@ddn/flightplan

Flightplan

Run sequences of shell commands against local and remote hosts.

Flightplan is a node.js library for streamlining application deployment or systems administration tasks.

A complete list of changes can be found in the Changelog.

Looking for help / maintainers: See #162.

Installation & Usage

# install the cli tool
$ npm install -g flightplan

# use it in your project
$ npm install flightplan --save-dev

# run a flightplan (`fly --help` for more information)
$ fly [task:]<target> [--flightplan flightplan.(js|coffee)]

By default, the fly command will try to load flightplan.js or flightplan.coffee.

Sample flightplan.js

// flightplan.js
var plan = require('flightplan');

// configuration
plan.target('staging', {
  host: 'staging.example.com',
  username: 'pstadler',
  agent: process.env.SSH_AUTH_SOCK
});

plan.target('production', [
  {
    host: 'www1.example.com',
    username: 'pstadler',
    agent: process.env.SSH_AUTH_SOCK
  },
  {
    host: 'www2.example.com',
    username: 'pstadler',
    agent: process.env.SSH_AUTH_SOCK
  }
]);

var tmpDir = 'example-com-' + new Date().getTime();

// run commands on localhost
plan.local(function(local) {
  local.log('Run build');
  local.exec('gulp build');

  local.log('Copy files to remote hosts');
  var filesToCopy = local.exec('git ls-files', {silent: true});
  // rsync files to all the target's remote hosts
  local.transfer(filesToCopy, '/tmp/' + tmpDir);
});

// run commands on the target's remote hosts
plan.remote(function(remote) {
  remote.log('Move folder to web root');
  remote.sudo('cp -R /tmp/' + tmpDir + ' ~', {user: 'www'});
  remote.rm('-rf /tmp/' + tmpDir);

  remote.log('Install dependencies');
  remote.sudo('npm --production --prefix ~/' + tmpDir
                            + ' install ~/' + tmpDir, {user: 'www'});

  remote.log('Reload application');
  remote.sudo('ln -snf ~/' + tmpDir + ' ~/example-com', {user: 'www'});
  remote.sudo('pm2 reload example-com', {user: 'www'});
});

// run more commands on localhost afterwards
plan.local(function(local) { /* ... */ });
// ...or on remote hosts
plan.remote(function(remote) { /* ... */ });

Documentation

Flightplan

A flightplan is a set of subsequent flights to be executed on one or more hosts. Configuration is handled with the target() method.

var plan = require('flightplan');

Flights

A flight is a set of commands to be executed on one or more hosts. There are two types of flights:

Local flights

Commands in local flights are executed on the localhost.

plan.local(function(transport) {
  transport.hostname(); // prints the hostname of localhost
});

Remote flights

Commands in remote flights are executed in parallel against remote hosts.

plan.remote(function(transport) {
  transport.hostname(); // prints the hostname(s) of the remote host(s)
});

You can define multiple flights of each type. They will be executed in the order of their definition. If a previous flight failed, all subsequent flights won't get executed. For more information about what it means for a flight to fail, see the section about Transport.

// executed first
plan.local(function(transport) {});

// executed if first flight succeeded
plan.remote(function(transport) {});

// executed if second flight succeeded
plan.local(function(transport) {});

// ...

Tasks

Flightplan supports optional tasks to run a subset of flights.

// fly deploy:<target>
plan.local('deploy', function(transport) {});

// fly build:<target>
plan.local('build', function(transport) {});

// fly deploy:<target> or...
// fly build:<target>
plan.local(['deploy', 'build'], function(transport) {});
plan.remote(['deploy', 'build'], function(transport) {});

If no task is specified it's implicitly set to "default". Therefore, fly <target> is the same as fly default:<target>.

// fly <target>
plan.local(function(transport) {});
// is the same as...
plan.local('default', function(transport) {});
// "default" + other tasks:
plan.remote(['default', 'deploy', 'build'], function(transport) {});

flightplan.target(name, hosts[, options]) → this

Configure the flightplan's targets with target(). Without a proper setup you can't do remote flights which require at least one remote host. Each target consists of one or more hosts.

Values in the hosts section are passed directly to the connect() method of mscdex/ssh2 with one exception: privateKey needs to be passed as a string containing the path to the keyfile instead of the key itself.

// run with `fly staging`
plan.target('staging', {
  // see: https://github.com/mscdex/ssh2#connection-methods
  host: 'staging.example.com',
  username: 'pstadler',
  agent: process.env.SSH_AUTH_SOCK
});

// run with `fly production`
plan.target('production', [
  {
    host: 'www1.example.com',
    username: 'pstadler',
    agent: process.env.SSH_AUTH_SOCK
  },
  {
    host: 'www2.example.com',
    username: 'pstadler',
    agent: process.env.SSH_AUTH_SOCK
  }
]);

// run with `fly dynamic-hosts`
plan.target('dynamic-hosts', function(done, runtime) {
  var AWS = require('aws-sdk');
  AWS.config.update({accessKeyId: '...', secretAccessKey: '...'});
  var ec2 = new AWS.EC2();
  var params = {Filters: [{Name: 'instance-state-name', Values: ['running']}]};
  ec2.describeInstances(params, function(err, response) {
    if(err) {
      return done(err);
    }
    var hosts = [];
    response.data.Reservations.forEach(function(reservation) {
      reservation.Instances.forEach(function(instance) {
        hosts.push({
          host: instance.PublicIpAddress,
          username: 'pstadler',
          agent: process.env.SSH_AUTH_SOCK
        });
      });
    });
    done(hosts);
  });
});

Usually flightplan will abort when a host is not reachable or authentication fails. This can be prevented by setting a property failsafe to true on any of the host configurations:

plan.target('production', [
  {
    host: 'www1.example.com',
    username: 'pstadler',
    agent: process.env.SSH_AUTH_SOCK
  },
  {
    host: 'www2.example.com',
    username: 'pstadler',
    agent: process.env.SSH_AUTH_SOCK,
    failsafe: true // continue flightplan even if connection to www2 fails
  }
]);

You can override the username value of hosts by calling fly with the -u|--username option:

fly production --username=admin

Configuring remote hosts during runtime (e.g. using AWS/EC2)

Instead of having a static hosts configuration for a target you can configure it on the fly by passing a function fn(done) as the second argument to target().

This function is executed at the very beginning. Whatever is passed to done() will be used for connecting to remote hosts. This can either be an object or an array of objects depending on if you want to connect to one or multiple hosts. Passing an Error object will immediately abort the current flightplan.

plan.target('dynamic-hosts', function(done, runtime) {
  var AWS = require('aws-sdk');
  AWS.config.update({accessKeyId: '...', secretAccessKey: '...'});
  var ec2 = new AWS.EC2();
  var params = {Filters: [{Name: 'instance-state-name', Values: ['running']}]};
  ec2.describeInstances(params, function(err, response) {
    if(err) {
      return done(err);
    }
    var hosts = [];
    response.data.Reservations.forEach(function(reservation) {
      reservation.Instances.forEach(function(instance) {
        hosts.push({
          host: instance.PublicIpAddress,
          username: 'pstadler',
          agent: process.env.SSH_AUTH_SOCK
        });
      });
    });
    done(hosts);
  });
});

Defining and using properties depending on the target

target() takes an optional third argument to define properties used by this target. Values defined in this way can be accessed during runtime.

plan.target('staging', {...}, {
  webRoot: '/usr/local/www',
  sudoUser: 'www'
});

plan.target('production', {...}, {
  webRoot: '/home/node',
  sudoUser: 'node'
});

plan.remote(function(remote) {
  var webRoot = plan.runtime.options.webRoot;   // fly staging -> '/usr/local/www'
  var sudoUser = plan.runtime.options.sudoUser; // fly staging -> 'www'
  remote.sudo('ls -al ' + webRoot, {user: sudoUser});
});

Properties can be set and overwritten by passing them as named options to the fly command.

$ fly staging --sudoUser=foo
# plan.runtime.options.sudoUser -> 'foo'

flightplan.local([tasks, ]fn) → this

Calling this method registers a local flight. Local flights are executed on your localhost. When fn gets called a Transport object is passed with the first argument.

plan.local(function(local) {
  local.echo('hello from your localhost.');
});

An optional first parameter of type Array or String can be passed for defining the flight's task(s).

flightplan.remote([tasks, ]fn) → this

Register a remote flight. Remote flights are executed on the current target's remote hosts defined with target(). When fn gets called a Transport object is passed with the first argument.

plan.remote(function(remote) {
  remote.echo('hello from the remote host.');
});

An optional first parameter of type Array or String can be passed for defining the flight's task(s).

flightplan.abort([message])

Manually abort the current flightplan and prevent any further commands and flights from being executed. An optional message can be passed which is displayed after the flight has been aborted.

plan.abort('Severe turbulences over the atlantic ocean!');

Transport

A transport is the interface you use during flights. Basically they offer you a set of methods to execute a chain of commands. Depending on the type of flight, this is either a Shell object for local flights, or an SSH for remote flights. Both transports expose the same set of methods as described in this section.

plan.local(function(local) {
  local.echo('Shell.echo() called');
});

plan.remote(function(remote) {
  remote.echo('SSH.echo() called');
});

We call the Transport object transport in the following section to avoid confusion. However, do yourself a favor and use local for local, and remote for remote flights.

Accessing runtime information

Flightplan provides information during flights with the runtime properties:

plan.remote(function(transport) { // applies to local flights as well
  // Flightplan specific information
  console.log(plan.runtime.task);    // 'default'
  console.log(plan.runtime.target);  // 'production'
  console.log(plan.runtime.hosts);   // [{ host: 'www1.example.com', port: 22 }, ...]
  console.log(plan.runtime.options); // { debug: true, ... }

  // Flight specific information
  console.log(transport.runtime); // { host: 'www1.example.com', port: 22 }
});

transport.exec(command[, options]) → code: int, stdout: String, stderr: String

To execute a command you have the choice between using exec() or one of the handy wrappers for often used commands: transport.exec('ls -al') is the same as transport.ls('-al'). If a command returns a non-zero exit code, the flightplan will be aborted and all subsequent commands and flights won't get executed.

Options

Options can be passed as a second argument. If failsafe: true is passed, the command is allowed to fail (i.e. exiting with a non-zero exit code), whereas silent: true will simply suppress its output.

// output of `ls -al` is suppressed
transport.ls('-al', {silent: true});

// flightplan continues even if command fails with exit code `1`
transport.ls('-al foo', {failsafe: true}); // ls: foo: No such file or directory

// both options together
transport.ls('-al foo', {silent: true, failsafe: true});

To apply these options to multiple commands check out the docs of transport.silent() and transport.failsafe().

Return value

Each command returns an object containing code, stdout andstderr:

var result = transport.echo('Hello world');
console.log(result); // { code: 0, stdout: 'Hello world\n', stderr: null }

Advanced options

Flightplan uses child_process#exec() for executing local commands and mscdex/ssh2#exec() for remote commands. Options passed with exec will be forwarded to either of these functions.

// increase maxBuffer for child_process#exec()
local.ls('-al', {exec: {maxBuffer: 2000*1024}});

// enable pty for mscdex/ssh2#exec()
remote.ls('-al', {exec: {pty: true}});

transport.sudo(command[, options]) → code: int, stdout: String, stderr: String

Execute a command as another user with sudo(). It has the same signature as exec(). Per default, the user under which the command will be executed is "root". This can be changed by passing user: "name" with the second argument:

// will run: echo 'echo Hello world' | sudo -u root -i bash
transport.sudo('echo Hello world');

// will run echo 'echo Hello world' | sudo -u www -i bash
transport.sudo('echo Hello world', {user: 'www'});

// further options passed (see `exec()`)
transport.sudo('echo Hello world', {user: 'www', silent: true, failsafe: true});

Flightplan's sudo() requires a certain setup on your host. In order to make things work on a typical Ubuntu installation, follow these rules:

# Scenario:
# 'pstadler' is the user for connecting to the host and 'www' is the user
# under which you want to execute commands with sudo.

# 1. 'pstadler' has to be in the sudo group:
$ groups pstadler
pstadler : pstadler sudo

# 2. 'pstadler' needs to be able to run sudo -u 'www' without a password.
# In order to do this, add the following line to /etc/sudoers:
pstadler ALL=(www) NOPASSWD: ALL

# 3. user 'www' needs to have a login shell (e.g. bash, sh, zsh, ...)
$ cat /etc/passwd | grep www
www:x:1002:1002::/home/www:/bin/bash   # GOOD
www:x:1002:1002::/home/www:/bin/false  # BAD

transport.transfer(files, remoteDir[, options]) → [results]

Copy a list of files to the current target's remote host(s) using rsync with the SSH protocol. File transfers are executed in parallel. After finishing all transfers, an array containing results from transport.exec() is returned. This method is only available on local flights.

var files = ['path/to/file1', 'path/to/file2'];
local.transfer(files, '/tmp/foo');

Files argument

To make things more comfortable, the files argument doesn't have to be passed as an array. Results from previous commands and zero-terminated strings are handled as well:

// use result from a previous command
var files = local.git('ls-files', {silent: true}); // get list of files under version control
local.transfer(files, '/tmp/foo');

// use zero-terminated result from a previous command
var files = local.exec('(git ls-files -z;find node_modules -type f -print0)', {silent: true});
local.transfer(files, '/tmp/foo');

// use results from multiple commands
var result1 = local.git('ls-files', {silent: true}).stdout.split('\n');
var result2 = local.find('node_modules -type f', {silent: true}).stdout.split('\n');
var files = result1.concat(result2);
files.push('path/to/another/file');
local.transfer(files, '/tmp/foo');

transfer() will use the current host's username defined with target() unless fly is called with the -u|--username option. In this case the latter will be used. If debugging is enabled (either with target() or with fly --debug), rsync is executed in verbose mode (-vv).

transport.prompt(message[, options]) → input

Prompt for user input.

var input = transport.prompt('Are you sure you want to continue? [yes]');
if(input.indexOf('yes') === -1) {
  plan.abort('User canceled flight');
}

// prompt for password (with UNIX-style hidden input)
var password = transport.prompt('Enter your password:', { hidden: true });

// prompt when deploying to a specific target
if(plan.runtime.target === 'production') {
  var input = transport.prompt('Ready for deploying to production? [yes]');
  if(input.indexOf('yes') === -1) {
    plan.abort('User canceled flight');
  }
}

transport.waitFor(fn(done)) → {} mixed

Execute a function and return after the callback done is called. This is used for running asynchronous functions in a synchronous way.

The callback takes an optional argument which is then returned by waitFor().

var result = transport.waitFor(function(done) {
  require('node-notifier').notify({
      message: 'Hello World'
    }, function(err, response) {
      done(err || 'sent!');
    });
});
console.log(result); // 'sent!'

transport.with(command|options[, options], fn)

Execute commands with a certain context.

transport.with('cd /tmp', function() {
  transport.ls('-al'); // 'cd /tmp && ls -al'
});

transport.with({silent: true, failsafe: true}, function() {
  transport.ls('-al'); // output suppressed, fail safely
});

transport.with('cd /tmp', {silent: true}, function() {
  transport.ls('-al'); // 'cd /tmp && ls -al', output suppressed
});

transport.silent()

When calling silent() all subsequent commands are executed without printing their output to stdout until verbose() is called.

transport.ls(); // output will be printed to stdout
transport.silent();
transport.ls(); // output won't be printed to stdout

transport.verbose()

Calling verbose() reverts the behavior introduced with silent(). Output of commands will be printed to stdout.

transport.silent();
transport.ls(); // output won't be printed to stdout
transport.verbose();
transport.ls(); // output will be printed to stdout

transport.failsafe()

When calling failsafe(), all subsequent commands are allowed to fail until unsafe() is called. In other words, the flight will continue even if the return code of the command is not 0. This is helpful if either you expect a command to fail or their nature is to return a non-zero exit code.

transport.failsafe();
transport.ls('foo'); // ls: foo: No such file or directory
transport.log('Previous command failed, but flight was not aborted');

transport.unsafe()

Calling unsafe() reverts the behavior introduced with failsafe(). The flight will be aborted if a subsequent command fails (i.e. returns a non-zero exit code). This is the default behavior.

transport.failsafe();
transport.ls('foo'); // ls: foo: No such file or directory
transport.log('Previous command failed, but flight was not aborted');
transport.unsafe();
transport.ls('foo'); // ls: foo: No such file or directory
// flight aborted

transport.log(message)

Print a message to stdout. Flightplan takes care that the message is formatted correctly within the current context.

transport.log('Copying files to remote hosts');

transport.debug(message)

Print a debug message to stdout if debug mode is enabled. Flightplan takes care that the message is formatted correctly within the current context.

transport.debug('Copying files to remote hosts');