winston-elasticsearch
An elasticsearch
transport for the winston logging toolkit.
Features
- logstash compatible message structure.
- Thus consumable with kibana.
- Date pattern based index names.
- Custom transformer function to transform logged data into a different message structure.
Unsupported / Todo
- Querying.
- Real buffering of messages in case of unavailable ES.
- Message batching; sending log messages as batches of 1000 messages using the clients bulk() method.
Installation
npm install --save winston winston-elasticsearch
Usage
var winston = require('winston');
var Elasticsearch = require('winston-elasticsearch');
var esTransportOpts = {
level: 'info'
};
winston.add(winston.transports.Elasticsearch, esTransportOpts);
// - or -
var logger = new winston.Logger({
transports: [
new Elasticsearch(esTransportOpts)
]
});
Options
level [info] Messages logged with a severity greater or equal to the given one are logged to ES; others are discarded.indexPrefix [logs] the prefix to use to generate the index name according to the pattern <indexPrefix>-<indexSuffixPattern>.indexSuffixPattern [YYYY.MM.DD] a Moment.js compatible date/ time pattern.messageType [log] the type (path after the index path) under which the messages are stored under the index.fireAndForget [false] if set to true, a callback function passed to the log() function is immediately executed without a parameters.transformer [see below] a transformer function to transform logged data into a different message structure.ensureMappingTemplate [true] If set to true, the given mappingTemplate is checked/ uploaded to ES when the module is sending the fist log message to make sure the log messages are mapped in a sensible manner.mappingTemplate [see file index-template-mapping.json file] the mapping template to be ensured as parsed JSON.client An elasticsearch client instance. If given, all following options are ignored.clientOpts An object hash passed to the ES client. See its docs for supported options.consistency [one] The consistency hint used to store messages in ES. Possible values one, quorum, all.
Important
When changing the indexPrefix and/ or the transformer, make sure to provide a matching mappingTemplate.
Transformer
The transformer function allows to transform the log data structure as provided by winston
into a sturcture more appropriate for indexing in ES.
The default transformer function's transformation is shwon below.
Input:
{
"message": "Some message",
"level": "info",
"meta": {
"method": "GET",
"url": "/sitemap.xml",
...
}
}
}
Output:
{
"@timestamp": "2015-09-30T05:09:08.282Z",
"message": "Some message",
"severity": "info",
"fields": {
"method": "GET",
"url": "/sitemap.xml",
...
}
}
The @timestamp is generated in the transformer.
Note that in current logstash versions, the only "standard fields" are @timestamp and @version,
anything else ist just free.
A custom trunsformer function can be provided in the options hash.
Events
error: in case of any error.
Example
An example assuming default settings.
Log Action
logger.info('Some message', <req meta data>);
Generated Message
The log message generated by this module has the following structure:
{
"@timestamp": "2015-09-30T05:09:08.282Z",
"message": "Some log message",
"severity": "info",
"fields": {
"method": "GET",
"url": "/sitemap.xml",
"headers": {
"host": "www.example.com",
"user-agent": "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)",
"accept": "*/*",
"accept-encoding": "gzip,deflate",
"from": "googlebot(at)googlebot.com",
"if-modified-since": "Tue, 30 Sep 2015 11:34:56 GMT",
"x-forwarded-for": "66.249.78.19"
}
}
}
Target Index
This message would be POSTed to the following endpoint:
http://localhost:9200/logs-2015.09.30/log/
