discover-host.rb.in

#!/usr/bin/env ruby
#
# vim: ts=2:sw=2:et
#
# Copyright (C) 2012-2013 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA  02110-1301, USA.  A copy of the GNU General Public License is
# also available at http://www.gnu.org/copyleft/gpl.html.

PACKAGE_NAME = '@PACKAGE_NAME@'
PACKAGE_VERSION = '@PACKAGE_VERSION@'
ENGINE_NAME = '@ENGINENAME@'
DEBUG = ('@PLUGIN_DEBUG@'.to_i == 1) rescue false
PROXY_CACHE = '/tmp/proxy_cache'

require 'fileutils'
require 'net/http'
require 'net/https'
require 'uri'
require 'socket'
require 'resolv'

# For comparison
require 'rubygems'
require 'facter'
require 'yaml'
require 'json'

BANNER = <<'EOS'



  _____
 |  ___|__  _ __ ___ _ __ ___   __ _ _ __
 | |_ / _ \| '__/ _ \ '_ ` _ \ / _` | '_ \
 |  _| (_) | | |  __/ | | | | | (_| | | | |
 |_|__\___/|_|  \___|_| |_| |_|\__,_|_| |_|
   |  _ \(_)___  ___ _____   _____ _ __ _   _
   | | | | / __|/ __/ _ \ \ / / _ \ '__| | | |
   | |_| | \__ \ (_| (_) \ V /  __/ |  | |_| |
   |____/|_|___/\___\___/ \_/ \___|_|   \__, |
                                        |___/


EOS

$start_time = Time.now
def time_prefix
  Time.at(Time.now - $start_time).strftime("[%_4s]")
rescue
  "[ ? ]"
end

def println msg
  puts "#{time_prefix} #{msg}\n"
end

def debug msg
  if DEBUG
    println msg
  end
end

def error msg
  $stderr.puts "#{time_prefix} #{msg}"
end

def cmdline option=nil, default=nil
  line = File.open("/proc/cmdline", 'r') { |f| f.read }
  if option
    result = line.split.map { |x| $1 if x.match(/^#{option}=(.*)/)}.compact
    result.size == 1 ? result.first : default
  else
    line
  end
end

def discover_server
  debug "Parsing kernel line: #{cmdline}"
  discover_by_url or discover_by_ip or
    discover_by_server or discover_by_dns_srv
end

# kept for backward compatibility
def discover_by_ip
  ip = cmdline 'foreman.ip'
  println "Discovered by PXE: #{ip}" if ip
  URI.parse("http://#{ip}")
rescue
  return nil
end

# kept for backward compatibility
def discover_by_server
  server = cmdline 'foreman.server'
  println "Discovered by SERVER: #{server}" if server
  URI.parse("http://#{server}")
rescue
  return nil
end

def discover_by_url
  url = cmdline 'foreman.url'
  println "Discovered by URL: #{url}" if url
  URI.parse(url)
rescue
  return nil
end

# SRV discovery will work only if DHCP returns valid search domain
def discover_by_dns_srv
  resolver = Resolv::DNS.new
  type = Resolv::DNS::Resource::IN::SRV
  result = resolver.getresources("_x-foreman._tcp", type).first
  hostname = result.target.to_s
  if result.port == 443
    scheme = 'https'
  else
    scheme = 'http'
  end
  uri = "#{scheme}://#{hostname}:#{result.port}"
  println "Discovered by SRV: #{uri}"
  URI.parse(uri)
rescue
  return nil
end

def upload
  uri = discover_server
  error "Could not determine Foreman instance, add kernel command option" unless uri
  println "Registering host with Foreman (#{uri})"
  http = Net::HTTP.new(uri.host, uri.port)
  if uri.scheme == 'https' then
    http.use_ssl = true
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE
  end
  req = Net::HTTP::Post.new("#{uri.path}/api/v2/discovered_hosts/facts", initheader = {'Content-Type' =>'application/json'})
  req.body = {'facts' => Facter.to_hash }.to_json
  response = http.request(req)
  if ['200','201'].include? response.code
    debug "Response from Foreman #{response.code}: #{response.body}"
    return true
  else
    error "Response from Foreman #{response.code}: #{response.body}"
    # <FIXME> - remove for Foreman 1.6
    # For backward compatibility reasons try to upload facts with the old API on /discovers
    ip = Facter.value('ipaddress')
    debug "Triggering import of facts from Foreman using old API (#{uri}, ip=#{ip})"
    req = Net::HTTP::Post.new("#{uri.path}/discovers")
    data = ip.nil? ? {} : {'ip' => ip}
    req.set_form_data(data)
    response = http.request(req)
    debug "Response from Foreman #{response.code}: #{response.body}"
    if response.code == "200"
      return true
    else
      return false
    end
    # </FIXME>
    return false
  end
rescue => e
  error "Could not send facts to Foreman: #{e}"
  return false
end

def write_cache(data)
  File.open(PROXY_CACHE, 'w') {|f| f.write(data) }
end

def read_cache
  File.read(PROXY_CACHE)
rescue => e
  "empty cache"
end

# Main

$stdout.reopen("/dev/tty1", "w")
$stderr.reopen("/dev/tty1", "w")

# Script was (re)started - delete old data
File.unlink(PROXY_CACHE) if File.exists?(PROXY_CACHE)

puts "\e[H\e[2J"
println BANNER
TAG = DEBUG ? 'D' : 'P'
println "This is Foreman Discovery #{PACKAGE_VERSION}-#{TAG}, tty1 is reserved for logs."
println "Hold on until all network interfaces are configured."
if DEBUG
  println "The image was build with debug support, you can switch over to tty2+ "
  println "and login as root/redhat or use ssh (password auth enabled)."
end
sleep DEBUG ? 10 : 30
println "Some interesting facts about this system:"
facts = Hash[Facter.to_hash.select {|k,v| k =~ /address|hardware|manufacturer|productname|memorytotal/}]
facts.keys.sort.each {|k| println " #{k}: #{facts[k]}"}
println "Logs from discovery services now follows:"

# loop, but only upload on changes
while true do
  uninteresting_facts=/kernel|operatingsystem|osfamily|ruby|path|time|swap|free|filesystem|version|selinux/i
  facts = Facter.to_hash.reject! {|k,v| k =~ uninteresting_facts }
  unless YAML.load(read_cache) == facts
    debug "Fact cache invalid, reloading to foreman"
    write_cache(YAML.dump(facts)) if upload
  end
  sleep DEBUG ? 30 : 120
end