Documentation > Administration > Node Configuration

Node Configuration

When a node starts in standalone mode, the node will read a local configuration from a file and start services as specified in the configuration.

Configuration File Location

The local configuration of a node is defined in a JSON file .crossbar/config.json within the node directory.

The default path of the configuration file can be overridden using the --cbdir and --config options of the command line interface (CLI). See crossbar start --help.

While the local configuration is the only required file in the node directory, the directory will usually contain other files. For example, here are the contents of a typical node directory:

  • ./.crossbar/ - node directory
  • ./.crossbar/config.json - Local node configuration
  • ./.crossbar/myapp.sock - A Unix domain socket of a configured Transport
  • ./.crossbar/log - Log directory
  • ./.crossbar/log/node.log - Current log file
  • ./.crossbar/log/node.log.2014_4_26 - Archived log file
  • ./.crossbar/cookies.db - authentication cookie database
  • ./.crossbar/dhparam.pem - TLS Diffie-Hellman server parameter file
  • ./.crossbar/myserver_key.pem - TLS key of server
  • ./.crossbar/myserver_cert.pem - TLS certificate of server

Configuration File Format

A configuration is a JSON file with a top level dictionary value. The simplest valid node configuration is just:


Most of the time however, you will want to configure the processes and services running, and this is done from two sections: for the controller configuration and for the definition of workers

   "controller": {
   "workers": [

If present, controller must be a dictionary and workers, if present must be a list of dictionaries. No other attributes other than controller and workers are currently allowed.

The "workers" attribute must be a list of workers

parameter description
type Must be one of "router", "guest" or "container".
type specific Please see Router Configuration, Guest Configuration and Container Configuration.

The contents of the controller and workers section is described in the following pages:


Checking a Configuration

You can check a configuration by doing:

oberstet@corei7ub1310:~/mynode1$ crossbar check
Checking local configuration file /home/oberstet/mynode1/.crossbar/config.json
Checking process item 1 ..
Checking process item 2 ..
Checking process item 3 ..
Checking module item 1 ..
Checking realm item 1 ('realm1') ..
Checking transport item 1 ..
Ok, configuration file looks good.

crossbar check checks to see if there are any syntactical issues, e.g. invalid attributes. It will NOT catch all possible configuration issues. E.g. if you configure 2 router transports listening on the same TCP port, this will not work, but the check won't raise an error. You will only get error feedback upon starting the node.