Add references instead of instances to the tasklist

base/task.py

@@ -1,4 +1,3 @@
-from common.exceptions import TaskListError
 
 
 class Task(object):
@@ -6,27 +5,8 @@ class Task(object):
 	before = []
 	after = []
 
-	def __init__(self):
-		self._check_ordering()
-
 	def __str__(self):
 		return '{module}.{task}'.format(module=self.__module__, task=self.__class__.__name__)
 
 	def __repr__(self):
 		return self.__str__()
-
-	def _check_ordering(self):
-		def name(ref):
-			return '{module}.{task}'.format(module=ref.__module__, task=ref.__class__.__name__)
-		for task in self.before:
-			if self.phase > task.phase:
-				msg = ("The task {self} is specified as running before {other}, "
-				       "but its phase '{phase}' lies after the phase '{other_phase}'"
-				       .format(self=type(self), other=task, phase=self.phase, other_phase=task.phase))
-				raise TaskListError(msg)
-		for task in self.after:
-			if self.phase < task.phase:
-				msg = ("The task {self} is specified as running after {other}, "
-				       "but its phase '{phase}' lies before the phase '{other_phase}'"
-				       .format(self=type(self), other=task, phase=self.phase, other_phase=task.phase))
-				raise TaskListError(msg)

base/tasklist.py

@@ -13,23 +13,19 @@ class TaskList(object):
 		self.tasks.update(args)
 
 	def remove(self, *args):
-		for task_type in args:
+		for task in args:
-			task = self.get(task_type)
+			self.tasks.discard(task)
-			if task is not None:
-				self.tasks.discard(task)
 
 	def replace(self, task, replacement):
 		self.remove(task)
 		self.add(replacement)
 
-	def get(self, ref):
-		return next((task for task in self.tasks if type(task) is ref), None)
-
 	def run(self, bootstrap_info):
 		task_list = self.create_list(self.tasks)
 		log.debug('Tasklist:\n\t{list}'.format(list='\n\t'.join(repr(task) for task in task_list)))
 
-		for task in task_list:
+		for task_type in task_list:
+			task = task_type()
 			if hasattr(task, 'description'):
 				log.info(task.description)
 			else:
@@ -41,12 +37,13 @@ class TaskList(object):
 		from common.phases import order
 		graph = {}
 		for task in tasks:
-			successors = []
+			self.check_ordering(task)
-			successors.extend([self.get(succ) for succ in task.before])
+			successors = set()
-			successors.extend(filter(lambda succ: type(task) in succ.after, tasks))
+			successors.update(task.before)
+			successors.update(filter(lambda succ: task in succ.after, tasks))
 			succeeding_phases = order[order.index(task.phase) + 1:]
-			successors.extend(filter(lambda succ: succ.phase in succeeding_phases, tasks))
+			successors.update(filter(lambda succ: succ.phase in succeeding_phases, tasks))
-			graph[task] = filter(lambda succ: succ in self.tasks, successors)
+			graph[task] = filter(lambda succ: succ in tasks, successors)
 
 		components = self.strongly_connected_components(graph)
 		cycles_found = 0
@@ -63,6 +60,20 @@ class TaskList(object):
 
 		return sorted_tasks
 
+	def check_ordering(self, task):
+		for successor in task.before:
+			if successor.phase > successor.phase:
+				msg = ("The task {task} is specified as running before {other}, "
+				       "but its phase '{phase}' lies after the phase '{other_phase}'"
+				       .format(task=task, other=successor, phase=task.phase, other_phase=successor.phase))
+				raise TaskListError(msg)
+		for predecessor in task.after:
+			if task.phase < predecessor.phase:
+				msg = ("The task {task} is specified as running after {other}, "
+				       "but its phase '{phase}' lies before the phase '{other_phase}'"
+				       .format(task=task, other=predecessor, phase=task.phase, other_phase=predecessor.phase))
+				raise TaskListError(msg)
+
 	def strongly_connected_components(self, graph):
 		# Source: http://www.logarithmic.net/pfh-files/blog/01208083168/sort.py
 		# Find the strongly connected components in a graph using Tarjan's algorithm.

plugins/admin_user/__init__.py

@@ -2,11 +2,11 @@
 
 def tasks(tasklist, manifest):
 	import tasks
-	tasklist.add(tasks.AddSudoPackage())
+	tasklist.add(tasks.AddSudoPackage.
-	tasklist.add(tasks.CreateAdminUser())
+	             tasks.CreateAdminUser,
-	tasklist.add(tasks.PasswordlessSudo())
+	             tasks.PasswordlessSudo,
-	tasklist.add(tasks.AdminUserCredentials())
+	             tasks.AdminUserCredentials,
-	tasklist.add(tasks.DisableRootLogin())
+	             tasks.DisableRootLogin)
 
 
 def validate_manifest(data, schema_validate):

plugins/backports/__init__.py

@@ -2,8 +2,8 @@
 
 def tasks(tasklist, manifest):
 	import tasks
-	tasklist.add(tasks.AptSourcesBackports())
+	tasklist.add(tasks.AptSourcesBackports,
-	tasklist.add(tasks.AddBackportsPackages())
+	             tasks.AddBackportsPackages)
 
 
 def validate_manifest(data, schema_validate):

plugins/build_metadata/__init__.py

@@ -2,4 +2,4 @@
 
 def tasks(tasklist, manifest):
 	from tasks import WriteMetadata
-	tasklist.add(WriteMetadata())
+	tasklist.add(WriteMetadata

plugins/convert_image/__init__.py

@@ -2,7 +2,7 @@
 
 def tasks(tasklist, manifest):
 	from tasks import ConvertImage
-	tasklist.add(ConvertImage())
+	tasklist.add(ConvertImage)
 
 
 def validate_manifest(data, schema_validate):

plugins/opennebula/__init__.py

@@ -2,4 +2,4 @@
 
 def tasks(tasklist, manifest):
 	import tasks
-	tasklist.add(tasks.OpenNebulaContext())
+	tasklist.add(tasks.OpenNebulaContext)

plugins/prebootstrapped/__init__.py

@@ -21,16 +21,16 @@ def tasks(tasklist, manifest):
 	              bootstrap.Bootstrap]
 	if manifest.volume['backing'] == 'ebs':
 		if 'snapshot' in settings and settings['snapshot'] is not None:
-			tasklist.replace(ebs.Create, CreateFromSnapshot())
+			tasklist.replace(ebs.Create, CreateFromSnapshot)
 			tasklist.remove(*skip_tasks)
 		else:
-			tasklist.add(Snapshot())
+			tasklist.add(Snapshot)
 	else:
 		if 'image' in settings and settings['image'] is not None:
-			tasklist.replace(loopback.Create, CreateFromImage())
+			tasklist.replace(loopback.Create, CreateFromImage)
 			tasklist.remove(*skip_tasks)
 		else:
-			tasklist.add(CopyImage())
+			tasklist.add(CopyImage)
 
 
 def rollback_tasks(tasklist, tasks_completed, manifest):
@@ -38,7 +38,7 @@ def rollback_tasks(tasklist, tasks_completed, manifest):
 
 	def counter_task(task, counter):
 		if task in completed and counter not in completed:
-			tasklist.add(counter())
+			tasklist.add(counter)
 
 	if manifest.volume['backing'] == 'ebs':
 		counter_task(CreateFromSnapshot, volume.Delete)

plugins/root_password/__init__.py

@@ -3,7 +3,7 @@
 def tasks(tasklist, manifest):
 	from common.tasks.security import DisableSSHPasswordAuthentication
 	from tasks import SetRootPassword
-	tasklist.replace(DisableSSHPasswordAuthentication, SetRootPassword())
+	tasklist.replace(DisableSSHPasswordAuthentication, SetRootPassword)
 
 
 def validate_manifest(data, schema_validate):

plugins/unattended_upgrades/__init__.py

@@ -2,8 +2,8 @@
 
 def tasks(tasklist, manifest):
 	import tasks
-	tasklist.add(tasks.AddUnattendedUpgradesPackage())
+	tasklist.add(tasks.AddUnattendedUpgradesPackage,
-	tasklist.add(tasks.EnablePeriodicUpgrades())
+	             tasks.EnablePeriodicUpgrades)
 
 
 def validate_manifest(data, schema_validate):

plugins/user_packages/__init__.py

@@ -2,5 +2,5 @@
 
 def tasks(tasklist, manifest):
 	from user_packages import AddUserPackages, AddLocalUserPackages
-	tasklist.add(AddUserPackages())
+	tasklist.add(AddUserPackages,
-	tasklist.add(AddLocalUserPackages())
+	             AddLocalUserPackages)

providers/virtualbox/__init__.py

@@ -23,54 +23,54 @@ def initialize():
 
 
 def tasks(tasklist, manifest):
-	tasklist.add(workspace.CreateWorkspace(),
+	tasklist.add(workspace.CreateWorkspace,
-	             packages.HostPackages(),
+	             packages.HostPackages,
-	             common_packages.HostPackages(),
+	             common_packages.HostPackages,
-	             packages.ImagePackages(),
+	             packages.ImagePackages,
-	             common_packages.ImagePackages(),
+	             common_packages.ImagePackages,
-	             host.CheckPackages(),
+	             host.CheckPackages,
 
-	             loopback.Create(),
+	             loopback.Create,
-	             volume_tasks.Attach(),
+	             volume_tasks.Attach,
-	             partitioning.PartitionVolume(),
+	             partitioning.PartitionVolume,
-	             partitioning.MapPartitions(),
+	             partitioning.MapPartitions,
-	             filesystem.Format(),
+	             filesystem.Format,
-	             filesystem.CreateMountDir(),
+	             filesystem.CreateMountDir,
-	             filesystem.MountRoot(),
+	             filesystem.MountRoot,
 
-	             bootstrap.Bootstrap(),
+	             bootstrap.Bootstrap,
-	             filesystem.MountSpecials(),
+	             filesystem.MountSpecials,
-	             locale.GenerateLocale(),
+	             locale.GenerateLocale,
-	             locale.SetTimezone(),
+	             locale.SetTimezone,
-	             apt.DisableDaemonAutostart(),
+	             apt.DisableDaemonAutostart,
-	             apt.AptSources(),
+	             apt.AptSources,
-	             apt.AptUpgrade(),
+	             apt.AptUpgrade,
-	             boot.ConfigureGrub(),
+	             boot.ConfigureGrub,
-	             filesystem.FStab(),
+	             filesystem.FStab,
-	             common_boot.BlackListModules(),
+	             common_boot.BlackListModules,
-	             common_boot.DisableGetTTYs(),
+	             common_boot.DisableGetTTYs,
-	             security.EnableShadowConfig(),
+	             security.EnableShadowConfig,
-	             network.RemoveDNSInfo(),
+	             network.RemoveDNSInfo,
-	             network.ConfigureNetworkIF(),
+	             network.ConfigureNetworkIF,
-	             network.RemoveHostname(),
+	             network.RemoveHostname,
-	             initd.ResolveInitScripts(),
+	             initd.ResolveInitScripts,
-	             initd.InstallInitScripts(),
+	             initd.InstallInitScripts,
-	             cleanup.ClearMOTD(),
+	             cleanup.ClearMOTD,
-	             cleanup.CleanTMP(),
+	             cleanup.CleanTMP,
-	             apt.PurgeUnusedPackages(),
+	             apt.PurgeUnusedPackages,
-	             apt.AptClean(),
+	             apt.AptClean,
-	             apt.EnableDaemonAutostart(),
+	             apt.EnableDaemonAutostart,
-	             filesystem.UnmountSpecials(),
+	             filesystem.UnmountSpecials,
 
-	             filesystem.UnmountRoot(),
+	             filesystem.UnmountRoot,
-	             partitioning.UnmapPartitions(),
+	             partitioning.UnmapPartitions,
-	             volume_tasks.Detach(),
+	             volume_tasks.Detach,
-	             filesystem.DeleteMountDir(),
+	             filesystem.DeleteMountDir,
-	             loopback.MoveImage(),
+	             loopback.MoveImage,
-	             workspace.DeleteWorkspace())
+	             workspace.DeleteWorkspace)
 
 	if manifest.bootstrapper.get('tarball', False):
-		tasklist.add(bootstrap.MakeTarball())
+		tasklist.add(bootstrap.MakeTarball)
 
 	partitions = manifest.volume['partitions']
 	import re
@@ -78,19 +78,19 @@ def tasks(tasklist, manifest):
 		if key not in partitions:
 			continue
 		if re.match('^ext[2-4]$', partitions[key]['filesystem']) is not None:
-			tasklist.add(filesystem.TuneVolumeFS())
+			tasklist.add(filesystem.TuneVolumeFS)
 			break
 	for key in ['boot', 'root']:
 		if key not in partitions:
 			continue
 		if partitions[key]['filesystem'] == 'xfs':
-			tasklist.add(filesystem.AddXFSProgs())
+			tasklist.add(filesystem.AddXFSProgs)
 			break
 
 	if 'boot' in manifest.volume['partitions']:
-		tasklist.add(filesystem.CreateBootMountDir(),
+		tasklist.add(filesystem.CreateBootMountDir,
-		             filesystem.MountBoot(),
+		             filesystem.MountBoot,
-		             filesystem.UnmountBoot())
+		             filesystem.UnmountBoot)
 
 
 def rollback_tasks(tasklist, tasks_completed, manifest):
@@ -98,7 +98,7 @@ def rollback_tasks(tasklist, tasks_completed, manifest):
 
 	def counter_task(task, counter):
 		if task in completed and counter not in completed:
-			tasklist.add(counter())
+			tasklist.add(counter)
 
 	counter_task(loopback.Create, volume_tasks.Delete)
 	counter_task(filesystem.CreateMountDir, filesystem.DeleteMountDir)