Merge branch 'liw/deployment-refactor' of git://git.baserock.org/baserock/baserock/morph

10 files changed, 714 insertions, 1 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index 0f60642c..4446720e 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -73,4 +73,6 @@ import util
 
 import yamlparse
 
+import writeexts
+
 import app  # this needs to be last
diff --git a/morphlib/exts/kvm.write b/morphlib/exts/kvm.write
new file mode 100755
index 00000000..09a7d224
--- /dev/null
+++ b/morphlib/exts/kvm.write
@@ -0,0 +1,110 @@
+#!/usr/bin/python
+# Copyright (C) 2012-2013  Codethink Limited
+#
+# 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 Morph deployment write extension for deploying to KVM+libvirt.'''
+
+
+import cliapp
+import os
+import re
+import sys
+import tempfile
+import urlparse
+
+import morphlib.writeexts
+
+
+class KvmPlusSshWriteExtension(morphlib.writeexts.WriteExtension):
+
+    '''Create a KVM/LibVirt virtual machine during Morph's deployment.
+    
+    The location command line argument is the pathname of the disk image
+    to be created. The user is expected to provide the location argument
+    using the following syntax:
+    
+        kvm+ssh://HOST/GUEST/PATH
+        
+    where:
+    
+    * HOST is the host on which KVM/LibVirt is running
+    * GUEST is the name of the guest virtual machine on that host
+    * PATH is the path to the disk image that should be created,
+      on that host
+  
+    The extension will connect to HOST via ssh to run libvirt's
+    command line management tools.
+    
+    '''
+
+    def process_args(self, args):
+        if len(args) != 2:
+            raise cliapp.AppException('Wrong number of command line args')
+        
+        temp_root, location = args
+        ssh_host, vm_name, vm_path = self.parse_location(location)
+        
+        fd, raw_disk = tempfile.mkstemp()
+        os.close(fd)
+        self.create_local_system(temp_root, raw_disk)
+        
+        try:
+            self.transfer(raw_disk, ssh_host, vm_path)
+            self.create_libvirt_guest(ssh_host, vm_name, vm_path)
+        except BaseException:
+            sys.stderr.write('Error deploying to libvirt')
+            os.remove(raw_disk)
+            raise
+        else:
+            os.remove(raw_disk)
+
+        self.status(
+            msg='Virtual machine %(vm_name)s has been created',
+            vm_name=vm_name)
+
+    def parse_location(self, location):
+        '''Parse the location argument to get relevant data.'''
+        
+        x = urlparse.urlparse(location)
+        if x.scheme != 'kvm+ssh':
+            raise cliapp.AppException(
+                'URL schema must be vbox+ssh in %s' % location)
+        m = re.match('^/(?P<guest>[^/]+)(?P<path>/.+)$', x.path)
+        if not m:
+            raise cliapp.AppException('Cannot parse location %s' % location)
+        return x.netloc, m.group('guest'), m.group('path')
+
+    def transfer(self, raw_disk, ssh_host, vm_path):
+        '''Transfer raw disk image to libvirt host.'''
+
+        self.status(msg='Transfer disk image')
+        target = '%s:%s' % (ssh_host, vm_path)
+        with open(raw_disk, 'rb') as f:
+            cliapp.runcmd(['rsync', '-zS', raw_disk, target])
+
+    def create_libvirt_guest(self, ssh_host, vm_name, vm_path):
+        '''Create the libvirt virtual machine.'''
+        
+        self.status(msg='Create libvirt/kvm virtual machine')
+        cliapp.runcmd(
+            ['ssh', ssh_host, 
+             'virt-install', '--connect qemu:///system', '--import',
+             '--name', vm_name, '--ram', '1024', '--vnc', '--noreboot',
+             '--disk path=%s,bus=ide' % vm_path])
+
+
+KvmPlusSshWriteExtension().run()
+
diff --git a/morphlib/exts/rawdisk.write b/morphlib/exts/rawdisk.write
new file mode 100755
index 00000000..a55473f2
--- /dev/null
+++ b/morphlib/exts/rawdisk.write
@@ -0,0 +1,49 @@
+#!/usr/bin/python
+# Copyright (C) 2012-2013  Codethink Limited
+#
+# 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 Morph deployment write extension for raw disk images.'''
+
+
+import os
+import sys
+import time
+import tempfile
+
+import morphlib.writeexts
+
+
+class RawDiskWriteExtension(morphlib.writeexts.WriteExtension):
+
+    '''Create a raw disk image during Morph's deployment.
+    
+    The location command line argument is the pathname of the disk image
+    to be created.
+    
+    '''
+
+    def process_args(self, args):
+        if len(args) != 2:
+            raise cliapp.AppException('Wrong number of command line args')
+        
+        temp_root, location = args
+        
+        self.create_local_system(temp_root, location)
+        self.status(msg='Disk image has been created at %s' % location)
+
+
+RawDiskWriteExtension().run()
+
diff --git a/morphlib/exts/set-hostname.configure b/morphlib/exts/set-hostname.configure
new file mode 100755
index 00000000..e44c5d56
--- /dev/null
+++ b/morphlib/exts/set-hostname.configure
@@ -0,0 +1,27 @@
+#!/bin/sh
+# Copyright (C) 2013  Codethink Limited
+#
+# 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.
+
+
+# Set hostname on system from HOSTNAME.
+
+
+set -e
+
+if [ -n "$HOSTNAME" ]
+then
+    echo "$HOSTNAME" > "$1/etc/hostname"
+fi
+
diff --git a/morphlib/exts/virtualbox-ssh.write b/morphlib/exts/virtualbox-ssh.write
new file mode 100755
index 00000000..c21dcc57
--- /dev/null
+++ b/morphlib/exts/virtualbox-ssh.write
@@ -0,0 +1,129 @@
+#!/usr/bin/python
+# Copyright (C) 2012-2013  Codethink Limited
+#
+# 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 Morph deployment write extension for deploying to VirtualBox via ssh.
+
+VirtualBox is assumed to be running on a remote machine, which is
+accessed over ssh. The machine gets created, but not started.
+
+'''
+
+
+import cliapp
+import os
+import re
+import time
+import tempfile
+import urlparse
+
+import morphlib.writeexts
+
+
+class VirtualBoxPlusSshWriteExtension(morphlib.writeexts.WriteExtension):
+
+    '''Create a VirtualBox virtual machine during Morph's deployment.
+    
+    The location command line argument is the pathname of the disk image
+    to be created. The user is expected to provide the location argument
+    using the following syntax:
+    
+        vbox+ssh://HOST/GUEST/PATH
+        
+    where:
+    
+    * HOST is the host on which VirtualBox is running
+    * GUEST is the name of the guest virtual machine on that host
+    * PATH is the path to the disk image that should be created,
+      on that host
+  
+    The extension will connect to HOST via ssh to run VirtualBox's
+    command line management tools.
+    
+    '''
+
+    def process_args(self, args):
+        if len(args) != 2:
+            raise cliapp.AppException('Wrong number of command line args')
+        
+        temp_root, location = args
+        ssh_host, vm_name, vdi_path = self.parse_location(location)
+        
+        fd, raw_disk = tempfile.mkstemp()
+        os.close(fd)
+        self.create_local_system(temp_root, raw_disk)
+
+        try:
+            self.transfer_and_convert_to_vdi(
+                raw_disk, size, ssh_host, vdi_path)
+            self.create_virtualbox_guest(ssh_host, vm_name, vdi_path)
+        except BaseException:
+            sys.stderr.write('Error deploying to VirtualBox')
+            os.remove(raw_disk)
+            raise
+        else:
+            os.remove(raw_disk)
+
+        self.status(
+            msg='Virtual machine %(vm_name)s has been created',
+            vm_name=vm_name)
+
+    def parse_location(self, location):
+        '''Parse the location argument to get relevant data.'''
+        
+        x = urlparse.urlparse(location)
+        if x.scheme != 'vbox+ssh':
+            raise cliapp.AppException(
+                'URL schema must be vbox+ssh in %s' % location)
+        m = re.match('^/(?P<guest>[^/]+)(?P<path>/.+)$', x.path)
+        if not m:
+            raise cliapp.AppException('Cannot parse location %s' % location)
+        return x.netloc, m.group('guest'), m.group('path')
+
+    def transfer_and_convert_to_vdi(self, raw_disk, size, ssh_host, vdi_path):
+        '''Transfer raw disk image to VirtualBox host, and convert to VDI.'''
+
+        self.status(msg='Transfer disk and convert to VDI')
+        with open(raw_disk, 'rb') as f:
+            cliapp.runcmd(
+                ['ssh', ssh_host, 
+                 'VBoxManage', 'convertfromraw', 'stdin', vdi_path, str(size)],
+                stdin=f)
+
+    def create_virtualbox_guest(self, ssh_host, vm_name, vdi_path):
+        '''Create the VirtualBox virtual machine.'''
+        
+        self.status(msg='Create VirtualBox virtual machine')
+
+        commands = [
+            ['createvm', '--name', vm_name, '--ostype', 'Linux26_64',
+             '--register'],
+            ['modifyvm', vm_name, '--ioapic', 'on', '--memory', '1024',
+             '--nic1', 'nat'],
+            ['storagectl', vm_name, '--name', '"SATA Controller"',
+             '--add', 'sata',  '--bootable', 'on', '--sataportcount', '2'],
+            ['storageattach', vm_name, '--storagectl', '"SATA Controller"',
+             '--port', '0', '--device', '0', '--type', 'hdd', '--medium',
+             vdi_path],
+        ]
+        
+        for command in commands:
+            argv = ['ssh', ssh_host, 'VBoxManage'] + command
+            cliapp.runcmd(argv)
+
+
+VirtualBoxPlusSshWriteExtension().run()
+
diff --git a/morphlib/morph2.py b/morphlib/morph2.py
index 3a3ad679..6e24765e 100644
--- a/morphlib/morph2.py
+++ b/morphlib/morph2.py
@@ -49,7 +49,8 @@ class Morphology(object):
             ('strata', []),
             ('description', ''),
             ('arch', None),
-            ('system-kind', None)
+            ('system-kind', None),
+            ('configuration-extensions', []),
         ]
     }
 
diff --git a/morphlib/plugins/__init__.py b/morphlib/plugins/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/morphlib/plugins/__init__.py
diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index 58aa8931..0f07c431 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -331,6 +331,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
                 'description',
                 'disk-size',
                 '_disk-size',
+                'configuration-extensions',
             ],
             'stratum': [
                 'kind',
diff --git a/morphlib/plugins/deploy_plugin.py b/morphlib/plugins/deploy_plugin.py
new file mode 100644
index 00000000..79715e13
--- /dev/null
+++ b/morphlib/plugins/deploy_plugin.py
@@ -0,0 +1,209 @@
+# Copyright (C) 2013  Codethink Limited
+#
+# 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.
+
+
+import cliapp
+import gzip
+import os
+import shutil
+import tarfile
+import tempfile
+import urlparse
+import uuid
+
+import morphlib
+
+# UGLY HACK: We need to re-use some code from the branch and merge
+# plugin, so we import and instantiate that plugin. This needs to
+# be fixed by refactoring the codebase so the shared code is in
+# morphlib, not in a plugin. However, this hack lets us re-use
+# code without copying it.
+import morphlib.plugins.branch_and_merge_plugin
+
+
+class DeployPlugin(cliapp.Plugin):
+
+    def enable(self):
+        self.app.add_subcommand(
+            'deploy', self.deploy,
+            arg_synopsis='TYPE SYSTEM LOCATION [KEY=VALUE]')
+        self.other = \
+            morphlib.plugins.branch_and_merge_plugin.BranchAndMergePlugin()
+        self.other.app = self.app
+
+    def disable(self):
+        pass
+
+    def deploy(self, args):
+        '''Deploy a built system image.'''
+
+        if len(args) < 3:
+            raise cliapp.AppException(
+                'Too few arguments to deploy command (see help)')
+
+        deployment_type = args[0]
+        system_name = args[1]
+        location = args[2]
+        env_vars = args[3:]
+
+        # Deduce workspace and system branch and branch root repository.
+        workspace = self.other.deduce_workspace()
+        branch, branch_dir = self.other.deduce_system_branch()
+        branch_root = self.other.get_branch_config(branch_dir, 'branch.root')
+        branch_uuid = self.other.get_branch_config(branch_dir, 'branch.uuid')
+
+        # Generate a UUID for the build.
+        build_uuid = uuid.uuid4().hex
+
+        build_command = morphlib.buildcommand.BuildCommand(self.app)
+        build_command = self.app.hookmgr.call('new-build-command',
+                                              build_command)
+        push = self.app.settings['push-build-branches']
+
+        self.app.status(msg='Starting build %(uuid)s', uuid=build_uuid)
+
+        self.app.status(msg='Collecting morphologies involved in '
+                            'building %(system)s from %(branch)s',
+                            system=system_name, branch=branch)
+
+        # Get repositories of morphologies involved in building this system
+        # from the current system branch.
+        build_repos = self.other.get_system_build_repos(
+                branch, branch_dir, branch_root, system_name)
+
+        # Generate temporary build ref names for all these repositories.
+        self.other.generate_build_ref_names(build_repos, branch_uuid)
+
+        # Create the build refs for all these repositories and commit
+        # all uncommitted changes to them, updating all references
+        # to system branch refs to point to the build refs instead.
+        self.other.update_build_refs(build_repos, branch, build_uuid, push)
+
+        if push:
+            self.other.push_build_refs(build_repos)
+            build_branch_root = branch_root
+        else:
+            dirname = build_repos[branch_root]['dirname']
+            build_branch_root = urlparse.urljoin('file://', dirname)
+
+        # Run the build.
+        build_ref = build_repos[branch_root]['build-ref']
+        order = build_command.compute_build_order(
+            build_branch_root,
+            build_ref,
+            system_name + '.morph')
+        artifact = order.groups[-1][-1]
+
+        if push:
+            self.other.delete_remote_build_refs(build_repos)
+            
+        # Unpack the artifact (tarball) to a temporary directory.
+        self.app.status(msg='Unpacking system for configuration')
+
+        system_tree = tempfile.mkdtemp()
+            
+        if build_command.lac.has(artifact):
+            f = build_command.lac.get(artifact)
+        else:
+            f = build_command.rac.get(artifact)
+        ff = gzip.GzipFile(fileobj=f)
+        tf = tarfile.TarFile(fileobj=ff)
+        tf.extractall(path=system_tree)
+        
+        self.app.status(
+            msg='System unpacked at %(system_tree)s',
+            system_tree=system_tree)
+
+        # Set up environment for running extensions.
+        env = dict(os.environ)
+        for spec in env_vars:
+            name, value = spec.split('=', 1)
+            if name in env:
+                raise morphlib.Error(
+                    '%s is already set in the enviroment' % name)
+            env[name] = value
+
+        # Run configuration extensions.
+        self.app.status(msg='Configure system')
+        names = artifact.source.morphology['configuration-extensions']
+        for name in names:
+            self._run_extension(
+                branch_dir,
+                build_ref,
+                name,
+                '.configure',
+                [system_tree],
+                env)
+        
+        # Run write extension.
+        self.app.status(msg='Writing to device')
+        self._run_extension(
+            branch_dir,
+            build_ref,
+            deployment_type,
+            '.write',
+            [system_tree, location],
+            env)
+        
+        # Cleanup.
+        self.app.status(msg='Cleaning up')
+        shutil.rmtree(system_tree)
+
+        self.app.status(msg='Finished deployment')
+
+    def _run_extension(self, repo_dir, ref, name, kind, args, env):
+        '''Run an extension.
+        
+        The ``kind`` should be either ``.configure`` or ``.write``,
+        depending on the kind of extension that is sought.
+        
+        The extension is found either in the git repository of the
+        system morphology (repo, ref), or with the Morph code.
+        
+        '''
+        
+        # Look for extension in the system morphology's repository.
+        ext = self._cat_file(repo_dir, ref, name + kind)
+        if ext is None:
+            # Not found: look for it in the Morph code.
+            code_dir = os.path.dirname(morphlib.__file__)
+            ext_filename = os.path.join(code_dir, 'exts', name + kind)
+            if not os.path.exists(ext_filename):
+                raise morphlib.Error(
+                    'Could not find extension %s%s' % (name, kind))
+            delete_ext = False
+        else:
+            # Found it in the system morphology's repository.
+            fd, ext_filename = tempfile.mkstemp()
+            os.write(fd, ext)
+            os.close(fd)
+            os.chmod(ext_filename, 0700)
+            delete_ext = True
+
+        self.app.runcmd(
+            [ext_filename] + args, env=env, stdout=None, stderr=None)
+        
+        if delete_ext:
+            os.remove(ext_filename)
+        
+    def _cat_file(self, repo_dir, ref, pathname):
+        '''Retrieve contents of a file from a git repository.'''
+        
+        argv = ['git', 'cat-file', 'blob', '%s:%s' % (ref, pathname)]
+        try:
+            return self.app.runcmd(argv, cwd=repo_dir)
+        except cliapp.AppException:
+            return None
+
diff --git a/morphlib/writeexts.py b/morphlib/writeexts.py
new file mode 100755
index 00000000..60848345
--- /dev/null
+++ b/morphlib/writeexts.py
@@ -0,0 +1,185 @@
+# Copyright (C) 2012-2013  Codethink Limited
+#
+# 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.
+
+
+import cliapp
+import os
+import re
+import time
+import tempfile
+
+
+class WriteExtension(cliapp.Application):
+
+    '''A base class for deployment write extensions.
+    
+    A subclass should subclass this class, and add a
+    ``process_args`` method.
+    
+    Note that it is not necessary to subclass this class for write
+    extensions. This class is here just to collect common code for
+    write extensions.
+    
+    '''
+    
+    def process_args(self, args):
+        raise NotImplementedError()
+
+    def status(self, **kwargs):
+        '''Provide status output.
+        
+        The ``msg`` keyword argument is the actual message,
+        the rest are values for fields in the message as interpolated
+        by %.
+        
+        '''
+        
+        self.output.write('%s\n' % (kwargs['msg'] % kwargs))
+    
+    def create_local_system(self, temp_root, raw_disk):
+        '''Create a raw system image locally.'''
+        
+        size = self.get_disk_size()
+        self.create_raw_disk_image(raw_disk, size)
+        try:
+            self.mkfs_btrfs(raw_disk)
+            mp = self.mount(raw_disk)
+        except BaseException:
+            sys.stderr.write('Error creating disk image')
+            os.remove(raw_disk)
+            raise
+        try:
+            self.create_factory(mp, temp_root)
+            self.create_fstab(mp)
+            self.create_factory_run(mp)
+            self.install_extlinux(mp)
+        except BaseException, e:
+            sys.stderr.write('Error creating disk image')
+            self.unmount(mp)
+            os.remove(raw_disk)
+            raise
+        else:
+            self.unmount(mp)
+
+    def get_disk_size(self):
+        '''Parse disk size from environment.'''
+        
+        size = os.environ.get('DISK_SIZE', '1G')
+        m = re.match('^(\d+)([kmgKMG]?)$', size)
+        if not m:
+            raise morphlib.Error('Cannot parse disk size %s' % size)
+
+        factors = {
+            '': 1,
+            'k': 1024,
+            'm': 1024**2,
+            'g': 1024**3,
+        }
+        factor = factors[m.group(2).lower()]
+
+        return int(m.group(1)) * factor
+
+    def create_raw_disk_image(self, filename, size):
+        '''Create a raw disk image.'''
+
+        self.status(msg='Creating empty disk image')
+        with open(filename, 'wb') as f:
+            if size > 0:
+                f.seek(size-1)
+                f.write('\0')
+
+    def mkfs_btrfs(self, location):
+        '''Create a btrfs filesystem on the disk.'''
+        self.status(msg='Creating btrfs filesystem')
+        cliapp.runcmd(['mkfs.btrfs', '-L', 'baserock', location])
+        
+    def mount(self, location):
+        '''Mount the filesystem so it can be tweaked.
+        
+        Return path to the mount point.
+        The mount point is a newly created temporary directory.
+        The caller must call self.unmount to unmount on the return value.
+        
+        '''
+
+        self.status(msg='Mounting filesystem')        
+        tempdir = tempfile.mkdtemp()
+        cliapp.runcmd(['mount', '-o', 'loop', location, tempdir])
+        return tempdir
+        
+    def unmount(self, mount_point):
+        '''Unmount the filesystem mounted by self.mount.
+        
+        Also, remove the temporary directory.
+        
+        '''
+        
+        self.status(msg='Unmounting filesystem')
+        cliapp.runcmd(['umount', mount_point])
+        os.rmdir(mount_point)
+
+    def create_factory(self, real_root, temp_root):
+        '''Create the default "factory" system.'''
+
+        factory = os.path.join(real_root, 'factory')
+
+        self.status(msg='Creating factory subvolume')
+        cliapp.runcmd(['btrfs', 'subvolume', 'create', factory])
+        self.status(msg='Copying files to factory subvolume')
+        cliapp.runcmd(['cp', '-a', temp_root + '/.', factory + '/.'])
+
+        # The kernel needs to be on the root volume.
+        self.status(msg='Copying boot directory to root subvolume')
+        factory_boot = os.path.join(factory, 'boot')
+        root_boot = os.path.join(real_root, 'boot')
+        cliapp.runcmd(['cp', '-a', factory_boot, root_boot])
+        
+    def create_factory_run(self, real_root):
+        '''Create the 'factory-run' snapshot.'''
+
+        self.status(msg='Creating factory-run subvolume')
+        factory = os.path.join(real_root, 'factory')
+        factory_run = factory + '-run'
+        cliapp.runcmd(
+            ['btrfs', 'subvolume', 'snapshot', factory, factory_run])
+
+    def create_fstab(self, real_root):
+        '''Create an fstab.'''
+
+        self.status(msg='Creating fstab')        
+        fstab = os.path.join(real_root, 'factory', 'etc', 'fstab')
+        with open(fstab, 'w') as f:
+            f.write('/dev/sda  /     btrfs defaults,rw,noatime 0 1\n')
+
+    def install_extlinux(self, real_root):
+        '''Install extlinux on the newly created disk image.'''
+
+        self.status(msg='Creating extlinux.conf')
+        config = os.path.join(real_root, 'extlinux.conf')
+        with open(config, 'w') as f:
+            f.write('default linux\n')
+            f.write('timeout 1\n')
+            f.write('label linux\n')
+            f.write('kernel /boot/vmlinuz\n')
+            f.write('append root=/dev/sda rootflags=subvol=factory-run '
+                    'init=/sbin/init rw\n')
+
+        self.status(msg='Installing extlinux')
+        cliapp.runcmd(['extlinux', '--install', real_root])
+
+        # FIXME this hack seems to be necessary to let extlinux finish
+        cliapp.runcmd(['sync'])
+        time.sleep(2)
+