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configuration.coffee

The Configuration class encapsulates various options for a Pow daemon (port numbers, directories, etc.). It's also responsible for creating Logger instances and mapping hostnames to application root paths.

 
fs                = require "fs"
path              = require "path"
async             = require "async"
Logger            = require "./logger"
{mkdirp}          = require "./util"
{sourceScriptEnv} = require "./util"
{getUserEnv}      = require "./util"

module.exports = class Configuration

The user configuration file, ~/.powconfig, is evaluated on boot. You can configure options such as the top-level domain, number of workers, the worker idle timeout, and listening ports.

export POW_DOMAINS=dev,test
export POW_WORKERS=3

See the Configuration constructor for a complete list of environment options.

 
  @userConfigurationPath: path.join process.env.HOME, ".powconfig"

Evaluates the user configuration script and calls the callback with the environment variables if the config file exists. Any script errors are passed along in the first argument. (No error occurs if the file does not exist.)

 
  @loadUserConfigurationEnvironment: (callback) ->
    getUserEnv (err, env) =>
      if err
        callback err
      else
        path.exists p = @userConfigurationPath, (exists) ->
          if exists
            sourceScriptEnv p, env, callback
          else
            callback null, env

Creates a Configuration object after evaluating the user configuration file. Any environment variables in ~/.powconfig affect the process environment and will be copied to spawned subprocesses.

 
  @getUserConfiguration: (callback) ->
    @loadUserConfigurationEnvironment (err, env) ->
      if err
        callback err
      else
        callback null, new Configuration env

A list of option names accessible on Configuration instances.

 
  @optionNames: [
    "bin", "dstPort", "httpPort", "dnsPort", "timeout", "workers",
    "domains", "extDomains", "hostRoot", "logRoot", "rvmPath"
  ]

Pass in any environment variables you'd like to override when creating a Configuration instance.

 
  constructor: (env = process.env) ->
    @loggers = {}
    @initialize env

Valid environment variables and their defaults:

 
  initialize: (@env) ->

POW_BIN: the path to the pow binary. (This should be correctly configured for you.)

 
    @bin        = env.POW_BIN         ? path.join __dirname, "../bin/pow"

POW_DST_PORT: the public port Pow expects to be forwarded or otherwise proxied for incoming HTTP requests. Defaults to 80.

 
    @dstPort    = env.POW_DST_PORT    ? 80

POW_HTTP_PORT: the TCP port Pow opens for accepting incoming HTTP requests. Defaults to 20559.

 
    @httpPort   = env.POW_HTTP_PORT   ? 20559

POW_DNS_PORT: the UDP port Pow listens on for incoming DNS queries. Defaults to 20560.

 
    @dnsPort    = env.POW_DNS_PORT    ? 20560

POW_TIMEOUT: how long (in seconds) to leave inactive Rack applications running before they're killed. Defaults to 15 minutes (900 seconds).

 
    @timeout    = env.POW_TIMEOUT     ? 15 * 60

POW_WORKERS: the maximum number of worker processes to spawn for any given application. Defaults to 2.

 
    @workers    = env.POW_WORKERS     ? 2

POW_DOMAINS: the top-level domains for which Pow will respond to DNS A queries with 127.0.0.1. Defaults to dev. If you configure this in your ~/.powconfig you will need to re-run sudo pow --install-system to make /etc/resolver aware of the new TLDs.

 
    @domains    = env.POW_DOMAINS     ? env.POW_DOMAIN ? "dev"

POW_EXT_DOMAINS: additional top-level domains for which Pow will serve HTTP requests (but not DNS requests -- hence the "ext").

 
    @extDomains = env.POW_EXT_DOMAINS ? []

Allow for comma-separated domain lists, e.g. POW_DOMAINS=dev,test

 
    @domains    = @domains.split?(",")    ? @domains
    @extDomains = @extDomains.split?(",") ? @extDomains
    @allDomains = @domains.concat @extDomains

Support *.xip.io top-level domains.

 
    @allDomains.push /\d+\.\d+\.\d+\.\d+\.xip\.io$/, /[0-9a-z]{1,7}\.xip\.io$/

Runtime support files live in ~/Library/Application Support/Pow.

 
    @supportRoot = libraryPath "Application Support", "Pow"

POW_HOST_ROOT: path to the directory containing symlinks to applications that will be served by Pow. Defaults to ~/Library/Application Support/Pow/Hosts.

 
    @hostRoot   = env.POW_HOST_ROOT   ? path.join @supportRoot, "Hosts"

POW_LOG_ROOT: path to the directory that Pow will use to store its log files. Defaults to ~/Library/Logs/Pow.

 
    @logRoot    = env.POW_LOG_ROOT    ? libraryPath "Logs", "Pow"

POW_RVM_PATH (deprecated): path to the rvm initialization script. Defaults to ~/.rvm/scripts/rvm.

 
    @rvmPath    = env.POW_RVM_PATH    ? path.join process.env.HOME, ".rvm/scripts/rvm"

Precompile regular expressions for matching domain names to be served by the DNS server and hosts to be served by the HTTP server.

 
    @dnsDomainPattern  = compilePattern @domains
    @httpDomainPattern = compilePattern @allDomains

Gets an object of the Configuration instance's options that can be passed to JSON.stringify.

 
  toJSON: ->
    result = {}
    result[key] = @[key] for key in @constructor.optionNames
    result

Retrieve a Logger instance with the given name.

 
  getLogger: (name) ->
    @loggers[name] ||= new Logger path.join @logRoot, name + ".log"

Globally disable or enable RVM deprecation notices by touching or removing the ~/Library/Application Support/Pow/.disableRvmDeprecationNotices file.

 
  disableRvmDeprecationNotices: ->
    fs.writeFile path.join(@supportRoot, ".disableRvmDeprecationNotices"), ""

  enableRvmDeprecationNotices: ->
    fs.unlink path.join @supportRoot, ".disableRvmDeprecationNotices"

Search hostRoot for files, symlinks or directories matching the domain specified by host. If a match is found, the matching domain name and its configuration are passed as second and third arguments to callback. The configuration will either have a root or a port property. If no match is found, callback is called without any arguments. If an error is raised, callback is called with the error as its first argument.

 
  findHostConfiguration: (host = "", callback) ->
    @gatherHostConfigurations (err, hosts) =>
      return callback err if err
      for domain in @allDomains
        for file in getFilenamesForHost host, domain
          if config = hosts[file]
            return callback null, domain, config

      if config = hosts["default"]
        return callback null, @allDomains[0], config

      callback null

Asynchronously build a mapping of entries in hostRoot to application root paths and proxy ports. For each symlink, store the symlink's name and the real path of the application it points to. For each directory, store the directory's name and its full path. For each file that contains a port number, store the file's name and the port. The mapping is passed as an object to the second argument of callback. If an error is raised, callback is called with the error as its first argument.

The mapping object will look something like this:

{
  "basecamp":  { "root": "/Volumes/37signals/basecamp" },
  "launchpad": { "root": "/Volumes/37signals/launchpad" },
  "37img":     { "root": "/Volumes/37signals/portfolio" },
  "couchdb":   { "url":  "http://localhost:5984" }
}

  gatherHostConfigurations: (callback) ->
    hosts = {}
    mkdirp @hostRoot, (err) =>
      return callback err if err
      fs.readdir @hostRoot, (err, files) =>
        return callback err if err
        async.forEach files, (file, next) =>
          root = path.join @hostRoot, file
          name = file.toLowerCase()
          rstat root, (err, stats, path) ->
            if stats?.isDirectory()
              hosts[name] = root: path
              next()
            else if stats?.isFile()
              fs.readFile path, 'utf-8', (err, data) ->
                return next() if err
                data = data.trim()
                if data.length < 10 and not isNaN(parseInt(data))
                  hosts[name] = {url: "http://localhost:#{parseInt(data)}"}
                else if data.match("https?://")
                  hosts[name] = {url: data}
                next()
            else
              next()
        , (err) ->
          callback err, hosts

Convenience wrapper for constructing paths to subdirectories of ~/Library.

 
libraryPath = (args...) ->
  path.join process.env.HOME, "Library", args...

Strip a trailing domain from the given host, then generate a sorted array of possible entry names for finding which application should serve the host. For example, a host of asset0.37s.basecamp.dev will produce ["asset0.37s.basecamp", "37s.basecamp", "basecamp"], and basecamp.dev will produce ["basecamp"].

 
getFilenamesForHost = (host, domain) ->
  host = host.toLowerCase()
  domain = host.match(domain)?[0] ? "" if domain.test?

  if host.slice(-domain.length - 1) is ".#{domain}"
    parts  = host.slice(0, -domain.length - 1).split "."
    length = parts.length
    for i in [0...length]
      parts.slice(i, length).join "."
  else
    []

Similar to fs.stat, but passes the realpath of the file as the third argument to the callback.

 
rstat = (path, callback) ->
  fs.lstat path, (err, stats) ->
    if err
      callback err
    else if stats?.isSymbolicLink()
      fs.realpath path, (err, realpath) ->
        if err then callback err
        else rstat realpath, callback
    else
      callback err, stats, path

Helper function for compiling a list of top-level domains into a regular expression for matching purposes.

 
compilePattern = (domains) ->
  /// ( (^|\.) (#{domains.join("|")}) ) \.? $ ///i