Class: Bosh::Agent::Infrastructure::Vsphere::Settings

Inherits:
Object
  • Object
show all
Defined in:
lib/bosh_agent/infrastructure/vsphere/settings.rb

Constant Summary collapse

DEFAULT_CDROM_RETRY_WAIT = 
0.5

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Settings

Returns a new instance of Settings.



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 9

def initialize
  base_dir = Bosh::Agent::Config.base_dir
  @logger = Bosh::Agent::Config.logger
  @cdrom_retry_wait = DEFAULT_CDROM_RETRY_WAIT
  @cdrom_settings_mount_point = File.join(base_dir, 'bosh', 'settings')
  @cdrom_device = nil
end

Instance Attribute Details

#cdrom_retry_wait ⇒ Object

Returns the value of attribute cdrom_retry_wait.



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 7

def cdrom_retry_wait
  @cdrom_retry_wait
end

Instance Method Details

#cdrom_device ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 17

def cdrom_device
  unless @cdrom_device
    # only do this when not already done
    cd_drive = File.read("/proc/sys/dev/cdrom/info").slice(/drive name:\s*\S*/).slice(/\S*\z/)
    @cdrom_device = "/dev/#{cd_drive.strip}"
  end
  @cdrom_device
end

#check_cdrom ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 49

def check_cdrom
  # Below we do a number of retries to work around race conditions both
  # when inserting a virtual cdrom in vSphere and how udev handles
  # detection of the new media.
  #
  # Part of what the udev cdrom-id helper will do is to open /dev/cdrom
  # with O_EXCL, which will give us EBUSY - however, the exact timing of
  # this is a little harder - so we retry.

  # First give the cdrom media a little time to get detected
  5.times do
    begin
      read_cdrom_byte
      break
    rescue => e
      @logger.info("Waiting for #{cdrom_device} (ENOMEDIUM): #{e.inspect}")
    end
    sleep @cdrom_retry_wait
  end

  # Second read - invoke udevadmin settle
  begin
    read_cdrom_byte
  rescue => e
    # Do nothing
  end

  begin
    # udevadm settle default timeout is 120 seconds
    udevadm_settle_out = udevadm_settle
    @logger.info("udevadm: #{udevadm_settle_out}")
  rescue
    raise Bosh::Agent::LoadSettingsError, "udevadm failed: #{e.inspect}"
  end

  # Read successfuly from cdrom for 2.5 seconds
  5.times do
    begin
      read_cdrom_byte
    rescue Errno::EBUSY
      @logger.info("Waiting for udev cdrom-id (EBUSY)")
      # do nothing
    rescue Errno::ENOMEDIUM # 1.8: Errno::E123
      @logger.info("Waiting for #{cdrom_device} (ENOMEDIUM or ENOTBLK)")
      # do nothing
    end
    sleep @cdrom_retry_wait
  end

  begin
    read_cdrom_byte
  rescue Errno::EBUSY, Errno::ENOMEDIUM # 1.8: Errno::E123
    raise Bosh::Agent::LoadSettingsError, "No bosh cdrom env: #{e.inspect}"
  end
end

#create_cdrom_settings_mount_point ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 119

def create_cdrom_settings_mount_point
  FileUtils.mkdir_p(@cdrom_settings_mount_point)
  FileUtils.chmod(0700, @cdrom_settings_mount_point)
end

#eject_cdrom ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 134

def eject_cdrom
  Bosh::Exec.sh "eject #{cdrom_device}"
end

#load_cdrom_settings ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 30

def load_cdrom_settings
  check_cdrom
  create_cdrom_settings_mount_point
  mount_cdrom

  env_file = File.join(@cdrom_settings_mount_point, 'env')

  begin
    settings_json = File.read(env_file)
    @settings = Yajl::Parser.new.parse(settings_json)
  rescue
    raise Bosh::Agent::LoadSettingsError, 'Failed to read/write env/settings.json'
  ensure
    umount_cdrom
    eject_cdrom
  end
  @settings
end

#load_settings ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 26

def load_settings
  load_cdrom_settings
end

#mount_cdrom ⇒ Object

Raises:



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 124

def mount_cdrom
  result = Bosh::Exec.sh "mount #{cdrom_device} #@cdrom_settings_mount_point 2>&1"
  raise Bosh::Agent::LoadSettingsError,
    "Failed to mount settings on #@cdrom_settings_mount_point: #{result.output}" if result.failed?
end

#read_cdrom_byte ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 115

def read_cdrom_byte
  File.read(cdrom_device, 1)
end

#udevadm_settle ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 105

def udevadm_settle
  if File.exists? "/sbin/udevadm"
    Bosh::Exec.sh "/sbin/udevadm settle"
  elsif File.exists? "/sbin/udevsettle"
    Bosh::Exec.sh "/sbin/udevsettle"
  else
    raise Bosh::Agent::LoadSettingsError, "No udevsettle"
  end
end

#umount_cdrom ⇒ Object 



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# File 'lib/bosh_agent/infrastructure/vsphere/settings.rb', line 130

def umount_cdrom
  Bosh::Exec.sh "umount #@cdrom_settings_mount_point 2>&1"
end