Implement partition mounts.

This solves quite a few challenges with mounting directories into root etc.

base/fs/partitions/abstract.py

@@ -1,4 +1,5 @@
 from abc import ABCMeta
+import os.path
 from common.tools import log_check_call
 from common.fsm_proxy import FSMProxy
 
@@ -13,10 +14,32 @@ class AbstractPartition(FSMProxy):
 	          {'name': 'unmount', 'src': 'mounted', 'dst': 'formatted'},
 	          ]
 
+	class Mount(object):
+		def __init__(self, source, destination, opts):
+			self.source      = source
+			self.destination = destination
+			self.opts        = opts
+
+		def mount(self, prefix):
+			mount_dir = os.path.join(prefix, self.destination)
+			if isinstance(self.source, AbstractPartition):
+				self.source.mount(mount_dir)
+			else:
+				log_check_call(['/bin/mount'] + self.opts + [self.source, mount_dir])
+			self.mount_dir = mount_dir
+
+		def unmount(self):
+			if isinstance(self.source, AbstractPartition):
+				self.source.unmount()
+			else:
+				log_check_call(['/bin/umount', self.mount_dir])
+			del self.mount_dir
+
 	def __init__(self, size, filesystem):
 		self.size          = size
 		self.filesystem    = filesystem
 		self.device_path   = None
+		self.mounts        = {}
 
 		cfg = {'initial': 'nonexistent', 'events': self.events, 'callbacks': {}}
 		super(AbstractPartition, self).__init__(cfg)
@@ -36,6 +59,23 @@ class AbstractPartition(FSMProxy):
 		log_check_call(['/bin/mount', '--types', self.filesystem, self.device_path, e.destination])
 		self.mount_dir = e.destination
 
+	def _after_mount(self, e):
+		for destination in sorted(self.mounts.iterkeys(), key=len):
+			self.mounts[destination].mount(self.mount_dir)
+
 	def _before_unmount(self, e):
+		for destination in sorted(self.mounts.iterkeys(), key=len, reverse=True):
+			self.mounts[destination].unmount()
 		log_check_call(['/bin/umount', self.mount_dir])
 		del self.mount_dir
+
+	def add_mount(self, source, destination, opts=[]):
+		mount = self.Mount(source, destination, opts)
+		if self.fsm.current == 'mounted':
+			mount.mount(self.mount_dir)
+		self.mounts[destination] = mount
+
+	def remove_mount(self, destination):
+		if self.fsm.current == 'mounted':
+			self.mounts[destination].unmount()
+		del self.mounts[destination]

base/fs/volume.py

@@ -17,7 +17,6 @@ class Volume(FSMProxy):
 
 	def __init__(self, partition_map):
 		self.device_path = None
-		self.specials_mounted = False
 		self.partition_map = partition_map
 		self.size = self.partition_map.get_total_size()
 
@@ -34,31 +33,6 @@ class Volume(FSMProxy):
 		if isinstance(self.partition_map, NoPartitions):
 			self.partition_map.root.create()
 
-	def can_mount_specials(self):
-		return self.fsm.current == 'attached'
-
-	def mount_specials(self):
-		if self.specials_mounted:
-			raise VolumeError('The special devices are already mounted')
-		root = self.partition_map.root.mount_dir
-		log_check_call(['/bin/mount', '--bind', '/dev', '{root}/dev'.format(root=root)])
-		log_check_call(['/usr/sbin/chroot', root, '/bin/mount', '--types', 'proc', 'none', '/proc'])
-		log_check_call(['/usr/sbin/chroot', root, '/bin/mount', '--types', 'sysfs', 'none', '/sys'])
-		log_check_call(['/usr/sbin/chroot', root, '/bin/mount', '--types', 'devpts', 'none', '/dev/pts'])
-		self.specials_mounted = True
-
-	def unmount_specials(self):
-		if not self.specials_mounted:
-			raise VolumeError('The special devices are not mounted')
-		root = self.partition_map.root.mount_dir
-		log_check_call(['/usr/sbin/chroot', root, '/bin/umount', '/dev/pts'])
-		log_check_call(['/usr/sbin/chroot', root, '/bin/umount', '/sys'])
-		log_check_call(['/usr/sbin/chroot', root, '/bin/umount', '/proc'])
-		log_check_call(['/bin/umount', '{root}/dev'.format(root=root)])
-		self.specials_mounted = False
-
 	def _check_blocking(self, e):
 		if self.partition_map.is_blocking():
 			raise VolumeError('The partitionmap prevents the detach procedure')
-		if self.specials_mounted:
-			raise VolumeError('The special devices are mounted and prevent the detaching procedure')

common/fs/__init__.py

@@ -20,10 +20,6 @@ def remount(volume, fn):
 	from base.fs.partitionmaps.none import NoPartitions
 
 	p_map = volume.partition_map
-	volume.unmount_specials()
-	if hasattr(p_map, 'boot'):
-		boot_dir = p_map.boot.mount_dir
-		p_map.boot.unmount()
 	root_dir = p_map.root.mount_dir
 	p_map.root.unmount()
 	if not isinstance(p_map, NoPartitions):
@@ -33,7 +29,4 @@ def remount(volume, fn):
 	else:
 		result = fn()
 	p_map.root.mount(root_dir)
-	if hasattr(p_map, 'boot'):
-		p_map.boot.mount(boot_dir)
-	volume.mount_specials()
 	return result

common/fs/loopbackvolume.py

@@ -19,9 +19,6 @@ class LoopbackVolume(Volume):
 
 	extension = 'raw'
 
-	def can_mount_specials(self):
-		return self.fsm.current in ['attached', 'linked']
-
 	def create(self, image_path):
 		self.fsm.create(image_path=image_path)
 

common/task_sets.py

@@ -31,13 +31,11 @@ partitioning_set = [partitioning.PartitionVolume,
 
 boot_partition_set = [filesystem.CreateBootMountDir,
                       filesystem.MountBoot,
-                      filesystem.UnmountBoot,
                       ]
 
 mounting_set = [filesystem.CreateMountDir,
                 filesystem.MountRoot,
                 filesystem.MountSpecials,
-                filesystem.UnmountSpecials,
                 filesystem.UnmountRoot,
                 filesystem.DeleteMountDir,
                 ]

common/tasks/filesystem.py

@@ -55,25 +55,24 @@ class MountRoot(Task):
 		info.volume.partition_map.root.mount(info.root)
 
 
-class MountBoot(Task):
-	description = 'Mounting the boot partition'
-	phase = phases.volume_mounting
-	predecessors = [MountRoot]
-
-	def run(self, info):
-		info.volume.partition_map.boot.mount(info.boot_dir)
-
-
 class CreateBootMountDir(Task):
 	description = 'Creating mountpoint for the boot partition'
 	phase = phases.volume_mounting
-	successors = [MountBoot]
 	predecessors = [MountRoot]
 
 	def run(self, info):
-		import os
-		info.boot_dir = os.path.join(info.root, 'boot')
-		os.makedirs(info.boot_dir)
+		import os.path
+		os.makedirs(os.path.join(info.root, 'boot'))
+
+
+class MountBoot(Task):
+	description = 'Mounting the boot partition'
+	phase = phases.volume_mounting
+	predecessors = [CreateBootMountDir]
+
+	def run(self, info):
+		p_map = info.volume.partition_map
+		p_map.root.add_mount(p_map.boot, 'boot')
 
 
 class MountSpecials(Task):
@@ -82,7 +81,11 @@ class MountSpecials(Task):
 	predecessors = [Bootstrap]
 
 	def run(self, info):
-		info.volume.mount_specials()
+		root = info.volume.partition_map.root
+		root.add_mount('/dev', 'dev', ['--bind'])
+		root.add_mount('none', 'proc', ['--types', 'proc'])
+		root.add_mount('none', 'sys', ['--types', 'sysfs'])
+		root.add_mount('none', 'dev/pts', ['--types', 'devpts'])
 
 
 class UnmountRoot(Task):
@@ -94,24 +97,6 @@ class UnmountRoot(Task):
 		info.volume.partition_map.root.unmount()
 
 
-class UnmountBoot(Task):
-	description = 'Unmounting the boot partition'
-	phase = phases.volume_unmounting
-	successors = [UnmountRoot]
-
-	def run(self, info):
-		info.volume.partition_map.boot.unmount()
-
-
-class UnmountSpecials(Task):
-	description = 'Unmunting special block devices'
-	phase = phases.volume_unmounting
-	successors = [UnmountRoot]
-
-	def run(self, info):
-		info.volume.unmount_specials()
-
-
 class DeleteMountDir(Task):
 	description = 'Deleting mountpoint for the bootstrap volume'
 	phase = phases.volume_unmounting

manifests/virtualbox.manifest.json

@@ -1,18 +1,18 @@
 {
-	"provider"      : "virtualbox",
+	"provider": "virtualbox",
 	"bootstrapper": {
 		"workspace": "/target"
 	},
 	"image": {
-		"name"       : "debian-{release}-{architecture}-{%y}{%m}{%d}",
+		"name":        "debian-{release}-{architecture}-{%y}{%m}{%d}",
 		"description": "Debian {release} {architecture}"
 	},
 	"system": {
-		"release"     : "wheezy",
+		"release":      "wheezy",
 		"architecture": "amd64",
-		"timezone"    : "UTC",
-		"locale"      : "en_US",
-		"charmap"     : "UTF-8"
+		"timezone":     "UTC",
+		"locale":       "en_US",
+		"charmap":      "UTF-8"
 	},
 	"volume": {
 		"backing": "vdi",

plugins/prebootstrapped/__init__.py

@@ -2,7 +2,6 @@ from tasks import Snapshot
 from tasks import CopyImage
 from tasks import CreateFromSnapshot
 from tasks import CreateFromImage
-from tasks import SetBootMountDir
 from providers.ec2.tasks import ebs
 from common.tasks import loopback
 from common.tasks import volume
@@ -27,16 +26,12 @@ def tasks(tasklist, manifest):
 		if 'snapshot' in settings and settings['snapshot'] is not None:
 			tasklist.add(CreateFromSnapshot)
 			tasklist.remove(*skip_tasks)
-			if 'boot' in manifest.volume['partitions']:
-				tasklist.add(SetBootMountDir)
 		else:
 			tasklist.add(Snapshot)
 	else:
 		if 'image' in settings and settings['image'] is not None:
 			tasklist.add(CreateFromImage)
 			tasklist.remove(*skip_tasks)
-			if 'boot' in manifest.volume['partitions']:
-				tasklist.add(SetBootMountDir)
 		else:
 			tasklist.add(CopyImage)
 

plugins/prebootstrapped/tasks.py

@@ -14,7 +14,7 @@ log = logging.getLogger(__name__)
 class Snapshot(Task):
 	description = 'Creating a snapshot of the bootstrapped volume'
 	phase = phases.os_installation
-	predecessors = [bootstrap.Bootstrap, filesystem.MountSpecials]
+	predecessors = [bootstrap.Bootstrap]
 
 	def run(self, info):
 		def mk_snapshot():
@@ -45,7 +45,7 @@ class CreateFromSnapshot(Task):
 class CopyImage(Task):
 	description = 'Creating a snapshot of the bootstrapped volume'
 	phase = phases.os_installation
-	predecessors = [bootstrap.Bootstrap, filesystem.MountSpecials]
+	predecessors = [bootstrap.Bootstrap]
 
 	def run(self, info):
 		loopback_backup_name = 'volume-{id:x}.{ext}.backup'.format(id=info.run_id, ext=info.volume.extension)
@@ -71,16 +71,6 @@ class CreateFromImage(Task):
 		set_fs_states(info.volume)
 
 
-class SetBootMountDir(Task):
-	description = 'Setting mountpoint for the boot partition'
-	phase = phases.volume_mounting
-	predecessors = [filesystem.MountRoot]
-	successors = [filesystem.MountBoot]
-
-	def run(self, info):
-		info.boot_dir = os.path.join(info.root, 'boot')
-
-
 def set_fs_states(volume):
 		volume.fsm.current = 'detached'
 

providers/ec2/__init__.py

@@ -107,10 +107,8 @@ def rollback_tasks(tasklist, tasks_completed, manifest):
 
 	counter_task(partitioning.MapPartitions, partitioning.UnmapPartitions)
 	counter_task(common_filesystem.CreateMountDir, common_filesystem.DeleteMountDir)
-	counter_task(common_filesystem.MountSpecials, common_filesystem.UnmountSpecials)
 
 	counter_task(common_filesystem.MountRoot, common_filesystem.UnmountRoot)
-	counter_task(common_filesystem.MountBoot, common_filesystem.UnmountBoot)
 	counter_task(volume_tasks.Attach, volume_tasks.Detach)
 	counter_task(workspace.CreateWorkspace, workspace.DeleteWorkspace)
 	counter_task(ami.BundleImage, ami.RemoveBundle)

providers/virtualbox/__init__.py

@@ -74,7 +74,5 @@ def rollback_tasks(tasklist, tasks_completed, manifest):
 	counter_task(filesystem.CreateMountDir, filesystem.DeleteMountDir)
 	counter_task(partitioning.MapPartitions, partitioning.UnmapPartitions)
 	counter_task(filesystem.MountRoot, filesystem.UnmountRoot)
-	counter_task(filesystem.MountBoot, filesystem.UnmountBoot)
-	counter_task(filesystem.MountSpecials, filesystem.UnmountSpecials)
 	counter_task(volume_tasks.Attach, volume_tasks.Detach)
 	counter_task(workspace.CreateWorkspace, workspace.DeleteWorkspace)