eslogger


Logging, esse

This is a light wrapper for sending data to Elasticsearch in a predictable manner.
It uses the Elasticsearch JS Client and accepts all the same arguments for configuration

Main features:

- Daily log indexes using a logstash-style naming with your supplied prefix
- Map Index creation and update capabilites (to make sure your data gets digested the way you like)
- Buffering and Bulk Insert by default, to decouple log load from ES connections.
- fine-grained filtering for particular object types, e.g. http request objects (built in)
- user-defined filtering - create a function that returns an object, and it will be matched to incoming arguments

Installation

``npm install eslogger --save`

Example Usage

Put this in a script, and edit the hosts array to point at a legit Elasticsearch destination, then run it.
It will start a webserver that you can browse to at 127.0.0.1:1337. Each time you visit that page, you'll
be creating a "hit" document. Note the following:

- Set dryrun:false if you want to actually send data out.
- filters:[null,'req'] defines how the arguments are handled when calling esl.log('hit',{foo:'bar'},req);
- null means no filtering,
- 'req' means use the built-in request object filter (currently the only built-in filter)
- supply your own filter function(s), e.g. function(ob){ return {quux:ob.quux}; }


`javascript

var prefix = "thefoobar"
var settings = {
dryrun : true,
verbose : true,
prefix : prefix,
filters : [null,'req'],
hosts : [
{ host: 'es-server-1.my-es-cluster.com',port: 9200},
{ host: 'es-server-2.my-es-cluster.com',port: 9200}
],
mapping : {
"template" : prefix + "-*",
"order": 0,
"settings": {},
"mappings": {
"hit" : {
"properties":{
"id" : {"index": "not_analyzed", "type": "string"},
"domain_name" : {"index": "not_analyzed", "type": "string"},
"browser" : {"index": "not_analyzed", "type": "string"},
"http_referer" : {"index": "not_analyzed", "type": "string", "ignore_above": 512},
"http_user_agent" : {"index": "not_analyzed", "type": "string", "ignore_above": 256},
"ip_address" : {"index": "not_analyzed", "type": "string"},
"server" : {"index": "not_analyzed", "type": "string"},
"querystring" : {"index": "not_analyzed", "type": "string", "ignore_above": 256},
"os.family" : {"index": "not_analyzed", "type": "string"},
}
},
},
"aliases": {}
}
};
var esl = require('eslogger').ESLogger(settings);
esl.mapping();

// set up an example web service to do some logging
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');


esl.log('hit',{foo:'bar'},req);


}).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');

``