSOR>;
   close CURSOR;
-  if ($cursor and $cursor =~ m/^s=[a-z\d]+;i=[a-z\d]+;b=[a-z\d]+;m=[a-z\d]+;t=[a-z\d]+;x=[a-z\d]+$/){
+  if ( $cursor and $cursor =~ m/^s=[a-z\d]+;i=[a-z\d]+;b=[a-z\d]+;m=[a-z\d]+;t=[a-z\d]+;x=[a-z\d]+$/ ){
     print "Valid cursor found in " . $conf->{state} . ", will start back from here\n";
     $cursor_arg = " --after-cursor='" . $cursor . "'";
   } else {
@@ -70,28 +88,41 @@ if (-e $conf->{state}){
 }
 
 open JOURNAL, "/usr/bin/journalctl -f -o json$cursor_arg |";
-while (my $entry = <JOURNAL>){
-  my $msg = from_json($entry);
+while ( my $entry = <JOURNAL> ){
+  my $msg = from_json( $entry );
+
+  if ( not $msg ) {
+    # Oups, something is obviously wrong here
+    # journalctl didn't sent us valid JSON ?
+    print "Error parsing message ($msg) \n";
+    next;
+  }
+
+  # Build a basic GELF message
   my $gelf = {
     version        => 1.1,
     short_message  => $msg->{MESSAGE},
     host           => $msg->{_HOSTNAME},
-    timestamp      => int ($msg->{__REALTIME_TIMESTAMP} / (1000 * 1000)),
+    timestamp      => int ( $msg->{__REALTIME_TIMESTAMP} / ( 1000 * 1000 ) ),
     level          => $msg->{PRIORITY}
   };
+
   # Now lets look at the message. If it starts with gelf: we can split it and have further
   # fields to send. I use this to handle httpd or nginx logs for example
-  if ($msg->{MESSAGE} =~ m/^gelf:([a-zA-Z\d]+=([^\|])\|?)+/){
+  if ( $msg->{MESSAGE} =~ m/^gelf:([a-zA-Z\d]+=([^\|])\|?)+/ ){
     $msg->{MESSAGE} =~ s/^gelf://;
-    foreach (split /\|/, $msg->{MESSAGE}){
-      my ($key,$val) = split /=/, $_;
+    foreach ( split /\|/, $msg->{MESSAGE} ){
+      my ( $key, $val ) = split /=/, $_;
       $gelf->{'_' . lc $key} = $val;
     }
   }
-  foreach (grep !/^MESSAGE|_HOSTNAME|__REALTIME_TIMESTAMP|PRIORITY$/,  keys %$msg){
-    my $key = lc (($_ =~ m/^_/) ? $_ : '_' . $_);
-    $gelf->{$key} = $msg->{$_};
+
+  # Add the other attributes to the gelf message, except thos already treated
+  foreach ( grep !/^MESSAGE|_HOSTNAME|__REALTIME_TIMESTAMP|PRIORITY$/,  keys %$msg ){
+    $gelf->{$_} = $msg->{$_};
   }
+
+  # Now, we'll try to POST this message
   my $retry = 0;
   my $resp;
   do {
@@ -100,14 +131,28 @@ while (my $entry = <JOURNAL>){
         $resp->code . " (" . $resp->message . "). Tring again in $retry seconds\n";
       sleep $retry;
     }
-    $resp = $ua->post($conf->{url}, Content => Compress::Zlib::memGzip(encode('utf-8', to_json($gelf))));
+    $resp = $ua->post(
+      $conf->{url},
+      Content => Compress::Zlib::memGzip(
+        encode(
+          'utf-8',
+          to_json($gelf)
+        )
+      )
+    );
     $retry = ($retry > 0) ? $retry * 2 : 1;
-  } while ($resp->code != 202 and $retry < 600);
-  if ($resp->code == 202){
+  } while (not $resp->is_success and $retry < 600);
+
+  # The message has been accepted, we can save the current cursor and
+  # continue
+  if ($resp->is_success){
     open CURSOR, ">", $conf->{state};
     print CURSOR $msg->{__CURSOR};
     close CURSOR
   } else {
+    # We can't upload our current message for
+    # too much time, no much left we can do, lets die and hope
+    # our service manager will restart us :-)
     die "Error sending data to GELF server\n";
   }
 }