Lucidtail NPM | npm.io

lucidTAIL

A real-time zero-configuration web-based tail. It broadcasts events such as new lines added to any monitored files, new UDP messages, and those emitted by other EventEmitters to your browser.

`lucidtail` Command

The lucidtail command listens to specified sources and displays them in a pretty little web application (see Demo).

To quickly be able to view your logs at http://localhost:8080 (default):

npm install lucidtail -g # One time global install
lucidtail *.log

Installation

You must already have nodejs installed.

Method: Simple

To install lucidTAIL globally:

npm install lucidtail -g

This allows you to use the lucidtail command. You may need root/Administrator access, if you don't have it you can alternately get lucidTAIL from the git repository.

Method: From GIT

Clone lucidTAIL:

git clone git://github.com/davidnqd/lucidtail.git

You should now be able to use ./index.js or node index.js within the cloned directory instead of lucidtail.

Usage

Please see lucidtail --help

Examples

lucidtail will use it's default http port (8080) when running.

Monitor Files

lucidtail *.log

Monitors all files ending with '.log'.

Monitor UDP

lucidtail -u 514

Monitors UDP messages on syslog port 514 (which requires root access on most systems).

Publish on port 80

sudo lucidtail *.log -u 514 -p 80

Monitor all files ending with '.log'.
Monitor UDP messages on port 514 (syslog). * This requires root access on most systems.
Publish on port 80 * This requires root access on most systems.

Advanced Setups

Examples

The examples assume you have either added lucidtail to your package.json or executed:

npm install lucidtail

Test

require('lucidtail')()
	.use('test');

Monitors a test emitter (which sends a test message every second) and publish events on the default port (port 8080):

Raw UDP

require('lucidtail')()
	.use('udp4', 5000);

Monitors UDP messages on port 5000.

syslog

The following will display inbound syslog messages (UDP port 514) on HTTP port 80:

Notes:

This example requires lazy which is on npm.
Port 80 and 514 may require root/Administrator privileges to bind.

Example:

var lucidtail = require('lucidtail'),
	lazy = require('lazy');

// Use a simple regex to parse out the values in the message
// Not even RFC 3164, but this is just an example.
var regex = /(<\d+>)?(\w{3} +\d+ \d{2}:\d{2}:\d{2})?( \w+)?( \w+\[?\d*\]?)?: (.*)/;
var syslog = lazy(lucidtail.emitter('udp4', 514))
	.map(function(data) {
		var matches = data.data.match(regex);
		if (matches) {
			if (matches[1])
				data.pri = matches[1].replace(/[<>]/g, '');
			if (matches[2])
				data.date = matches[2];
			if (matches[3])
				data.host = matches[3].substring(1);
			if (matches[4])
				data.application = matches[4].substring(1);
			if (matches[5])
				data.msg = matches[5];
		}
		return data;
	});

// Create aggregate emitter
var emitter = lucidtail(80)
	// Listen to a test emitter
	.listen(syslog);

API

The API is exposed by require('lucidtail') and is still rapidly evolving, but the gist of it is:

`lucidtail([server|port=8080][, options])`

A convenience method which returns an instance of lucidtail.Aggregator. All events emitted by the returned lucidtail.Aggregator will be sent through a socket.io socket to users.

'server|port': either a http.Server or a port (default = 8080)
'options': the options object 'host': http host to listen to (default = INADDR_ANY) 'of': socket.io namespace to use

`lucidtail.Aggregator`

A sub class of events.EventEmitter.

`lucidtail.Aggregator.pipe(destination[, events])`

Forward events to a destination events.EventEmitter.

destination: Destination events.EventEmitter
events: An array of events to forward (default: 'data', 'error') or an object whose key/value pairs are used to map source events (keys) to destination events (value).

`lucidtail.Aggregator.listen(source[, events])`

The opposite of lucidtail.Aggregator.pipe(destination[, events]).

`lucidtail.emitter(name[, arg1, arg2])`

A connivence method which creates events.EventEmitters.

name object tail: tail a file specified by arg1 (default: 'test') test: Emit a test message every second udp: Emit inbound UDP messages on a port specified by arg1 socketio: Pipes emitted events to a socket.io socket servicing http.Server arg1.