mmagr / flowbroker-dojot

Flow processing implementation, with hot deployment capabilities

Mashup invoker proof of concept

This repository contains the implementation for a replacement for dojot's flow/mashup processor, based on nodes that run as persistent services on the platform.

The idea here is to run each known processing node (switch, change, geo, email, etc) as a container (or set of containers) and have the mashup orchestrator invoke a stateless endpoint on such containers, chaining their responses to produce the final flow results.

Implementation

• The orchestrator itself is implemented under the directory orchestrator.
• The library that abstracts communication from the orchestrator to the nodes themselves (e.g. change, email) is implemented under lib
• A sample node implementation is found under sampleNode.

This code has been developed and tested using node v8.9.x

How to build (orchestrator)

cd orchestrator
npm install

Running

node index.js [options]

To run as a server:

node index.js -s

To run a message against a flow (sample):

node index.js -v -m '{"temperature": 22.5}' -d '18a9' -f flow.json -i 1000

This allows a processing node developer to easily test a node when used alongside the broker. For a sample flow definition file, check docs/samples/flow.json.

All the commands above will require at least a running, reachable instance of RabbitMQ at the hostname amqp.

To quickly create an environment using docker-compose, one may use the compose file (compose.yaml). For now, remember that any installed nodes must be added manually to the compose file or else the orchestrator will not be able to reach them. (developers) To allow quick prototyping and validation of the flow broker, a raw node:8 container is used, with the project's homedir mounted into it.

# -- on host --
docker-compose -p flows -f compose.yaml up -d

# spawn flowbroker within the same network
docker run --rm -it --network flows_default -v $PWD:/flowbroker node:8 bash

# -- now, within the container --
cd /flowbroker/orchestrator
npm install
node index.js -v -m '{"temperature": 22.5}' -d '18a9' -f ../docs/samples/flow.json -i 1000