Visual bot creation using Node-RED

It's very easy to create simple interactions with a Matrix chatroom without programming. Discover Node-RED, a visual tool to wire together APIs. We have extended Node-RED with nodes to listen and talk in Matrix chatrooms.

How to install Node-RED

Node-RED is an open-source web application that is easy to deploy as a Docker container. You can deploy it locally on your computer using Docker. Or you can use any of the available online Docker hosting offers, such as sloppy.io or hyper_.

The custom Docker image which includes Node-RED plus additional nodes is available on our DockerHub repository

Install Node-RED on your local machine

First, install Docker if you haven't done it yet.

Then you just need to run:

    docker run -it -p 1880:1880 --name mynodered maski/node-red-docker

Let's dissect that command...

    docker run      - run this container... and build locally if necessary first.
    -it             - attach a terminal session so we can see what is going on
    -p 1880:1880    - connect local port 1880 to the exposed internal port 1880
    --name mynodered - give this machine a friendly local name
    maski/node-red-docker - the image to base it on

Running that command should give a terminal window with a running instance of Node-RED

    Welcome to Node-RED
    ===================
    8 Apr 12:13:44 - [info] Node-RED version: v0.14.5
    8 Apr 12:13:44 - [info] Node.js  version: v4.4.7
    .... etc

You can then browse to http://{host-ip}:1880 to get the familiar Node-RED desktop.

Install Node-RED on an online Docker hosting

A quick and easy way to host it online is to use Sloppy.io's 1-month free trial. Once you have created an account, go to the Dashboard and create a new project, a new service inside it, and an app within it using maski/node-red-docker as image path and pick a domain URI, such as my-node-red.sloppy.zone. Deploy the project, and you will have your own Node-RED server up and running at the selected URI.

How to use Node-RED

You can learn how to use Node-RED by following the Node-RED getting started guide. You can find additional tutorials here.

How to use the Matrix nodes in Node-RED

The package node-red-contrib-matrixbot, included in the abovementioned Docker image, adds 3 node types to the Node-RED palette (Matrix section, at the bottom):

Matrix sender: sends messages from your Node-RED flow to the chatroom
Matrix receiver: listens to messages in a chatroom and sends them to your Node-RED flow
Matrix command: listens only to messages starting with a specific command and sends them to your Node-RED flow

All of these nodes require a Matrix Configuration with the following settings:

User ID: the user ID in the matrix server, for instance @mybot:matrix.org
Access token: the access token of the user in the matrix server
Server URL: URL of the Matrix homeserver, e.g. https://matrix.org
Room ID: ID of the chatroom to join when starting. If no room is specified, it will automatically join any room where it is invited

A simple application

We will create a simple application that will send messages to a chatroom whenever a RSS feed gets updated:

First, invite the bot to the chatroom where it will be speaking and note the room ID.
In Node-RED, pick the Feedparse node from the palette (you can filter by typing the first letters at the top) and drop it on the canvas
Double-click on it to configure it and then enter a RSS feed, for instance http://rss.nytimes.com/services/xml/rss/nyt/World.xml. Give the node a name if you want and then click Done.
Pick the Matrix sender node and drop it on the canvas. Link the output of the previous node to its input.
Now double click on it and click on the pencil next to Connection to configure the Matrix settings. Follow the instructions described in the previous section.
Once you're done, click the Deploy button at the top right corner and you're done!
If you want to show also the link in the resulting message, try adding a function node in the middle with the following code:

var title = msg.article.title;
var link = msg.topic;
msg.payload = title + " \n" + link;
return msg;

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