systemd syslog-ng service fails to activate

[basvandijk]

I'm upgrading my systems from NixOS 16.03 to 16.09 and I'm trying to get syslog-ng working again. It's currently configured as:

{ syslog-ng.enable = true; }

The issue is that systemd is not noticing that syslog-ng has started:

Nov 04 12:47:08 mymachine systemd[1]: syslog-ng.service: Start operation timed out. Terminating.
Nov 04 12:47:08 mymachine systemd[1]: Failed to start syslog-ng daemon.
Nov 04 12:47:08 mymachine systemd[1]: syslog-ng.service: Unit entered failed state.
Nov 04 12:47:08 mymachine systemd[1]: syslog-ng.service: Failed with result 'timeout'.
Nov 04 12:47:08 mymachine systemd[1]: syslog-ng.service: Service hold-off time over, scheduling restart.

I do see that syslog-ng is running:

# ps -AH a | grep syslog
/nix/store/kag473gb3w8zaqw09qkgsjg2qn4ra5zc-syslog-ng-3.6.2/sbin/syslog-ng --foreground --module-path=/nix/store/kag473gb3w8zaqw09qkgsjg2qn4ra5zc-syslog-ng-3.6.2/lib/syslog-ng --cfgfile=/nix/store/8f9npiv1fyc487haxj0ff957ag7zqzld-syslog-ng.conf --control=/run/syslog-ng/syslog-ng.ctl --persist-file=/var/syslog-ng/syslog-ng.persist --pidfile=/run/syslog-ng/syslog-ng.pid

Note that the systemd syslog-ng service is configured with Type = "notify"; This means that syslog-ng should notify systemd when it has started up. My current hypotheses is that with the systemd upgrade to 231 something in the notification protocol has changed causing the syslog-ng notification to fail.

[danbst]

It has strange config:

      wantedBy = [ "multi-user.target" ];
      after = [ "multi-user.target" ]; # makes sure hostname etc is set

how could this work ?

@basvandijk could you test this? syslog-ng at least starts for me

diff --git a/nixos/modules/services/logging/syslog-ng.nix b/nixos/modules/services/logging/syslog-ng.nix
index 21be286..fd6ab7d 100644
--- a/nixos/modules/services/logging/syslog-ng.nix
+++ b/nixos/modules/services/logging/syslog-ng.nix
@@ -82,9 +82,9 @@ in {
       description = "syslog-ng daemon";
       preStart = "mkdir -p /{var,run}/syslog-ng";
       wantedBy = [ "multi-user.target" ];
-      after = [ "multi-user.target" ]; # makes sure hostname etc is set
+      after = [ "network.target" ]; # makes sure hostname etc is set
       serviceConfig = {
-        Type = "notify";
+        Type = "simple";
         StandardOutput = "null";
         Restart = "on-failure";
         ExecStart = "${cfg.package}/sbin/syslog-ng ${concatStringsSep " " syslogngOptions}";

[basvandijk]

thanks @danbst, with those changes syslog-ng starts up correctly.

[fpletz]

how could this work ?

wantedBy means that the syslog-ng unit will be activated (started) if multi-user.target gets activated. By itself this relation defines no order. That's why you can add after and before relations as you wish.

As I've mention in #20211, the root problem is that our current version of syslog-ng can't be built with our current version of systemd and thus the sd-notify feature is not present.

[basvandijk]

Hi @fpletz, I did some work on the syslog-ng upgrade. I've managed to get syslog-ng-3.9.1 to build with LumiGuide@ee0826e. I will now test this a bit.