Prepare a project folder
Start by setting up a local NoFlo Node.js project. For example:
$ mkdir my-project $ cd my-project $ npm init $ npm install noflo --save $ npm install noflo-nodejs --save
Continue by installing whatever NoFlo component libraries you need, for example:
$ npm install noflo-core --save
If you want, this is a great time to push your project to GitHub.
Starting the runtime
Once you have installed the runtime, it is time to start it:
$ node node_modules/.bin/noflo-nodejs --secret some-password
This will start a WebSocket-based NoFlo Runtime server. When started, it will output an URL with the connection details needed by Flowhub.
Copy paste this URL into the browser. The Flowhub IDE will open, and automatically connect to your runtime. To make changes hit 'Edit as Project'. You should be able to see available components and build up your system.
Securing the runtime connection
The noflo-nodejs runtime can be secured using TLS. Place the key and certificate files somewhere that noflo-nodejs can read, and then start the runtime with the
--tls-key and --tls-cert` options.
For example, to use self-signed keys, you could do the following:
$ openssl genrsa -out localhost.key 2048 $ openssl req -new -x509 -key localhost.key -out localhost.cert -days 3650 -subj /CN=localhost $ noflo-nodejs --tls-key=localhost.key --tls-cert=localhost.cert
Note: browsers may refuse to connect to a WebSocket with a self-signed certificate by default. You can visit the runtime URL with your browser first to accept the certificate before connecting to it in the IDE.
Starting an existing graph
If you want to run an existing graph, you can use the
noflo-nodejs --graph graphs/MyMainGraph.json
If you want the process to exit when the network stops, you can pass
noflo-nodejs supports flowtrace allows to trace & store the execution of the FBP program,
so you can debug any issues that would occur. Specify
--trace to enable tracing.
$ noflo-nodejs --graph graphs/MyMainGraph.json --trace
If you are running in
--batch mode, the file will be dumped to disk when the program terminates.
Otherwise you can send the
SIGUSR2 to trigger dumping the file to disk.
$ kill -SIGUSR2 $PID_OF_PROCESS ... Wrote flowtrace to: /tmp/1151020-12063-ami5vq.json
You can now use various flowtrace tools to introspect the data.
For instance, you can get a human readable log using
$ flowtrace-show /tmp/1151020-12063-ami5vq.json -> IN repeat CONN -> IN repeat DATA hello world -> IN stdout CONN -> IN stdout DATA hello world -> IN repeat DISC -> IN stdout DISC
Host address autodetection
noflo-nodejs will attempt to autodetect the public hostname/IP of your system.
If this fails, you can specify
--host myhostname manually.
noflo-nodejs will ping Flowhub registry periodically to signal aliveness. To disable this behavior, set
Persistent runtime configuration
Settings can be loaded from a
By default the configuration will be read from the current working directory,
but you can change this by setting the
PROJECT_HOME environment variable.
This file will be automatically saved when you run noflo-nodejs, meaning that settings like runtime ID and secret will be persisted between runs.
Environment variables and command-line options will override settings specified in config file.
Since the values are often machine and/or user specific, you usually don't want to add this file to version control.