JavaScript client for Sematext Logs.

Installation

npm install logsene-js --save

Usage

var Logsene = require('logsene-js')
var logger =  new Logsene ('LOGS-APP-TOKEN')
logger.log ('info', 'text message', {tags: ['a','b'], customField: 'custom-field'})

Constructor Parameters

token - Logs App token. Sign up here.
type - Optional. Default type of your logs - please note you can define Elasticsearch mapping templates in Sematext Logs
url - Sematext Logs receiver URL (e.g. if you are shipping logs to Sematext Enterprise), defaults to 'https://logsene-receiver.sematext.com/_bulk'
storageDirectory - Directory where to buffer logs in the case of failure
options:
- useIndexInBulkUrl - If set to 'false' /_bulk will be used /indexName/_bulk otherwise.
- httpOptions - general HTTP/HTTPS options for the request, e.g. SSL key,cert,passphrase,ca,rejectUNauthorized etc.
- silent - If set to true, logsene-js will not log debug and errors to stdout. Used for prod envs, but not mandatory. This is false by default.

Special fields for indexing

In general Elasticsearch > 2.3 (including Sematext Logs) does not allow fields with leading underscore or dots in field names. Logsene-js converts such fields names (e.g. removing leading underscores, and replaces dots to underscores). However, a few fields are interpreted for indexing before renaming the fields:

_type - used as '_type' in the index operation (bulk indexing)
_id - used as '_id' in the index operation (bulk indexing)

Environment variables

LOGS_TMP_DIR - Directory to store failed bulk requests, for later re-transmission. Failed requests are not stored, when LOGS_TMP_DIR is not set.
LOG_INTERVAL - Time to collect logs before a bulk request is done. Default 10000 ms
LOGS_BULK_SIZE - Maximum size of a bulk request. Default 1000.
LOGS_MAX_MESSAGE_FIELD_SIZE - maximum size of the 'message' field, default 240k
LOGS_RECEIVER_URL - URL for the Sematext Logs receiver. E.g. for Sematext Enterprise version. Defaults to Sematext Logs SaaS receiver https://logsene-receiver.sematext.com/_bulk
LOGSENE_TMP_DIR - Directory where to buffer logs if the Elasticsearch endpoint is unavailable. If this is not set, logsene-js will not buffer logs at all.
LOGS_BUFFER_ON_APP_LIMIT - default 'true'. HTTP bulk requests are retried until Sematext starts accepting logs again. Please increase your daily limit setting in Logs App settings if you see "403, App limit reached" errors. Setting the value to 'false' will disable disk buffering only for failed http requests '403, Forbidden / App limit reached'. We recommend to keep the default setting 'true' to avoid any loss of logs.
LOGS_REMOVE_FIELDS - a comma separated list of fields, which should not be logged. For nested objects use a dot notation e.g. 'reques.body,request.size'

Note: Previous versions of logsene-js used LOGSENE instead of LOGS prefix for the settings above. Logsene-js is backward compatible to previous environment variable names. However all variable names with the LOGSENE prefix are depracated and might be removed in future relases.

Security

HTTPS is enabled by default
Environment variables for Proxy servers:
- For HTTPS endpoints (default): HTTPS_PROXY / https_proxy

        export HTTPS_PROXY=https://my-ssl-proxy.example
        export HTTPS_PROXY=http://my-proxy.example

For HTTP endpoints (e.g. On-Premises): HTTP_PROXY / http_proxy

        export HTTP_PROXY=http://my-proxy.example
        export HTTP_PROXY=https://my-ssl-proxy.example

Other related modules

Please check winston-logsene a transport layer for the winston logging framework.
Please see bunyan-logsene a transport layer for the bunyan logging framework.