server/deb_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 os, os.path, time, urllib

from autotest_lib.client.common_lib.error import *
from autotest_lib.server import kernel, utils


class DEBKernel(kernel.Kernel):
	"""
	This class represents a .deb 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(DEBKernel, self).__init__()


	def install(self, host, **kwargs):
		"""
		Install a kernel on the remote host.
		
		This will also invoke the guest's bootloader to set this
		kernel as the default kernel.
		
		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
				DEBKernel.get() with a .deb package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		
		remote_tmpdir = host.get_tmp_dir()
		basename = os.path.basename(self.source_material)
		remote_filename = os.path.join(remote_tmpdir, basename)
		host.send_file(self.source_material, remote_filename)
		host.run('dpkg -i "%s"' % (utils.sh_escape(remote_filename),))
		host.run('mkinitramfs -o "%s" "%s"' % (
			utils.sh_escape(self.get_initrd_name()), 
			utils.sh_escape(self.get_version()),))
		
		host.bootloader.add_kernel(self.get_image_name(), 
			initrd=self.get_initrd_name(), **kwargs)


	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
				DEBKernel.get() with a .deb package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		
		retval= utils.run('dpkg-deb -f "%s" version' % 
			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
				DEBKernel.get() with a .deb package.
		"""
		return "/boot/vmlinuz-%s" % (self.get_version(),)


	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
				DEBKernel.get() with a .deb package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		
		return "/boot/initrd.img-%s" % (self.get_version(),)
	
	def extract(self, host):
		"""Extract the kernel package.
		
		This function is only useful to access the content of the 
		package (for example the kernel image) without 
		installing it. It is not necessary to run this function to
		install the kernel.
		
		Args:
			host: the host on which to extract the kernel package.
		
		Returns:
			The full path to the temporary directory on host where 
			the package was extracted.
		
		Raises:
			AutoservError: no package has yet been obtained. Call
				DEBKernel.get() with a .deb package.
		"""
		if self.source_material is None:
			raise AutoservError("A kernel must first be \
			specified via get()")
		
		remote_tmpdir = host.get_tmp_dir()
		basename = os.path.basename(self.source_material)
		remote_filename = os.path.join(remote_tmpdir, basename)
		host.send_file(self.source_material, remote_filename)
		content_dir= os.path.join(remote_tmpdir, "contents")
		host.run('dpkg -x "%s" "%s"' % (utils.sh_escape(remote_filename), utils.sh_escape(content_dir),))
		
		return content_dir