https://github.com/scriptollc/w8r

✋ Wait for it...
https://github.com/scriptollc/w8r

Last synced: 10 months ago
JSON representation

✋ Wait for it...

• Host: GitHub
• URL: https://github.com/scriptollc/w8r
• Owner: scriptoLLC
• License: other
• Created: 2016-08-09T18:27:02.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2018-10-08T17:32:45.000Z (over 7 years ago)
• Last Synced: 2025-08-09T18:52:15.947Z (10 months ago)
• Language: JavaScript
• Homepage:
• Size: 10.7 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

          
# w8r

[![Greenkeeper badge](https://badges.greenkeeper.io/scriptoLLC/w8r.svg)](https://greenkeeper.io/)

[![Build Status](https://travis-ci.org/scriptoLLC/w8r.svg?branch=master)](https://travis-ci.org/scriptoLLC/w8r)

Poll to see if a service is running, and once it is, fork a new node process

## Huh?

`(net|http).createServer()#listen` is async. Sometimes you want to do something

but only after the a server has started. You can just hope it starts in time,

or you can use this.

Also useful for docker-compose -- if you have dependent containers, docker will

wait for the container to be ready, but it doesn't know if the service is

ready yet.  This makes sure your app won't start until the service it depends

on is available.

## Usage

`npm install --save w8r`

```

const w8r = require('w8r')

const serverlist = [{host: 'redis', port: 6379}, '/var/run/mysql']

w8r(50, serverlist, 'start-server.js', (err, child) => {

  // both services are up and running!

  // and child is your child process you started!

})

```

## API

* `w8r(checkInterval:number, serverList:array, procfile:string, procargs?:array(string), procopts?:object, cb:function)`

Spawn a `net` client to check to see if the server at the provided host:port is

available every `checkInterval` ms and then fork a new node process.

* `checkInterval:number` - amount of delay, in ms, before trying again

* `profile:string` - the path to the entry point for the child process

* `procargs:array(string)` (optional) - arguments to your command

* `procopts:object` (optional) - options for the [`child_process.fork`](https://nodejs.org/api/child_process.html#child_process_child_process_fork_modulepath_args_options) command

The `serverList` array can contain two separate object types:

* paths to unix domain sockets (e.g.: `/var/run/mysql`)

* objects containing a `port` and `host` key (e.g.: `{port: 6379, host: 'redis'}`)

## Licence

Copyright © 2016 Scripto, LLC. Apache-2.0 Licensed.