Mojolicious logging with hypnotoad and systemd

[daleif]

Does anyone have good experience with mojo logging when running the applications via hypnotoad and systemd.

As far as I know the logging to stderr etc should be pucked up by systemd and is viewable in the journal.

As far as I can tell I can get my app to log something from the setup method, everything else just disappears.

Running hypnotoad manual in the foreground logs just fine just as we get with morbo.

I'm assuming that it is the logs from the workers that are lost?

Any ideas?

[kraih]

Just use prefork instead of Hypnotoad with systemd.

[jhthorsen]

@daleif: I guess it could be mentioned somewhere, but since Hypnotoad detaches itself from the terminal then there isn't really any sensible place to send STDERR / STDOUT. Maybe create a documentation PR? :)

I'm also curious (as mentioned earlier) how "systemctl reload" would work with multiple multiple processes using reuse=1.

[daleif]

I'm wondering, what happens if one explicitly instruct the app to use a specific file for logging. Will the workers under hypnotoad then be able to log to it?

[daleif]

Using a specific file to log to seems to be working as well, at least I'm getting logs in from the worker processes. Just remember the user specified under systemd config needs to have write access to the folder with the log file.

Just need a proper place for the logs which can also be configured with logrotate or similar.

[guest20]

I think you just want to run hypnotoad -f under systemd, that way it doesn't close the handles and journald can slurp up the logs from STDOUT/ERR

[daleif]

@guest20 to be honest, I kinda like having the logs of each app in a separate log file

[daleif]

In the end I've opted to to have startup set a specific log file when in production

  if ( $self->mode eq 'production' && $config->{'log_file_production'} ) {
      $self->log( Mojo::Log->new( path => $config->{'log_file_production'},
      				  level => 'info') );
    }

seems to cover all my needs.

One additional question. When combining this with log_rotate, does the hypnotoad process need to be reloaded? (I noticed that reloading systemd services was one of the things that log_rotate could do).

[s1037989]

I know this wasn't your question, but you can use deployment-specific configuration files, e.g. app.development.conf and app.production.conf. Each would specify the log file to use, and even whether or not to use a log file or just log to stdout.

sub startup ($self) {
  my $cfg = $self->plugin('Config');
  $self->log->path($cfg->{log_file}) if $cfg->{log_file};
}

[daleif]

Interesting. Did not know that.

Am I reading it correctly that $moniker.$mode.conf will extend/overwrite what is in $moniker.conf

That would be useful. Thank you for the hint.

[jhthorsen]

If you want, you could try out https://metacpan.org/pod/Mojo::Server::DaemonControl