thelinuxlich-flightplan

Library for streamlining application deployment or systems administration tasks

Flightplan ✈

Run a sequence of commands against local and remote hosts.

Flightplan is a node.js library for streamlining application deployment or systems administration tasks, similar to Python's Fabric.

# 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 <destination> [--plan flightplan.(js|coffee)]

By default, the fly command will look for flightplan.js or flightplan.coffee.

If you do not install the Flightplan module locally to your project (i.e. to support non-javascript projects) then make sure the global node_modules is in your Node.js path. For example:

$ export NODE_PATH=/usr/local/lib/node_modules
$ fly <destination>
// flightplan.js 
var Flightplan = require('flightplan');
 
var tmpDir = 'pstadler-sh-' + new Date().getTime();
 
var plan = new Flightplan();
 
// configuration 
plan.briefing({
  debug: false,
  destinations: {
    'staging': {
      host: 'staging.pstadler.sh',
      username: 'pstadler',
      agent: process.env.SSH_AUTH_SOCK
    },
    'production': [
      {
        host: 'www1.pstadler.sh',
        username: 'pstadler',
        agent: process.env.SSH_AUTH_SOCK
      },
      {
        host: 'www2.pstadler.sh',
        username: 'pstadler',
        agent: process.env.SSH_AUTH_SOCK
      }
    ]
  }
});
 
// 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 destination's hosts 
  local.transfer(filesToCopy, '/tmp/' + tmpDir);
});
 
// run commands on remote hosts (destinations) 
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 + ' ~/pstadler-sh', {user: 'www'});
  remote.sudo('pm2 reload pstadler-sh', {user: 'www'});
});
 
// run more commands on localhost afterwards 
plan.local(function(local) { /* ... */ });
// ...or on remote hosts 
plan.remote(function(remote) { /* ... */ });
 
// executed if flightplan succeeded 
plan.success(function() { /* ... */ });
 
// executed if flightplan failed 
plan.disaster(function() { /* ... */ });
 
// always executed after flightplan finished 
plan.debriefing(function() { /* ... */ });

Documentation

A flightplan is a set of subsequent flights to be executed on one or more hosts. The constructor doesn't take any arguments. The configuration is handled with the briefing() method.

var plan = new Flightplan();

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

Commands in local flights are executed on the localhost.

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

Commands in remote flights are executed in parallel against remote hosts defined during the briefing.

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) {});
 
// ... 

Configure the flightplan's destinations with briefing(). Without a proper briefing you can't do remote flights which require at least one destination. Each destination consists of one ore 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.

plan.briefing({
  destinations: {
    // run with `fly staging` 
    'staging': {
      // see: https://github.com/mscdex/ssh2#connection-methods 
      host: 'staging.pstadler.sh',
      username: 'pstadler',
      agent: process.env.SSH_AUTH_SOCK
    },
    // run with `fly production` 
    'production': [
      {
        host: 'www1.pstadler.sh',
        username: 'pstadler',
        agent: process.env.SSH_AUTH_SOCK
      },
      {
        host: 'www2.pstadler.sh',
        username: 'pstadler',
        agent: process.env.SSH_AUTH_SOCK
      },
    ]
  }
});

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

fly production --username=admin

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.');
});

Calling this method registers a remote flight. Remote flights are executed on the current destination's remote hosts defined with briefing(). When fn gets called a Transport object is passed with the first argument.

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

fn() is called after the flightplan (and therefore all flights) succeeded.

fn() is called after the flightplan was aborted.

fn() is called at the very end of the flightplan's execution.

Whether the flightplan is aborted or not.

Calling this method will abort the flightplan and prevent any further flights from being executed.

plan.abort();

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 ShellTransport object for local flights, or an SSHTransport for remote flights. Both transports expose the same set of methods as described in this section.

plan.local(function(local) {
  local.echo('ShellTransport.echo() called');
});
 
plan.remote(function(remote) {
  remote.echo('SSHTransport.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.

Flightplan provides information during flights with the target properties:

plan.remote(function(transport) { // applies to local flights as well 
  // Flightplan specific information 
  console.log(plan.target.destination); // 'production' 
  console.log(plan.target.hosts); // [{ host: 'www1.pstadler.sh', port: 22 }, ...] 
 
  // Flight specific information 
  console.log(transport.target); // { host: 'www1.pstadler.sh', port: 22 } 
});

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 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().

Each command returns an object containing code, stdout andstderr:

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

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

Copy a list of files to the current destination'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');

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 briefing() unless fly is called with the -u|--username option. In this case the latter will be used. If debugging is enabled (either with briefing() or with fly --debug), rsync is executed in verbose mode (-v).

Prompt for user input.

var input = transport.prompt('Are you sure you want to continue? [yes]');
if(input.indexOf('yes') === -1) {
  transport.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 destination 
if(plan.target.destination === 'production') {
  var input = transport.prompt('Ready for deploying to production? [yes]');
  if(input.indexOf('yes') === -1) {
    transport.abort('user canceled flight');
  }
}

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');

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(errresponse) {
      done(err || 'sent!');
    });
});
console.log(result); // 'sent!' 

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 
});

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 

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 

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');

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 

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');

Manually abort the current flight 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.

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