@droneblocks/node-red-dexi/src/ros2-subscribe.js

You want to make sure you don't lose any of your flow development. Make sure to map the host "flows" directory to the container directory as shown below. This will store the flow on your host machine if/when the container is destroyed.

module.exports = function (RED){
    var ROSLIB = require('roslib')

    function ROS2SubscribeNode(config) {
      RED.nodes.createNode(this, config);
      var node = this;

      node.server = RED.nodes.getNode(config.server);
      
      if (!node.server || !node.server.ros){
        return;
      }
  
      // if topic has not been advertised yet, keep trying again
      function topicQuery(topic){
        node.server.ros.getTopicType(topic.name, (type) => {
          if (!type){
            setTimeout(()=>{topicQuery(topic)}, 1000);
          } else {
            topic.subscribe(function(data){
              var o = JSON.parse(JSON.stringify(data))
              node.send({payload: o});
            });
          }
        })
      }
  
      node.server.on('ros connected', () => {
        
        node.topic = new ROSLIB.Topic({
          ros : node.server.ros,
          name : config.topicname
        });
      
        topicQuery(node.topic);
        node.status({fill:"green", shape:"dot", text:"connected"});
      });
  
      node.server.on('ros error', () => {
        node.status({fill: "red", shape:"dot", text:"error"});
      });

      node.on("close", function() {
        if (!node.server.closing){
          node.topic.unsubscribe();
        }
      });
    }
  
    RED.nodes.registerType("ros2-subscribe", ROS2SubscribeNode);
  };