dockaless

Dockaless - Serverless Docker functions

Integrate Docker containers into a serverless platform or a lambda-based flow via IOpipe.

Examples:

Create a serverless function:

var Dockaless = require("dockaless")

var dals = Dockaless({
  protocol: 'https',
  host: '127.0.0.1',
  port: process.env.DOCKER_PORT || 2375,
  ca: fs.readFileSync('ca.pem'),
  cert: fs.readFileSync('cert.pem'),
  key: fs.readFileSync('key.pem')
})

export.handler = dals.make_lambda("ubuntu", [ "whoami" ])

Resizing videos with FFmpeg:

This may be leveraged with the IOpipe library to chain execution with local functions, remote functions, and APIs.

var iopipe = require("iopipe")()
var Dockaless = require("dockaless")
var dals = Dockaless()

export.handler = iopipe.define(
  iopipe.property("url"),
  iopipe.fetch,
  dals.make_lambda("ffmpeg", [ "-i", "pipe:0", "-vf", "scale=320:240", "pipe:1" ])
)

This example accepts a JSON document containing a "url" key. A video is fetched from this URL and scaled (resized) using ffmpeg. The video is piped back over the network to the caller, but a script could continue by saving this somewhere (such as S3) as in the following example.

Parallelization

This library combined with the IOpipe library can be used to easily build parallelized tasks requiring use of containerized applications.

The following example is similar to the previous, but converts an array of videos, saves them to storage, and returns URLs to the uploaded content.

var AWS = require('aws-sdk');
var iopipe = require("iopipe")()
var Dockaless = require("dockaless")
var crypto = require("crypto")

var dals = Dockaless()
var s3 = new AWS.S3();

function put_bucket(event, context) {
  s3.createBucket({Bucket: event.bucket}, function() {
    var params = {Bucket: event.bucket, Key: event.key, Body: event.body};
    s3.putObject(params, function(err, data) {
        if (err)
            context.fail(err)
        else
            context.succeed(event)
     });
  });
}

export.handler = iopipe.define(
  iopipe.property("urls"),
  iopipe.map(
    iopipe.fetch,
    dals.make_lambda("ffmpeg", [ "-i", "pipe:0", "-vf", "scale=320:240", "pipe:1" ]),
    (event, context) => {
      var video_hash = crypto.createHash('sha256').update(event).digest('hex')
      put_bucket({
        bucket: "your_bucket",
        key: video_hash
      }, context)
    },
    (event, callback) => {
      callback(s3.getSignedUrl('getObject', event))
    }
  )
)

Reference

class Dockaless(dockerode_opts)

If dockerode options are not provided, local environment variables will be used. Typically, this will attempt to manage a local Docker daemon via its Unix socket.

Current options are:

• host
• port
• ca
• cert
• key

See dockerode documentation for more details.

method Dockaless.make_lambda(image, cmd)

Image is the name of a Docker image.

Cmd are the arguments for the image, overriding CMD. Depending on if there is an entrypoint defined, this either passes arguments to the entrypoint, or executes the command inside the container. (This is standard Docker behavior)

License

Apache 2.0