remote-exec

Very simple wrapper for ssh2 to execute shell commands on one or more remote computers in node via SSH

install

npm install remote-exec

usage

var rexec = require('remote-exec');
rexec(hosts <string|array>, commands <string|array>, options <object>, callback <function>);

hosts

hosts can be a string, an array of strings, or an array of objects
if hosts is an array of objects, the name key of each object will be used to connect to the host

commands

commands can be a string or an array of strings
commands can also contain parameters using the {{myParameter}} syntax (see below)

options

options is the connection options object used for ssh2 with the following additions:

• the params key takes an object declaring global/default values for parameters used in commands
• the beforeEach key takes a callback function run for each host before commands are run (passed host, commands, and params objects)
• the afterEach key takes a callback function run for each host after commands are run or when an error is encountered (passed host, commands, params, and err objects)
• stdout and/or stderr can be specified to change where output from the remote hosts is sent

examples

basic

var rexec = require('remote-exec');

// see documentation for the ssh2 npm package for a list of all options 
var connection_options = {
	port: 22,
	username: 'myuser',
	privateKey: require('fs').readFileSync('~/.ssh/rsa_id'),
	passphrase: 'mypassphrase'
};

var hosts = [
	'host1.somewhere.com',
	'host2.somewhere.else.com',
	'250.110.0.13'
];

var cmds = [
	'ls -l',
	'cat /etc/hosts'
];

rexec(hosts, cmds, connection_options, function(err){
	if (err) {
		console.log(err);
	} else {
		console.log('Great Success!!');
	}
});

parameters

// commands can be parameterized using the {{parameterName}} syntax
// parameters can be set at the global or host level

// global parameters should be set via the params key of the connections options
var connection_options = {
	port: 22,
	username: 'myuser',
	privateKey: require('fs').readFileSync('~/.ssh/rsa_id'),
	passphrase: 'mypassphrase',
	params: {
		myParam: 'something',
		anotherParam: 'something else'
	}
}

// to set a parameter for a specific host:
var hosts = [
	{name: 'host1.somewhere.com', myParam: 'this overrides the global myParam value', blah: 'this is an additional parameter at the host level'},
	{name: 'host2.somewhere.else.com'} // this host will only get the global parameters
];

var cmds = [
	'echo "{{myParam}}"'
];

rexec(hosts, cmds, connection_options, function(err){
	if (err) {
		console.log(err);
	} else {
		console.log('Great Success!!');
	}
});

output

// by default all output for remote computers is routed to process.stdout and process.stderr
// but this can be overridden by passing valid writable streams to the stdout and/or stderr
// keys of the connection options

var rexec = require('remote-exec')
  , fs = require('fs');

var connection_options = {
  port: 22,
  stdout: fs.createWriteStream('./out.txt'),
  stderr: fs.createWriteStream('./err.txt')
}

rexec('myserver.com', 'cat /proc/cpuinfo', connection_options);