w8r v4.0.1
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 anet
client to check to see if the server at the provided host:port is available everycheckInterval
ms and then fork a new node process.checkInterval:number
- amount of delay, in ms, before trying againprofile:string
- the path to the entry point for the child processprocargs:array(string)
(optional) - arguments to your commandprocopts:object
(optional) - options for thechild_process.fork
command
The serverList
array can contain two separate object types:
- paths to unix domain sockets (e.g.:
/var/run/mysql
) - objects containing a
port
andhost
key (e.g.:{port: 6379, host: 'redis'}
)
Licence
Copyright © 2016 Scripto, LLC. Apache-2.0 Licensed.