Module: StateTransitionHelper

Included in:
ScriptExecutionState
Defined in:
lib/help/state_transition_helper.rb

Instance Method Summary collapse

Instance Method Details

#attach_volume(volume_id, instance_id, temp_device_name) ⇒ Object

Attaches an EBS volume to an instance Input Parameters:

  • volume_id => EC2 ID for the EBS Volume to be attached

  • instance_id => EC2 ID for the instance to which the volume is supposed to be attached to

  • temp_device_name => device name to be used for attaching (e.g. /dev/sdj1)



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# File 'lib/help/state_transition_helper.rb', line 232

def attach_volume(volume_id, instance_id, temp_device_name)
  post_message("going to attach volume #{volume_id} to instance #{instance_id} on device #{temp_device_name}...")
  @logger.debug "attach volume #{volume_id} to instance #{instance_id} on device #{temp_device_name}"
  ec2_handler().attach_volume(:volume_id => volume_id,
    :instance_id => instance_id,
    :device => temp_device_name
  )
  done = false
  while !done
    sleep(5)
    #TODO: check for timeout?
    res = ec2_handler().describe_volumes(:volume_id => volume_id)
    state = res['volumeSet']['item'][0]['status']
    @logger.debug "storage attaching: #{state}"
    if state == 'in-use'
      done = true
    end
  end
  post_message("volume successfully attached")
end

#connect(dns_name, user_name, ssh_keyfile = nil, ssh_keydata = nil) ⇒ Object

Connects to the remote host via SSH. Params:

  • dns_name => machine to connect to

  • user_name => name to be used for connection

  • ssh_keyfile => key-file used for ssh

  • ssh_keydata => contents of key-file (either use ssh_keyfile or ssh_keydata)

Returns:

  • OS of the connected machine



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# File 'lib/help/state_transition_helper.rb', line 40

def connect(dns_name, user_name, ssh_keyfile = nil, ssh_keydata = nil)
  post_message("connecting '#{user_name}' to #{dns_name}...")
  connected = false
  last_connection_problem = ""
  remaining_trials = 5
  while !connected && remaining_trials > 0
    remaining_trials -= 1
    if ssh_keyfile != nil
      begin
        @logger.info("connecting using keyfile")
        remote_handler().connect_with_keyfile(dns_name, ssh_keyfile)
        connected = true
      rescue Exception => e
        @logger.info("connection failed due to #{e}")
        last_connection_problem = "#{e}"
        @logger.debug(e.backtrace.select(){|line| line.include?("state_transition_helper")}.join("\n"))
      end
    elsif ssh_keydata != nil
      begin
        @logger.info("connecting using keydata")
        remote_handler().connect(dns_name, user_name, ssh_keydata)
        connected = true
      rescue Exception => e
        @logger.info("connection failed due to #{e}")
        last_connection_problem = "#{e}"
        @logger.debug(e.backtrace.select(){|line| line.include?("state_transition_helper")}.join("\n"))
      end
    else
      raise Exception.new("no key information specified")
    end
    if !connected
      sleep(20) #try again
    end
  end
  if !connected
    raise Exception.new("connection attempts stopped (#{last_connection_problem})")
  end
  os = remote_handler().retrieve_os()
  sudo = remote_handler().use_sudo ? " [sudo]" : ""
  post_message("connected to #{dns_name}#{sudo}. OS installed is #{os}")
  @logger.info "connected to #{dns_name}#{sudo}"
  return os
end

#copy_distribution(destination_path) ⇒ Object

Copy all files of a running linux distribution via rsync to a mounted directory Input Parameters:

  • destination_path => where to copy to



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# File 'lib/help/state_transition_helper.rb', line 406

def copy_distribution(destination_path)
  post_message("going to start copying files to #{destination_path}. This may take quite a time...")
  @logger.debug "start copying to #{destination_path}"
  start = Time.new.to_i
  if remote_handler().tools_installed?("rsync")
    @logger.debug "use rsync command line"
    status = remote_handler().local_rsync("/", "#{destination_path}", "#{destination_path}")
    status = remote_handler().local_rsync("/dev/", "#{destination_path}/dev/")
    if status == false
      raise Exception.new("failed to copy distribution remotely using rsync")
    end
  else
    @logger.debug "use cp command line"
    status = remote_handler().local_rcopy("/", "#{destination_path}", "/proc /sys /dev /mnt")
    if status == false
      raise Exception.new("failed to copy distribution remotely using cp")
    end
    status = remote_handler().mkdir("#{destination_path}/proc")
    status = remote_handler().mkdir("#{destination_path}/sys")
    status = remote_handler().mkdir("#{destination_path}/mnt")
    status = remote_handler().mkdir("#{destination_path}/dev")
  end
  endtime = Time.new.to_i
  @logger.info "copy took #{(endtime-start)}s"
  post_message("copying is done (took #{endtime-start})s")
end

#create_fs(dns_name, device) ⇒ Object

Create a file-system on a given machine (assumes to be connected already). Input Parameters:

  • dns_name => IP used

  • device => device to be used for file-system creation (e.g. /dev/sdj)



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# File 'lib/help/state_transition_helper.rb', line 352

def create_fs(dns_name, device)
  post_message("going to create filesystem on #{dns_name} to #{device}...")
  @logger.debug "create filesystem on #{dns_name} to #{device}"
  status = remote_handler().create_filesystem("ext3", device)
  if status == false
    raise Exception.new("failed to create ext3 filesystem on #{device} device on #{dns_name}")
  end
  post_message("filesystem system successfully created")
end

#create_snapshot(volume_id, description = "") ⇒ Object

Creates a snapshot for an EBS volume.

Input Parameters

  • volume_id => EC2 ID for the EBS volume to be snapshotted

Returns:

  • snapshot_id => EC2 ID for the snapshot created



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# File 'lib/help/state_transition_helper.rb', line 291

def create_snapshot(volume_id, description = "")
  post_message("going to create a snapshot for volume #{volume_id}...")
  @logger.debug "create snapshot for volume #{volume_id}"
  res = ec2_handler().create_snapshot(:volume_id => volume_id,
    :description => description)
  snapshot_id = res['snapshotId']
  @logger.info "snapshot_id = #{snapshot_id}"
  done = false
  while !done
    sleep(5)
    #TODO: check for timeout?
    res = ec2_handler().describe_snapshots(:snapshot_id => snapshot_id)
    @logger.debug "snapshot creating: #{res.inspect}"
    if res['snapshotSet']['item'][0]['status'] == 'completed'
      done = true
    end
  end
  post_message("snapshot is done with ID=#{snapshot_id}")
  return snapshot_id
end

#create_volume(availability_zone, size = "10") ⇒ Object

Creates a new EBS volume. Input Parameters:

  • availability_zone => availability zone for the volume

  • size => size in Gigabytes

Returns

  • volume_id => EC2 EBS Volume ID



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# File 'lib/help/state_transition_helper.rb', line 180

def create_volume(availability_zone, size = "10")
  post_message("going to create a new EBS volume of size #{size}GB...")
  @logger.debug "create volume in zone #{availability_zone}"
  res = ec2_handler().create_volume(:availability_zone => availability_zone, :size => size.to_s)
  volume_id = res['volumeId']
  started = false
  while !started
    sleep(5)
    #TODO: check for timeout?
    res = ec2_handler().describe_volumes(:volume_id => volume_id)
    state = res['volumeSet']['item'][0]['status']
    @logger.debug "volume state #{state}"
    if state == 'available'
      started = true
    end
  end
  post_message("EBS volume #{volume_id} is ready")
  return volume_id
end

#create_volume_from_snapshot(snapshot_id, availability_zone) ⇒ Object

Creates a new EBS volume from a snapshot ID. Input Parameters:

  • availability_zone => availability zone for the volume

  • size => size of the volume to be created

  • snapshot_id => EC2 Snapshot ID used to create the volume

Returns

  • volume_id => EC2 EBS Volume ID created



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# File 'lib/help/state_transition_helper.rb', line 207

def create_volume_from_snapshot(snapshot_id, availability_zone)
  post_message("going to create a new EBS volume from the specified snapshot...")
  @logger.debug "create volume in zone #{availability_zone}"
  res = ec2_handler().create_volume(:snapshot_id => snapshot_id, :availability_zone => availability_zone)
  volume_id = res['volumeId']
  started = false
  while !started
    sleep(5)
    #TODO: check for timeout?
    res = ec2_handler().describe_volumes(:volume_id => volume_id)
    state = res['volumeSet']['item'][0]['status']
    @logger.debug "volume state #{state}"
    if state == 'available'
      started = true
    end
  end
  post_message("EBS volume #{volume_id} is ready")
  return volume_id
end

#delete_snapshot(snapshot_id) ⇒ Object

Deletes a snapshot.



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# File 'lib/help/state_transition_helper.rb', line 313

def delete_snapshot(snapshot_id)
  post_message("going to delete snapshot #{snapshot_id}...")
  @logger.info("going to delete snapshot #{snapshot_id}...")
  ec2_handler().delete_snapshot(:snapshot_id => snapshot_id)
  @logger.info("snapshot #{snapshot_id} deleted")
  post_message("snapshot #{snapshot_id} deleted")
end

#delete_volume(volume_id) ⇒ Object

Delete an EBS volume. Input Parameters:

  • volume_id => EC2 ID for the EBS Volume to be deleted



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# File 'lib/help/state_transition_helper.rb', line 279

def delete_volume(volume_id)
  post_message("going to delete volume #{volume_id} (no longer needed)...")
  @logger.debug "delete volume #{volume_id}"
  ec2_handler().delete_volume(:volume_id => volume_id)
  post_message("volume #{volume_id} deleted")
end

#detach_volume(volume_id, instance_id) ⇒ Object

Detach an EBS volume from an instance. Input Parameters:

  • volume_id => EC2 ID for the EBS Volume to be detached

  • instance_id => EC2 ID for the instance to detach from



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# File 'lib/help/state_transition_helper.rb', line 257

def detach_volume(volume_id, instance_id)
  post_message("going to detach volume #{volume_id}...")
  @logger.debug "detach volume #{volume_id}"
  ec2_handler().detach_volume(:volume_id => volume_id,
    :instance_id => instance_id
  )
  done = false
  while !done
    sleep(3)
    #TODO: check for timeout?
    res = ec2_handler().describe_volumes(:volume_id => volume_id)
    @logger.debug "volume detaching: #{res.inspect}"
    if res['volumeSet']['item'][0]['status'] == 'available'
      done = true
    end
  end
  post_message("volume #{volume_id} detached.")
end

#determine_file(ip, user_name, ssh_keydata, file_candidates) ⇒ Object

From a list of existing files, return the first that exists



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# File 'lib/help/state_transition_helper.rb', line 473

def determine_file(ip, user_name, ssh_keydata, file_candidates)
  connect(ip, user_name, nil, ssh_keydata)
  begin
    file_candidates.each() {|file_path|
      if remote_handler().file_exists?(file_path)
        return file_path
      end
    }
    return nil
  rescue
    raise
  ensure
    disconnect()
  end
end

#disconnect ⇒ Object

If a remote command handler is connected, disconnect him silently.



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# File 'lib/help/state_transition_helper.rb', line 85

def disconnect
  begin
    remote_handler().disconnect()
  rescue
  end
  self.remote_handler= nil
end

#ec2_handler ⇒ Object 



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# File 'lib/help/state_transition_helper.rb', line 506

def ec2_handler()
  if @ec2_handler == nil
    @ec2_handler = @context[:ec2_api_handler]
  end
  @ec2_handler
end

#ec2_handler=(ec2_handler) ⇒ Object 



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# File 'lib/help/state_transition_helper.rb', line 513

def ec2_handler=(ec2_handler)
  @ec2_handler = ec2_handler
end

#launch_instance(ami_id, key_name, security_group_name, ec2_handler = nil) ⇒ Object

Launch an instance based on an AMI ID Input Parameters:

  • ami_id => ID of the AMI to be launched

  • key_name => name of the key to access the instance

  • security_group_name => name of the security group to be used

Returned information:

  • instance_id => ID of the started instance

  • dns_name => DNS name of the started instance

  • availability_zone => Availability zone of the started instance

  • kernel_id => EC2 Kernel ID of the started instance

  • ramdisk_id => EC2 Ramdisk ID of the started instance

  • architecture => architecture (e.g. 386i, 64x) of the started instance



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# File 'lib/help/state_transition_helper.rb', line 105

def launch_instance(ami_id, key_name, security_group_name, ec2_handler = nil)
  ec2_handler = ec2_handler() if ec2_handler == nil
  post_message("starting up instance to execute the script (AMI = #{ami_id}) ...")
  @logger.debug "start up AMI #{ami_id}"
  # find out the image architecture first
  image_props = ec2_handler.describe_images(:image_id => ami_id)
  architecture = image_props['imagesSet']['item'][0]['architecture']
  instance_type = "m1.small"
  if architecture != "i386"
    instance_type = "m1.large"
  end
  arch_log_msg = "Architecture of image #{ami_id} is #{architecture}. Use instance_type #{instance_type}."
  @logger.info arch_log_msg
  post_message(arch_log_msg)
  # now start it
  res = ec2_handler.run_instances(:image_id => ami_id,
    :security_group => security_group_name, :key_name => key_name,
    :instance_type => instance_type
  )
  instance_id = res['instancesSet']['item'][0]['instanceId']
  @logger.info "started instance #{instance_id}"
  post_message("Started instance #{instance_id}. wait until it is ready...")
  #availability_zone , key_name/group_name
  started = false
  while started == false
    sleep(5)
    res = ec2_handler.describe_instances(:instance_id => instance_id)
    state = res['reservationSet']['item'][0]['instancesSet']['item'][0]['instanceState']
    @logger.info "instance is in state #{state['name']} (#{state['code']})"
    if state['code'].to_i == 16
      started = true
      post_message("instance is up and running")
      dns_name = res['reservationSet']['item'][0]['instancesSet']['item'][0]['dnsName']
      availability_zone = res['reservationSet']['item'][0]['instancesSet']['item'][0]['placement']['availabilityZone']
      kernel_id = res['reservationSet']['item'][0]['instancesSet']['item'][0]['kernelId']
      ramdisk_id = res['reservationSet']['item'][0]['instancesSet']['item'][0]['ramdiskId']
      architecture = res['reservationSet']['item'][0]['instancesSet']['item'][0]['architecture']
    elsif state['code'].to_i != 0
      post_message("instance in state #{state['name']}")
      raise Exception.new('instance failed to start up')
    else
      post_message("instance still starting up...")
    end
  end
  return instance_id, dns_name, availability_zone, kernel_id, ramdisk_id, architecture
end

#mount_fs(mount_point, device) ⇒ Object

Create a file-system on a given machine (assumes to be connected already). Input Parameters:

  • mount_point => directory to be mounted on the device

  • device => device used for mounting



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# File 'lib/help/state_transition_helper.rb', line 366

def mount_fs(mount_point, device)
  post_message("going to mount #{device} on #{mount_point}...")
  @logger.debug "mount #{device} on #{mount_point}"
  if !remote_handler.file_exists?(mount_point)
    remote_handler().mkdir(mount_point)
  end
  remote_handler().mount(device, mount_point)
  trials = 3
  mounted = false
  while trials > 0
    sleep(5) #give mount some time
    if remote_handler().drive_mounted?(mount_point)
      mounted = true
      break
    end
    trials -= trials
  end
  if !mounted
    raise Exception.new("drive #{mount_point} not mounted")
  end
  post_message("mount successful")
end

#register_snapshot(snapshot_id, name, root_device_name, description, kernel_id, ramdisk_id, architecture) ⇒ Object

Registers a snapshot as EBS-booted AMI. Input Parameters:

  • snapshot_id => EC2 Snapshot ID used to be used

  • name => name of the AMI to be created

  • root_device_name => Root device name (e.g. /dev/sdj) to be used for AMI registration

  • description => description of the AMI to be created

  • kernel_id => EC2 Kernel ID to be used for AMI registration

  • ramdisk_id => EC2 Ramdisk ID to be used for AMI registration

  • architecture => architecture (e.g. 386i, 64x) to be used for AMI registration

Returns:

  • image_id => ID of the AMI created and registered



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# File 'lib/help/state_transition_helper.rb', line 332

def register_snapshot(snapshot_id, name, root_device_name, description, kernel_id, ramdisk_id, architecture)
  post_message("going to register snapshot #{snapshot_id}...")
  @logger.debug "register snapshot #{snapshot_id} as #{name}"
  res = ec2_handler().register_image_updated(:snapshot_id => snapshot_id,
    :kernel_id => kernel_id, :architecture => architecture,
    :root_device_name => root_device_name,
    :description => description, :name => name,
    :ramdisk_id => ramdisk_id
  )
  @logger.debug "result of registration = #{res.inspect}"
  image_id = res['imageId']
  @logger.info "resulting image_id = #{image_id}"
  post_message("snapshot #{snapshot_id} successfully registered as AMI #{image_id} ")
  return image_id
end

#remote_copy(user_name, keyname, source_dir, dest_machine, dest_dir) ⇒ Object 



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# File 'lib/help/state_transition_helper.rb', line 448

def remote_copy(user_name, keyname, source_dir, dest_machine, dest_dir)
  post_message("going to remote copy all files from volume. This may take some time...")
  key_path_candidates = ["/#{user_name}/.ssh/", "/home/#{user_name}/.ssh/"]
  key_path_candidates.each() {|key_path|
    key_file = "#{key_path}#{keyname}.pem"
    if remote_handler().file_exists?(key_path)
      if remote_handler().tools_installed?("rsync")
        @logger.debug "use rsync command on #{key_file}"
        remote_handler().remote_rsync(key_file, source_dir, dest_machine, dest_dir)
      else
        @logger.debug "use scp command #{key_file}"
        remote_handler().scp(key_file, source_dir, dest_machine, dest_dir)
      end
      break
    end
  }
  post_message("remote copy operation done")
end

#remote_handler ⇒ Object

setting/retrieving handlers



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# File 'lib/help/state_transition_helper.rb', line 491

def remote_handler()
  if @remote_handler == nil
    if @context[:remote_command_handler] == nil
      @context[:remote_command_handler] = RemoteCommandHandler.new
    else
      @remote_handler = @context[:remote_command_handler]
    end
  end
  @remote_handler
end

#remote_handler=(remote_handler) ⇒ Object 



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# File 'lib/help/state_transition_helper.rb', line 502

def remote_handler=(remote_handler)
  @remote_handler = remote_handler
end

#shut_down_instance(instance_id) ⇒ Object

Shuts down an instance. Input Parameters:

  • instance_id => ID of the instance to be shut down



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# File 'lib/help/state_transition_helper.rb', line 155

def shut_down_instance(instance_id)
  post_message("going to shut down the temporary instance #{instance_id}...")
  @logger.debug "shutdown instance #{instance_id}"
  res = ec2_handler().terminate_instances(:instance_id => instance_id)
  done = false
  while done == false
    sleep(5)
    res = ec2_handler().describe_instances(:instance_id => instance_id)
    state = res['reservationSet']['item'][0]['instancesSet']['item'][0]['instanceState']
    @logger.debug "instance in state #{state['name']} (#{state['code']})"
    if state['code'].to_i == 48
      done = true
    elsif state['code'].to_i != 32
      raise Exception.new('instance failed to shut down')
    end
  end
  post_message("instance #{instance_id} is terminated")
end

#unmount_fs(mount_point) ⇒ Object

Unmount a drive Input Parameters:

  • mount_point => directory to be unmounted



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# File 'lib/help/state_transition_helper.rb', line 392

def unmount_fs(mount_point)
  post_message("Going to unmount ...")
  @logger.debug "unmount #{mount_point}"
  remote_handler().umount(mount_point)
  sleep(2) #give umount some time
  if remote_handler().drive_mounted?(mount_point)
    raise Exception.new("drive #{mount_point} not unmounted")
  end
  post_message("device unmounted")
end

#upload_file(ip, user, key_data, file, target_file) ⇒ Object 



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# File 'lib/help/state_transition_helper.rb', line 467

def upload_file(ip, user, key_data, file, target_file)
  post_message("going to upload #{file} to #{user}@#{ip}:#{target_file}")
  remote_handler().upload(ip, user, key_data, file, target_file)
end

#zip_volume(source_dir, zip_file_dest, zip_file_name) ⇒ Object

Zips all files on a mounted-directory into a file Input Parameters:

  • source_dir => where to copy from

  • zip_file_dest => path where the zip-file should be stored

# zip_file_name => name of the zip file (without .zip suffix)



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# File 'lib/help/state_transition_helper.rb', line 438

def zip_volume(source_dir, zip_file_dest, zip_file_name)
  post_message("going to zip the EBS volume")
  stderr = remote_handler().zip(source_dir, zip_file_dest+"/"+zip_file_name)
  if stderr.size > 0
    @logger.info("zip operation generated error and might not be complete. output: #{stderr.join("\n")}")
    post_message("zip operation generated error and might not be complete. output: #{stderr.join("\n")}")
  end
  post_message("EBS volume successfully zipped")
end