From 04875beb79a8b98f3079fb866beb5ede835772a5 Mon Sep 17 00:00:00 2001
From: Daniel Berteaud <daniel@firewall-services.com>
Date: Tue, 26 Mar 2019 09:31:08 +0100
Subject: [PATCH] Implement disabling compression, only save cursor every 30
 sec or when exiting

---
 systemd-journal-gelf | 77 ++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 53 insertions(+), 24 deletions(-)

diff --git a/systemd-journal-gelf b/systemd-journal-gelf
index 4afd910..f993b17 100644
--- a/systemd-journal-gelf
+++ b/systemd-journal-gelf
@@ -10,10 +10,50 @@ use Getopt::Long;
 use YAML::Tiny;
 use MIME::Base64;
 
+
+#### Global vars ####
+
 my $conf = {};
 my $cmd = {
   config => '/etc/systemd/journal-gelf.yml'
 };
+my $cursor = undef;
+my $last_save = 0;
+my $cursor_re = qr{^s=[a-z\d]+;i=[a-z\d]+;b=[a-z\d]+;m=[a-z\d]+;t=[a-z\d]+;x=[a-z\d]+$};
+
+#### End global vars
+
+
+#### Routines #####
+
+sub help {
+  print <<"_EOF"
+
+Usage: $0 --url=<URL> [--compress|--no-compress] [--user=production --password=secr3t] [--state=/path/to/file]
+
+  * --url is the http or https URL where you will push your gelf formated logs. This is mandatory
+  * --compress or --no-compress : will turn on or off gzip compression of logs. Default is on, but can be usefull to disable for debugging
+  * --username and --password may be used if URL is protected with a basic auth mecanism. Either both or none must be provided
+  * --state can be used to specify where to record the last correctly sent message, so we can start from here when
+    systemd-journal-gelf is restarted or if there's a network problem. Default value is /var/lib/systemd-journal-gelf/state
+
+_EOF
+}
+
+sub save_cursor {
+  if ($cursor and $cursor =~ m/$cursor_re/){
+    open CURSOR, ">", $conf->{state};
+    print CURSOR $cursor;
+    close CURSOR
+  }
+}
+
+sub handle_stop {
+  print "Saving current cursor to " . $conf->{state} . "\n";
+  save_cursor();
+}
+
+#### End Routines ####
 
 GetOptions (
   'c|config=s' => \$cmd->{config},
@@ -62,6 +102,10 @@ if (
 
 print "Starting the Systemd Journal GELF uploader daemon\n";
 
+# Catch SIGTERM and save the cursor !
+$SIG{TERM} = 'handle_stop';
+$SIG{INT}  = 'handle_stop';
+
 my $ua = LWP::UserAgent->new(
   env_proxy  => 1,
   keep_alive => 1
@@ -86,7 +130,7 @@ open CURSOR, "+<", $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 $cursor =~ m/$cursor_re/ ){
     print "Valid cursor found in " . $conf->{state} . ", will start back from here\n";
     $cursor_arg = " --after-cursor='" . $cursor . "'";
   } else {
@@ -149,12 +193,7 @@ while ( my $entry = <JOURNAL> ){
     }
     $resp = $ua->post(
       $conf->{url},
-      Content => Compress::Zlib::memGzip(
-        encode(
-          'utf-8',
-          to_json($gelf)
-        )
-      )
+      Content => ($conf->{compress}) ? Compress::Zlib::memGzip(encode('utf-8', to_json($gelf))) : encode('utf-8', to_json($gelf))
     );
     $retry = ($retry > 0) ? $retry * 2 : 1;
   } while (not $resp->is_success and $retry < 600);
@@ -162,9 +201,13 @@ while ( my $entry = <JOURNAL> ){
   # The message has been accepted, we can save the current cursor and
   # continue
   if ($resp->is_success){
-    open CURSOR, ">", $conf->{state};
-    print CURSOR $msg->{__CURSOR};
-    close CURSOR
+    $cursor = $msg->{__CURSOR};
+    # Save the current cursor to disk if
+    # it hasn't been done for the past 30 sec
+    if (time - $last_save > 30) {
+      $last_save = time;
+      save_cursor();
+    }
   } else {
     # We can't upload our current message for
     # too much time, no much left we can do, lets die and hope
@@ -172,17 +215,3 @@ while ( my $entry = <JOURNAL> ){
     die "Error sending data to GELF server\n";
   }
 }
-
-sub help {
-  print <<"_EOF"
-
-Usage: $0 --url=<URL> [--compress|--no-compress] [--user=production --password=secr3t] [--state=/path/to/file]
-
-  * --url is the http or https URL where you will push your gelf formated logs. This is mandatory
-  * --compress or --no-compress : will turn on or off gzip compression of logs. Default is on, but can be usefull to disable for debugging
-  * --username and --password may be used if URL is protected with a basic auth mecanism. Either both or none must be provided
-  * --state can be used to specify where to record the last correctly sent message, so we can start from here when
-    systemd-journal-gelf is restarted or if there's a network problem. Default value is /var/lib/systemd-journal-gelf/state
-
-_EOF
-}