SUP

SUP is a command-line tool for interacting with a 2600Hz node.

Talking to 2600Hz

SUP is built to talk to Erlang virtual machines (BEAM) and provide the user (you) with a command-line interface that is more familiar than connecting to the VM’s shell and executing Erlang code directly on the VM.

SUP also provides some protection from foot-guns.

2600Hz provides a number of code modules, ending with the suffix _maintenance, callable from the SUP tool. Other modules can be called (provided any arguments from SUP are in the proper format and type expected by the Erlang module) as well but the maintenance mdoules are specifically built for SUP calls.

Command line options

sup -h
Usage: sup [-?] [-n [<node>]] [-c [<cookie>]] [-t [<timeout>]] [-v]
           [<module>] [<function>] [-s [<use_short>]] [args ...]

  -?, --help       Show the program options
  -n, --node       Node name [default: kazoo_apps]
  -c, --cookie     Erlang cookie [default: change_me]
  -t, --timeout    Command timeout [default: 0]
  -v, --verbose    Be verbose
  <module>         The name of the remote module
  <function>       The name of the remote module's function
  -s, --use_short  Force using shortnames [default: undefined]

Bash auto-completion

From the 2600Hz root, you can run make sup_completion to generate a {ROOT}/sup.bash file that will contain the current auto-completion options for SUP. These are the maintenance modules and some other oft-used modules (such as for setting system_config values).

Remote hosts

The ability to connect to remote hosts has been removed from SUP command for security reasons. For connecting to remote Erlang host, the port for the EPMD service, 4369, needed to be exposed in firewalls. In addition, the distribution ports given to the Erlang VMs (that SUP uses to connect on), would need to be opened up as well. As Erlang VMs are only “protected” by a cookie, this was not sufficiently secure enough to allow these ports to be open to the wider Internet.

If you need to connect to a remote Erlang node, the best and secure alternative is to SSH to the host and run SUP locally. You could also play with reverse tunnels but that can get tricky if you have EPMD running locally.

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