Microlauncher NPM

microlauncher.js

Node.js Module for lauching microservices. Applicable for application where "main application" should launch and control (later shutdown of) these sub-microservices. Microservices should (at this time):

reside on the same server host as "main app"
be launchable as standalone excutable presenting separate process)

Benefits of microlauncher and microservices in general

Separate process with potential to run on a separate CPU core
Separated logging (esp. applicable to PM2)
Automatic control of startup and stopping of sub-microservices along with main app server.

Microservice Configuration

Example of embedding microservice config into you applications main config:

 {
   "httpport" : 3000,
   "jsonindent": 2,
   ....
   "submicroservices": [
     {"id": "loginserv", "script": "login.serv.js", "runmode": "pm2"},
     {"id": "DAQ",       "script": "datalogging.serv.js", "runmode": "pm2"},
     {"id": "cronctrl",  "script": "croncontrol.serv.js", "runmode": "pm2", "disa": 1}
   ]
   ...
 }

Using Module API

Within main app server you'd launch sub-microservices by:

 var ml = require("microlauncher");
 // Per previous example on config ...
 var launcher = new ml.MicroLauncher(cfg.microservices, {"runmode": "pm2", "debug": 1});
 // Launch all non-disabled ones
 launcher.runsubservices();

Troubleshooting microservice starting problems

Problems with `Error: listen EADDRINUSE 127.0.0.1:...`

Port is reserved on the current host
Track process that is holding it by (e.g. port 3001): lsof -i tcp:3001
Process might will PM2 maintained and get relaunched by PM2 when killed
- Kill process by pm2 stop ... ; pm2 delete ...