a middleware file for restify to use knex as database connection

knex-restify-midleware.js

/**
 * Created by m.schultheiss on 29.01.2016.
 * References:
 * - http://restify.com/
 * - http://knexjs.org/
 * Helpers:
 * - https://github.com/trentm/node-bunyan
 * - https://lodash.com
 */
 
var knex = require("knex"),
  dbManager = require("../../config/databases"),
  _ = require("lodash");

function closeKnex(option) {
  //try to knex.destroy
  option.knex && option.knex.destroy && option.knex.destroy(function onDestroy() {
    // on success log closed connection
    if (option.log && option.log.info) {
      option.log.info({
        "note": "DB connection closed",
        "origin": "mcp-database",
        "customer": option.customer,
        "dbConfig": option.dbConfig,
        "event": "closeConnection"
      });
    } else {
      console.log("DB connection closed", {
        "customer": option.customer,
        "dbConfig": option.dbConfig
      })
    }
  });
}
exports = function(req, res, next) {
  // load config via header
  req.dbConfig = dbManager.findCustomerDB(req.headers["x-api-customers"] || req.params.customers);
  // set req.knex for later usage
  req.knex = knex(req.dbConfig);
  //create transport object
  var option = {
    "customer": req.headers["x-api-customers"] || req.params.customers,
    "dbConfig": req.dbConfig,
    "knex": req.knex
  };
  // dumping dbConfig as openConnection event, @see http://restify.com/#audit-logging
  req.log.info(_.merge(option, {
    "event": "openConnection"
  }), "db connection opened");
  // close connection once response is send
  res.once("finish", closeKnex.bind(this, _.merge(option, {
    "log": req.log
  })));
  // call to run next route
  next();
};