As a newbe, I tried to do my first flow using NodeRed. The installation is a Victron Cerbo GX running Venus where NodeRed is already pre-installed within the big image. Installation went through without errors. I can invoke https://10.10.20.149:1881 and enter any flow using already predefined symbols and IO by Victron Venus OS.
Unfortunately, nothing happens with the flow. Debug window shows the following text:
Your flow credentials file is encrypted using a system-generated key.
If the system-generated key is lost for any reason, your credentials
file will not be recoverable, you will have to delete it and re-enter
your credentials.
You should set your own key using the 'credentialSecret' option in
your settings file. Node-RED will then re-encrypt your credentials
file using your chosen key the next time you deploy a change.
I can ssh in and found a nodred directory. Where do I find settings.js and what to do there?
root@einstein:/data/home/nodered# find settings.js
find: settings.js: No such file or directory
root@einstein:/data/home/nodered#
The message is just a warning, not an error, you don't really need to do anything about it, the credentials will still be encrypted, just with an automatically generated key.
As a rule you should not run Node-RED as root unless you really know what you are doing and it really should be locked down with a username/password to prevent anybody else using it to run commands as root remotely. This is VERY important, if it ever exposed to the public internet.
Your find command doesn't work because that is not the correct syntax, it would be find . -name settings.js (this says starting in the current directory . look for a file called settings.js).
The file will be in the .node-red directory (note the leading . which makes the file invisible to normal directory listings (running ls -a will show even hidden files). So if Node-RED is running as root the file will be in /root/.node-red.
Nothing will happen in the flow unless it is triggered, including debug output. As an example, if you link an inject node to debug node and deploy it, that should show output when the inject button it pressed, but any other flows are likely going to only trigger on an external event, e.g. an incoming HTTP request.
I finally found /usr/lib/node_modules/node-red/settings.js beside many other locations but I am lucky that the warning is not a reason to deal with.
The reason for login as root was only to locate possible problem with settings.js what I assumed because of the warning in debug window. the Node Red flow seems not running as root itself and in my case, its not available to public and system has no entry in my reverse proxy. I simply invoked the pre installed Node Red version what comes with the Venus system.
Anyhow, the question remains why my flow is doing nothing and there are no usefull string contents displayed in the debug window beside that suspicious warning. The flow scans 4 predefined input lines where always exactly one is active. I can see the line states in the Venus device menue system. A corresponding value to the input lines should then be written into the predefined output variable "Max Inverter Power".
Almost certainly that is the wrong one. It will probably be a folder called .node-red.
The reason that there is nothing working is that your flow (or all the nodes) are disabled. Double click the Flow tab and check bottom left if it is disabled. If not then double click one of the nodes and check that.
Many thanks. All first steps are difficult. I tried this check box before but after I also have to select the "deploy" pulldown to start the flow. The nodes have now green dots beside what show its state on/off/connected. The debug window now shows the output value.
Lets see, if I am going to become a NodeRed fan in future as old assembly and C programmer. Thanks again for the startup help. The NodeRed flows remember me to data flow diagrams what I saw long ago in a old software engineering book by Tom De Marco. Probably the focus of NodeRed is not realtime control. At least I have the entrance point now to play around what is feasable with.
It depends on what you mean by 'real time'. If you want to control something with millisecond precision then probably don't use node-red, though the issue is as much the fact that the underlying OS (Debian based or Windows for example) is not real time. If you mean controlling something where the process timing is in seconds or slower, rather than milliseconds, then node-red can be suitable for that.
I recommend watching this playlist: Node-RED Essentials. The videos are done by the developers of node-red. They're nice & short and to the point. You will understand a whole lot more in about 1 hour. A small investment for a lot of gain.
