Gurpartap/cognizant

#!/usr/bin/env ruby

# Set the process name.
$0 = File.basename(__FILE__)

# Flush standard output/error immediately.
$stdout.sync = true
$stderr.sync = true

begin
  require "optparse"
  require "cognizant/version"
  require "cognizant/controller"
  require "cognizant/util/transform_hash_keys"

  options = {}

  OptionParser.new do |opts|
    opts.banner = <<-EOF
NAME
    cognizantd - system utility daemon to supervise your processes

SYNOPSIS:
    cognizantd [global options] [config file | -]

VERSION
    #{Cognizant::VERSION}

GLOBAL OPTIONS:
    EOF

    opts.on("--[no-]daemonize", "Whether or not to daemonize cognizantd into background.") do |value|
      options[:daemonize] = value
    end

    opts.on("--sockfile FILE", String, "The socket lock file of the command server.") do |value|
      options[:pidfile] = value
    end

    opts.on("--pidfile FILE", String, "The pid (process identifier) lock file for the daemon.") do |value|
      options[:pidfile] = value
    end

    opts.on("--syslog", String, "Log the daemon's operational information into syslog.") do |_|
      options[:syslog] = true
    end

    opts.on("--logfile FILE", String, "Log the daemon's operational information into a file.") do |value|
      options[:logfile] = value
    end

    opts.on("--loglevel LEVEL", String, "The level of information to log.") do |value|
      options[:loglevel] = value
    end

    opts.on("-t", "--trace", "Turn on tracing, enable full backtrace.") do
      options[:trace] = true
    end

    opts.on("-v", "--version", "Print the version number and exit.") do
      require "cognizant/version"
      $stdout.puts Cognizant::VERSION
      exit(0)
    end
  end.parse!

  config = {}
  config_file = ARGV.shift

  if config_file == "-"
    config = YAML.load(ARGF.read)

  elsif config_file.to_s.size > 0
    if File.exists?(config_file)
      config = YAML.load_file(config_file)
    elsif File.exists?(default_config_file = "/etc/cognizant/cognizantd.yml")
      config = YAML.load_file(default_config_file)
    end
  end

  config.deep_symbolize_keys!
  config = config.merge(options)
  trace = config[:trace]

  Cognizant::Controller.start_daemon(config)
rescue => exception
  if exception.instance_of?(SystemExit)
    raise
  else
    $stderr.puts "ERROR  While executing #{$0} ... (#{exception.class})"
    $stderr.puts "    #{exception.message}\n\n"

    if trace
      $stderr.puts exception.backtrace.join("\n")
      $stderr.puts "\n(See usage by running #{$0} with --help)"
    else
      $stderr.puts "(See full trace by running #{$0} with --trace)"
    end
    exit(1)
  end
end