Bug: loggelf in lib/errors.js is not overridable

[titanism]

Currently several parts of the codebase have this line:

const errors = require('../../lib/errors.js');

This requires this module: https://github.com/nodemailer/wildduck/blob/master/lib/errors.js

Specifically this code

wildduck/lib/errors.js

Lines 75 to 90 in 7daa0e3

	try {
	module.exports.gelf.handler.emit('gelf.log', message);
	} catch (err) {
	// might fail on non-JSONizable input
	try {
	console.error(err);
	console.error(util.inspect(message, false, 3));
	} catch (err) {
	//ignore
	}
	}
	};
	module.exports.notify = (...args) => {
	loggelf(...args);
	};

When errors.notifyConnection(this.this, err); is called throughout the codebase, it uses this default loggelf and outputs to console:

module.exports.gelf.handler = gelfconf.enabled
    ? new Gelf(gelfconf.options)
    : {
          emit: (channel, message) => console.error(util.inspect(message, false, 3))
      };

This uses wild-config and it is documented here

wildduck/docs/in-depth/operating-wildduck.md

Line 5 in 7daa0e3

WildDuck sends gelf-formatted log messages to a Graylog server. Set `log.gelf.enabled=true` in [config](https://github.com/nodemailer/wildduck/blob/2019fd9db6bce1c3167f08e363ab4225b8c8a296/config/default.toml#L59-L66) to use it. Also make sure that the same Gelf settings are set for _zonemta-wildduck_ and _haraka-plugin-wildduck_ in order to get consistent logs about messages throughout the system.

There's no way to disable this programmatically, as it has to be read from a config file:

wildduck/config/default.toml

Lines 59 to 66 in 2019fd9

	[log.gelf]
	enabled=false
	hostname=false # defaults to os.hostname()
	component="wildduck"
	[log.gelf.options]
	graylogPort=12201
	graylogHostname='127.0.0.1'
	connection='lan'

I suppose we can create a config/default.toml file with this override:

[log]
    [log.gelf]
        enabled=false
        hostname=false # defaults to os.hostname()
        component="wildduck"

However I feel like this should be configurable via code options, e.g. when passed logger option or via server.loggelf.

Curious your thoughts, right now this causes unwanted output in the console for those of us using WildDuck components programmatically.

[titanism]

Yes this is a bug, because even if logger is disabled, and if gelf is disabled via the example config above, it will still output to console due to this line:

wildduck/lib/errors.js

Line 23 in 7daa0e3

emit: (channel, message) => console.error(util.inspect(message, false, 3))