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choreo

Status

This project is in its infancy. If you would like to know more, please see Contributing below.

Synopsis

The Choreo Framework is a microservices framework for assisting in the development of robotics and Internet-of-things applications. While it is lightweight, it intends to act as a more robust framework than Seneca.js, a web-based microservices toolkit, and a more flexibile, modern, and lightweight approach than ROS ("Robot Operating System) yet, in idea, it borrows from both.

One way to think of Choreo is as an SOA (Service-Oriented Architecture) without centralization. What this means is that a network of services using the Choreo framework self-organize themselves as peers, and establish communications across these channels using the GOSSIP protocol to communicate events, whereby applications within the network can respond and effect action on the network. (More information below.)

Language

While the framework itself is built in Node.js, the application is built with convention over configuration in mind, similar to Rails or Sails.js.

This framework is currently intended to be able to work with any software written in JavaScript or C/C++ (using ffi, SWIG, emscripten, or similar) allowing integration with most low-level or robotics systems out there. There are also probably a handful of ways to compile your language of choice into JavaScript or to create bindings in order to integrate, but the goal will be to eventually create several ports of integration wares, freeing users of adherance to a single language. See Contributing for ways which you can help.

Getting Started

Installation

Install globally to run from anywhere:

npm install -g choreo

Or, install locally, and add ./node_modules/.bin to your PATH:

npm install choreo
export PATH="$PATH:./node_modules/.bin"

Creating a project

A Choreo project can contain several apps, each performing a specific function:

choreo new projectName

This will create a new project in the projectName directory.

More coming soon...

Architecture

Upon executing choreo graph the application launches the application stack and a peer server, which begins listening for peers. When a peer message is broadcasted on the configured port, the application will attempt to decrypt it using the configured means, and upon success, will attempt a connect with the peer server. Upon launch, a host and port may be specified, allowing for a peer network connection to establish across subnets.

Once the connection is established, a peer-connect event signal goes out to the applications, allowing for them to handle any connections.

+----------+  +--------------+   +----------+
|          |  |--------------|   |          |
|  Launch  <---|choreo graph||   |  Listen  |
|   app    |  |--------------| +->   for    |
|  stack   |  +--------------+ | |  peers   <---+
|          |         |         | |          |   |
+----+-----+    +----v-----+   | +-----+----+   |
     |          |          |   |       |        |
     |          |  Launch  |   | +-----v-----+  |
     |          |   peer   +---+ |           |  |
     |          |  server  |     |  Decrypt  |  |
     |          |          |     |   peer    |  |
     |          +----------+     |  message  |  |
 +---v----+                      |           |  |
 |        |    +------------+    +-----+-----+  |
 |  App   |    |            |          |        |
 |  -to-  |    | Establish  |    +-----v-----+  |
 |  peer  <----+   peer     <----+ Validate  +--+
 |  init  |    | connection |    +-----------+
 |        |    |            | Success        Fail
 +---+----+    +------------+
     |
     |       +----------------+
     |       |----------------|
     +-------->   Launched   ||
             |----------------|
             +----------------+

Once a connection is established on the peer network, an application (or, microservice) can begin serving connections to the peer network. These communications may then exist as peer-to-peer communications, passed through the middleware stack, or as self-standing applications, only tying into other microservices on the peer network as the backend to an external, or front-facing service. The backend can be used to share resources such as authentication, data storage, or even access to a load balanced farm of web scrapers.

All applications on the peer network are assumed to use the same middlewares, in order to "speak" the same lingo.

                             +--------------------+
                             |     Middleware     |
                             +--------------------+
                             | +----------------+ |
                             | |   Encryption   | |
                             | +----------------+ |
                             | +----------------+ |    Peer
                         XXXXX | Authentication | |   Network
                         X   | +----------------+ | <--------->
                         X   | +----------------+ |
+--------------------+   X   | |    Logging     | |
|      Services      |   X   | +----------------+ |
+--------------------+   X   | +----------------+ |
| +----------------+ |   X   | | Comm. Protocol | |
| |   Encrypt lib  | |   X   | +----------------+ |
| +----------------+ |   X   +--------------------+
| +----------------+ XXXXX             |
| | Data store lib | |                 | Request
| +----------------+ |                 |
| +----------------+ |             +---v----+
| | Authentication | |             |        |
| +----------------+ |             | Rules  |
| +----------------+ XXXXX         | Engine |
| |  MessagePack   | |   X         |        |
| +----------------+ |   X         +---+----+
| +----------------+ |   X             |
| |  Requests lib  | |   X             | Handlers
| +----------------+ |   X             |
+--------------------+   X   +---------v---------+
                         X   | Application Stack |
                         X   +-------------------+      WEB
                         X   | +---------------+ |       +
                         X   | |     Echo      | |       |
                         X   | +---------------+ |       |
                         XXXXX +---------------+ |       |
                             | |   REST API    <------------->
                             | +---------------+ |       |
                             | +---------------+ |       |
                             | |  Web Scraper  +------------->
                             | +---------------+ |       |
                             +-------------------+       +

Services, as listed in the diagram, are libraries that allow for a common interface from the perspective of the middleware and applications. These can be accessed as global variables and provide access to basic functionality that is common to all parts of the application.

Contributing

In order to contribute, for the time being, please create an issue with what you would like to see. It's still pretty early in this project's initiation, so be patient with us as we try to get the ball rolling. Pull requests are welcome.

Contact Us

Please contact us at the email associated with our NPM page here, follow Robot Studio on Twitter, or submit an issue on the GitHub project page for the associated project that you would like to speak about.