ssh-pool

Run remote commands over a pool of server using SSH.

npm install ssh-pool

Usage

import { ConnectionPool } from 'ssh-pool'
 
const pool = new ConnectionPool(['user@server1', 'user@server2'])
 
async function run() {
  const results = await pool.run('hostname')
  console.log(results[0].stdout) // 'server1'
  console.log(results[1].stdout) // 'server2'
}

new Connection(options)

Create a new connection to run command on a remote server.

Parameters:

@param {object} options Options
@param {string|object} options.remote Remote
@param {Stream} [options.stdout] Stdout stream
@param {Stream} [options.stderr] Stderr stream
@param {string} [options.key] SSH key
@param {function} [options.log] Log method
@param {boolean} [options.asUser] Use a custom user to run command
@param {number} [options.verbosityLevel] SSH verbosity level: 0 (none), 1 (-v), 2 (-vv), 3+ (-vvv)

The remote can use the shorthand syntax or an object:

// You specify user and host
new Connection({ remote: 'user@localhost' })
 
// You can specify a custom SSH port
new Connection({ remote: 'user@localhost:4000' })
 
// You can also define remote using an object
new Connection({
  remote: {
    user: 'user',
    host: 'localhost',
    port: 4000,
  },
})
 
// When defined as an object you can add extra ssh parameters
new Connection({
  remote: {
    user: 'user',
    host: 'localhost',
    port: 4000,
    extraSshOptions: {
      ServerAliveInterval: '30',
    }
  },
})

The log method is used to log output directly:

import { Connection } from 'ssh-pool'
 
const connection = new Connection({
  remote: 'localhost',
  log: (...args) => console.log(...args),
})
 
connection.run('pwd')
 
// Will output:
// Running "pwd" on host "localhost".
// @localhost /my/directory

connection.run(command, [options])

Run a command on the remote server, you can specify custom childProcess.exec options.

Parameters:

@param {string} command Command to run
@param {object} [options] Options
@param {boolean} [options.tty] Force a TTY allocation.
@returns {ExecResult}
@throws {ExecError}

// Run "ls" command on a remote server
connection.run('ls').then(res => {
  console.log(res.stdout) // file1 file2 file3
})

connection.copyToRemote(src, dest, [options])

Copy a file or a directory from local to a remote server, you can specify custom childProcess.exec options. It uses rsync under the hood.

Parameters:

* @param {string} src Source
* @param {string} dest Destination
* @param {object} [options] Options
* @param {string[]} [options.ignores] Specify a list of files to ignore.
* @param {string[]|string} [options.rsync] Specify a set of rsync arguments.
* @returns {ExecResult}
* @throws {ExecError}

// Copy a local file to a remote file using Rsync
connection.copyToRemote('./localfile', '/remote-file').then(() => {
  console.log('File copied!')
})

connection.copyFromRemote(src, dest, [options])

Copy a file or a directory from a remote server to local, you can specify custom childProcess.exec options. It uses rsync under the hood.

Parameters:

* @param {string} src Source
* @param {string} dest Destination
* @param {object} [options] Options
* @param {string[]} [options.ignores] Specify a list of files to ignore.
* @param {string[]|string} [options.rsync] Specify a set of rsync arguments.
* @returns {ExecResult}
* @throws {ExecError}

// Copy a remote file to a local file using Rsync
connection.copyFromRemote('/remote-file', './local-file').then(() => {
  console.log('File copied!')
})

new ConnectionPool(connections, [options])

Create a new pool of connections and custom options for all connections. You can use either short syntax or connections to create a pool.

import { Connection, ConnectionPool } from 'ssh-pool'
 
// Use shorthand.
const pool = new ConnectionPool(['server1', 'server2'])
 
// Use previously created connections.
const connection1 = new Connection({ remote: 'server1' })
const connection2 = new Connection({ remote: 'server2' })
const pool = new ConnectionPool([connection1, connection2])

Connection Pool accepts exactly the same methods as Connection. It runs commands in parallel on each server defined in the pool. You get an array of results.

isRsyncSupported()

Test if rsync is supported on the local machine.

import { isRsyncSupported } from 'ssh-pool'
 
isRsyncSupported().then(supported => {
  if (supported) {
    console.log('Rsync is supported!')
  } else {
    console.log('Rsync is not supported!')
  }
})

exec(cmd, options, childModifier)

Execute a command and return an object containing { child, stdout, stderr }.

import { exec } from 'ssh-pool'
 
exec('echo "hello"')
  .then(({ stdout }) => console.log(stdout))
  .catch(({ stderr, stdout }) => console.error(stderr))

License

MIT