fluent-logger for Node.js
fluent-logger implementation for Node.js inspired by fluent-logger-python.
Install
$ npm install fluent-logger
Prerequistes
Fluent daemon should listen on TCP port.
Simple configuration is following:
<source>
@type forward
port 24224
</source>
<match **.*>
@type stdout
</match>
Usage
Send an event record to Fluentd
Singleton style
var logger = require('fluent-logger')
// The 2nd argument can be omitted. Here is a default value for options.
logger.configure('tag_prefix', {
host: 'localhost',
port: 24224,
timeout: 3.0,
reconnectInterval: 600000 // 10 minutes
});
// send an event record with 'tag.label'
logger.emit('label', {record: 'this is a log'});
Instance style
var logger = require('fluent-logger').createFluentSender('tag_prefix', {
host: 'localhost',
port: 24224,
timeout: 3.0,
reconnectInterval: 600000 // 10 minutes
});
The emit method has following signature
.emit([label string], <record object>, [timestamp number/date], [callback function])
Where only the record
argument is required. If the label is set it will be
appended to the configured tag.
Logging Library Support
log4js
Before using [log4js] support, you should install it IN YOUR APPLICATION.
var log4js = require('log4js');
log4js.addAppender(require('fluent-logger').support.log4jsAppender('mytag', {
host: 'localhost',
port: 24224,
timeout: 3.0
}));
var logger = log4js.getLogger('foo');
logger.info('this log record is sent to fluent daemon');
You can add log level after tag automatically.
var log4js = require('log4js');
log4js.addAppender(require('fluent-logger').support.log4jsAppender('mytag', {
host: 'localhost',
port: 24224,
timeout: 3.0,
levelTag: true
}));
var logger = log4js.getLogger('foo');
logger.info('this log record is sent to fluent daemon');
If levelTag
is true
, tag is "mytag.INFO". If levelTag
is false
, tag is "mytag".
You can handle inner events such as 'error' it is raised when fluentd is down.
var log4js = require('log4js');
var appender = require('fluent-logger').support.log4jsAppender('mytag', {
host: 'localhost',
port: 24224,
timeout: 3.0
});
appender.on('error', function(err) {
// Handle err object
console.log(err);
});
log4js.addAppender(appender);
winston
Before using winston support, you should install it IN YOUR APPLICATION.
var winston = require('winston');
var config = {
host: 'localhost',
port: 24224,
timeout: 3.0
};
var fluentTransport = require('fluent-logger').support.winstonTransport();
var logger = new (winston.Logger)({
transports: [new fluentTransport('mytag', config), new (winston.transports.Console)()]
});
logger.log('info', 'this log record is sent to fluent daemon');
logger.info('this log record is sent to fluent daemon');
stream
Several libraries use stream as output.
var sender = require('fluent-logger').createFluentSender('tag_prefix', {
host: 'localhost',
port: 24224,
timeout: 3.0,
reconnectInterval: 600000 // 10 minutes
});
var logger = new Console(sender.toStream('stdout'), sender.toStream('stderr'));
logger.log('this log record is sent to fluent daemon');
Options
tag_prefix
The tag prefix string.
You can specify null
when you use FluentSender
directly.
In this case, you must specify label
when you call emit
.
host
The hostname. Default value = 'localhost'.
See socket.connect
port
The port to listen to. Default value = 24224.
See socket.connect
path
The path to your Unix Domain Socket.
If you set path
then fluent-logger ignores host
and port
.
See socket.connect
timeout
Set the socket to timetout after timeout
milliseconds of inactivity
on the socket.
reconnectInterval
Set the reconnect interval in milliseconds. If error occurs then reconnect after this interval.
requireAckResponse
Change the protocol to at-least-once. The logger waits the ack from destination.
ackResponseTimeout
This option is used when requireAckResponse is true. The default is 190. This default value is based on popular tcp_syn_retries
.
License
Apache License, Version 2.0.
Abour NodeJS versions
This package is compatible with NodeJS versions > 4.