Cocaine NPM | npm.io

Cocaine NodeJS Framework

Examples of usage

Create NodeJS app for Cocaine cloud

Let's start with simple NodeJS http application.

var http = require('http')

var server = new http.Server(function(req, res){
    var body = []
    req.on('data', function(data){
        body.push(data)
    })
    req.on('end', function(){
        res.writeHead(200, {
          'x-any-header': 'x-any-value',
          'content-type': 'text/plain'
        })
        res.end('hello, Cocaine!')
    })
})

server.listen(8080)

To get our app working in Cocaine cloud, let's add just a couple of things.

#!/path/to/node
var cocaine = require('cocaine')
var http = cocaine.http // monkey-patches node's original http server

var argv = require('optimist').argv //which is actually a hash
// looking like { opt: 'value'}

var worker = new cocaine.Worker(argv)

var handle = worker.getListenHandle("http") // the handle implements a
// low-level nodejs' listening tcp socket, and it makes nodejs
// understand cocaine streams.

var server = new http.Server(...) // the same thing as above

server.listen(handle) // as per [1], start listening on cocaine handle

To let the cocaine-runtime know what to run in our app, we put manifest.json:

{ "slave":"app.js" }

Since the app.js has to be an executable, we put shebang on first line and don't forget about setting an executable bit.

See the complete app here 2.

Deploy app to the cloud

git clone url/the_app
cd the_app
npm install
tar -czf ../the_app.tgz
cocaine-tool app upload -n the_app --package ../the_app.tgz --manifest manifest.json
>app the_app has been successfully uploaded

then,

cocaine-tool app start -n the_app -r default
>app the_app started
curl -v http://<cloud.front>/the_app/http/
>...

Make use of Cocaine services

var cocaine = require("cocaine")

var cli = new cocaine.Client(["localhost", 10053])

var log = new cli.Logger("myprefix") // logs lines like "myprefix/..."

cli.on('error', function(err){
    console.log('client error', err)
})

log.on('error', function(err){
    console.log('logger error', err)
})


log.connect()

log.on("connect", function() {

    cli.getServices(['geobase'], function(err, geo, ua){
        var names
        
        log.info("looking up regionId for ip 1.2.3.4")
        
        geo.region_id("1.2.3.4", function(err, regionId) {
            if(err) return _handleError(err)

            log.debug("found region %d for %s", regionId, "1.2.3.4")

            geo.names(regionId, function(err, names){
                if(err) return _handleError(err)

                log.debug("names for region %d are %s", regionId, names.join())

                geo.coordinates(regionId, function(coords){
                    if(err) return _handleError(err)

                    log.debug('coordinates for region %d are %s', regionId, coords.join())

                })
            })
        })
    })
})

function _handleError(err){
    console.log('service error', err)
}

See client-simple for complete source of the simplest cocaine client app.

Use Cocaine services from the outside of the cloud

To fully control a client to services, you can use Client. It resolves services for you, keeps services cache, and resets resolved services cache on locator disconnect.

var cli = new require('cocaine').Client()

var storage = cli.Service('storage')

storage.on('error', function(err){
    // reconnect on network error
})

storage.connect()

storage.on('connect', function(){
    storage0.write('collection','key','value', function(err){
        if(err){
            console.log('error writing to storage', err)
            return
        }
        
        console.log(done 'writing to storage')
    })
})

See client-reconnect for example of handling various socket-level failures when connecting and communicating to locator and target services.

Access your application as a Cocaine service

var cli = new require('cocaine').Client()
var app = cli.Service('the_app')

app.connect()

app.on('connect', function(){
    app.enqueue('handle','anydata', function(err, result){
        if(err) {
           console.log('app error', err)
        } else {
          console.log('app response is', result)
        }
    })
})