log.js

'use strict';

const reqContext = require('./requestContext');

function getContext () {
  // note: this is a shallow copy
  return Object.assign({}, reqContext.get());
}

function isDebugEnabled () {
  // disable debug logging by default, but allow override via env variables
  // or if enabled via forwarded request context
  return process.env.DEBUG_LOG === 'true' || reqContext.get()["Debug-Log-Enabled"] === 'true';
}

function log (level, msg, params) {
  if (level === 'DEBUG' && !isDebugEnabled()) {
    return;
  }

  let logMsg = getContext();
  logMsg.level   = level;
  logMsg.message = msg;
  logMsg.params  = params;

  console.log(JSON.stringify(logMsg));
}

module.exports.debug = (msg, params) => log('DEBUG', msg, params);
module.exports.info  = (msg, params) => log('INFO', msg, params);
module.exports.warn  = (msg, params) => log('WARN', msg, params);
module.exports.error = (msg, params) => log('ERROR', msg, params);