Node JSON logger

This library provides a minimal JSON logging interface suitable for use in microservices - see the parent project here

Install

npm install --save microservice-logging

Examples of use

All of the following code can be found here

Instantiate a new logger like this:

const Logger = require('./logger')

const log = new Logger({
  now: Date.now,
  output: console,
  events: {
    startup: 'startup',
    exception: 'exception',
    httpRequest: 'HTTP request',
    query: 'SQL query'
  }
})

const service_logger = log.with({ service: 'my super service' })

You can then use the logger by invoking it like so:

log.startup.error({
  message: "Emergency! There's an Emergency going on"
})

This will output:

{"service":"my super service","timestamp":1468333486800,"event_type":"startup","severity":"ERROR","message":"Emergency! There's an Emergency going on"}

Although, obviously, the timestamp attribute will be different - this is the number of seconds since the epoch, in case you were wondering. If you want to add specific information (like request data) you can do so like this:

log.httpRequest.info({
  correlation_id: '126bb6fa-28a2-470f-b013-eefbf9182b2d',
  request: { method: 'GET' },
  response: { status: 200 }
})

Which prints:

{"service":"my super service","timestamp":1468333607265,"event_type":"HTTP request","severity":"INFO","correlation_id":"126bb6fa-28a2-470f-b013-eefbf9182b2d","request":{"method":"GET"},"response":{"status":200}}

Developing on the library

Pull Requests are most welcome - if you want to run the tests then simply:

npm test

All PRs that break the test suite will be politely declined :-)

LICENSE

See LICENSE file in parent project, but basically MIT.