provision

#!/usr/bin/env ruby

require "open3"
require "logger"
require "tempfile"

LOG_LEVEL = ENV.has_key?("LOG_LEVEL") ? ENV["LOG_LEVEL"].upcase : "DEBUG"
ROOT = File.dirname(__FILE__)

Console = Logger.new(STDOUT)
Console.level = Logger.const_get(LOG_LEVEL)
Console.formatter = proc do |level, datetime, progname, msg|
  msg.chomp + "\n"
end

SCRIPT_ENV = {'DEBIAN_FRONTEND' => 'noninteractive'}.merge(ENV)

module CommandLineHelper
  def self.help
    <<-EOF
Provision a radiodan application device.
#{__FILE__} [steps]
Valid Steps: #{Steps.valid_steps.join(", ")}.
    EOF
  end

  def self.invalid
    <<-EOF
Supplied steps are invalid.
    EOF
  end
end

module Steps
  def self.valid?(steps)
    sorted_steps = steps.sort
    (valid_steps & sorted_steps) == sorted_steps
  end

  def self.execute(steps)
    @install_steps = []
    @config_steps  = []
    @failed_steps  = []

    if steps.include?("all")
      enqueue_all
    else
      steps.each{|s| enqueue(s)}
    end

    execute!

    Console.info "#{@install_steps.length} steps selected, " +
        "#{@failed_steps.length} failed."

    unless @failed_steps.empty?
      Console.error "Failed steps: #{@failed_steps.join(", ")}"
    end
  end

  def self.valid_steps
    @valid_steps ||= (["all"] +
      Dir.entries(ROOT+"/steps").reject{|x| x[0] == "." || x[0] == "_" }).sort
  end

  def self.enqueue_all
    enqueue("_pre-install")
    valid_steps[1..-1].each{|s| enqueue(s)}
    enqueue("_post-install")
  end

  def self.enqueue(step_name)
    @install_steps << step_name
    @config_steps  << step_name
  end

  def self.execute!
    @install_steps.each_with_index do |step, index|
      script = parse_script(step, "install")

      unless script
        Console.warn "No install step for #{step}"
        next
      end

      Console.info "Installing #{step} (#{index+1}/#{@install_steps.count})"
      Open3.popen2e(SCRIPT_ENV, "/bin/sh", script) do |stdin, response, status|
        until (s = response.gets).nil? do
          Console.debug "#{step}: #{s}"
        end

        unless status.value.success?
          @failed_steps << step
          Console.error "Failed #{step} install."
        end
      end
    end

    @config_steps.each_with_index do |step, index|
      if @failed_steps.include?(step)
        Console.debug "Skipped #{step} config, due to presence in failed steps"
        next
      end

      script = parse_script(step, "configure")

      unless script
        Console.debug "No config step for #{step}"
        next
      end

      Console.info "Configuring #{step} (#{index+1}/#{@config_steps.count})"
      Open3.popen2e(SCRIPT_ENV, "/bin/sh", script) do |stdin, response, status|
        until (s = response.gets).nil? do
          Console.debug "#{step}: #{s}"
        end

        unless status.value.success?
          @failed_steps << step
          Console.error "Failed #{step} configure."
        end
      end
    end
  end

  def self.parse_script(step, script_name)
    dir = File.join(ROOT, "steps", step)
    conf_dir = File.join(dir, "files")
    file = File.join(dir, "#{script_name}.sh")

    if File.exist?(file)
      # Add set -e so script fails on first error
      src = "set -e \n" + File.read(file)
      parsed = src.gsub "${RADIODAN_CONF}", conf_dir

      tmp = Tempfile.new("provision_script_#{script_name}_#{step}")
      tmp.write parsed
      tmp.close

      tmp.path
    else
      false
    end
  end
end

if %x{whoami}.chomp != "root"
  abort "Must be root to execute commands"
end

if ARGV.length == 0
  Console.fatal CommandLineHelper.help
  abort
end

if Steps.valid?(ARGV)
  Steps.execute(ARGV)
else
  Console.fatal CommandLineHelper.invalid
  abort
end