FlowFuse Project Nodes

Node-RED instances running within FlowFuse include a set of nodes that make it very quick and easy to securely send and receive messages between different instances in a team.

The nodes act in a similar way to the Node-RED Link nodes, but by allowing the links to extended between different instances and devices, they open up a wide range of possibilities.

For example, a single Node-RED instance may contain a set of utility flows that you want to reuse in other instances. Rather than copy the flows around, the Project Nodes allow you to easily call those flows and get the result back.

The project nodes are only available in the Team and Enterprise tiers of FlowFuse.

Nodes

There are three nodes in this collection:

  • Project In - listens for messages being broadcast by other Node-RED instances, or for messages being sent just to this instance
  • Project Out - sends messages to other Node-RED instances
  • Project Call - sends messages to other Node-RED instances and waits for a response

The nodes send the whole msg object. Due to the way the nodes encode messages, there are some data types that do not get sent. For example, the msg.req/msg.res properties used by the core HTTP nodes will not be sent. Instead, they are temporarily removed from the message and re-attached when the message is received back.

Each node is configured with a topic on which it either sends or receives messages on. This is similar in concept to MQTT topics - although the nodes do not currently support using MQTT wildcards in their topics.

The Project Out nodes can either broadcast messages on a topic to anyone listening, or they can send messages on a topic to a specific other instance.

The Project In nodes do the opposite - they can either listen for messages being broadcast, or for messages sent directly to them.

The Project Call node can be used to send a message to another Project In node and then wait for a response, with a built-in timeout if it doesn't arrive. The response is sent back using a Project Out node configured to respond to the call node.

GitHub

The nodes are published under an Apache-2.0 license and available on GitHub.