server/rpm_kernel.py

#!/usr/bin/python
#
# Copyright 2007 Google Inc. Released under the GPL v2

"""
This module defines the Kernel class

	Kernel: an os kernel
"""

__author__ = """
mbligh@google.com (Martin J. Bligh),
poirier@google.com (Benjamin Poirier),
stutsman@google.com (Ryan Stutsman)"""


import kernel

import os
import os.path
import time
import urllib

import kernel
import utils

from common.error import *


class RPMKernel(kernel.Kernel):
	"""
	This class represents a .rpm pre-built kernel.

	It is used to obtain a built kernel and install it on a Host.

	Implementation details:
	This is a leaf class in an abstract class hierarchy, it must
	implement the unimplemented methods in parent classes.
	"""
	def __init__(self):
		super(RPMKernel, self).__init__()

	def install(self, host, label='autoserv',
		    default=False, kernel_args = ''):
		"""
		Install a kernel on the remote host.
		
		This will also invoke the guest's bootloader to set this
		kernel as the default kernel if default=True.
		
		Args:
			host: the host on which to install the kernel
			[kwargs]: remaining keyword arguments will be passed 
				to Bootloader.add_kernel()
		
		Raises:
			AutoservError: no package has yet been obtained. Call
				RPMKernel.get() with a .rpm package.
		"""
		if len(label) > 15:
			raise AutoservError("label for kernel is too long \
			(> 15 chars): %s" % label)
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		rpm = self.source_material

		remote_tmpdir = host.get_tmp_dir()	
		remote_rpm = os.path.join(remote_tmpdir, os.path.basename(rpm))
		rpm_package = utils.run('/usr/bin/rpm -q -p %s' % rpm).stdout
		vmlinuz = self.get_image_name()
		host.send_file(rpm, remote_rpm)
		host.run('rpm -e ' + rpm_package, ignore_status = True)
		host.run('rpm --force -i ' + remote_rpm)
		host.bootloader.remove_kernel(label)
		host.bootloader.add_kernel(vmlinuz, label,
					   args=kernel_args, default=default)
		if kernel_args:
			host.bootloader.add_args(label, kernel_args)
		if not default:
			host.bootloader.boot_once(label)


	def get_version(self):
		"""Get the version of the kernel to be installed.
		
		Returns:
			The version string, as would be returned 
			by 'make kernelrelease'.
		
		Raises:
			AutoservError: no package has yet been obtained. Call
				RPMKernel.get() with a .rpm package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		
		retval = utils.run('rpm -qpi %s | grep Version | \
		awk \'{print($3);}\'' % utils.sh_escape(self.source_material))
		return retval.stdout.strip()


	def get_image_name(self):
		"""Get the name of the kernel image to be installed.
		
		Returns:
			The full path to the kernel image file as it will be 
			installed on the host.
		
		Raises:
			AutoservError: no package has yet been obtained. Call
				RPMKernel.get() with a .rpm package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		
		vmlinuz = utils.run('rpm -q -l -p %s \
		| grep /boot/vmlinuz' % self.source_material).stdout.strip()
		return vmlinuz


	def get_initrd_name(self):
		"""Get the name of the initrd file to be installed.
		
		Returns:
			The full path to the initrd file as it will be 
			installed on the host. If the package includes no 
			initrd file, None is returned
		
		Raises:
			AutoservError: no package has yet been obtained. Call
				RPMKernel.get() with a .rpm package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")

		res = utils.run('rpm -q -l -p %s \
		| grep /boot/initrd' % self.source_material, ignore_status=True)
		if res.exit_status:
			return None
		return res.stdout.strip()