Server Side Logger

Server-side logging, logs in console by default. In production mode it will send the logs to Kibana via logstash

Installing

Add the module to your dependencies using yarn

npm install node-server-logger --save

yarn add node-server-logger

How to use the logger

Import the logger in your app

import Logger from 'node-server-logger'

const Logger = require('node-server-logger')

Setting up your logger

The logger accepts the following arguments

const logger = Logger('name', 'mode', 'level', {options})

1. name - string (required) - name of the logger
2. mode - string (required) - by default is set to development this will log in the browser console. In production the logger will log to Kibana
3. level - string (required) - the logger follow the bunyan log levels. Setting a logger instance (or one of its streams) to a particular level implies that all log records at that level and above are logged. E.g. a logger set to level "info" will log records at level info and above (warn, error, fatal). At the moment the level need's to be passed as a string but this can (and probably should) be changed to a number in future versions for easier management and testability

• "error" (50): Fatal for a particular request, but the service/app continues servicing other requests. An operator should look at this soon(ish).
• "warn" (40): A note on something that should probably be looked at by an operator eventually.
• "info" (30): Detail on regular operation.
• "debug" (20): Anything else, i.e. too verbose to be included in "info" level.

4. 'options' - object (optional)- you can pass the following options:

• 'logstashHost' - string - a logstash url to send the log's to
• 'serializers' - object - the logger follows the Bunyan concept of "serializers" to produce a JSON-able object from a JavaScript object, so you can easily do the following:

log.info({ctx: <ctx object>}, 'something about handling this request')

The logger comes with ctx serializer that will serialize the koa context object and will pass the request.method, request.url, response.status, response.header['content-type'] and response.header['content-length']. You can use it like this:

import Logger, { ctxSerializer } from 'rulsoft-server-logger'

// define your logger
const logger = Logger('name', 'console', 'info', {serializers: { ctx: ctxSerializer })

// And then in your logger pass the ctx object like this
logger.info({ctx: ctx}, 'Some info with ctx details')

You can override the default ctxSerializer or you can write your own serializers like this:

import Logger from 'rulsoft-browser-logger'

const someUser = {
// Some object containig data for a user that you want to log
}

function userSerializer(someUser) {
    return {
        name: someUser.name,
        addres: someUser.addres,
        phone: someUser.phone
    }
}

const logger = Logger('someLogger', 'console', 'info', { logstashHost: 'http://logstashHost', serializers: {user: userSerializer} })

logger.info({user: someUser}, 'Something happened')

Running the tests

TODO there are currently no test we will need to add some

Break down into end to end tests

Explain what these tests test and why

Give an example

And coding style tests

Explain what these tests test and why

Give an example

Built With

• browser-bunyan - This package is an adaptation of, the Node logging library, Bunyan but specifically for the browser.
• lodash/fp A modern JavaScript utility library delivering modularity, performance & extras.
• detect-browser This is a package that attempts to detect a browser vendor and version (in a semver compatible format) using a navigator useragent in a browser or process.version in node.

Authors

Velizar Mihaylov