Plugin architecture working

build-debian-cloud

@@ -0,0 +1,6 @@
+#!/usr/bin/env python
+
+
+if __name__ == '__main__' and __package__ is None:
+	from common import main
+	main.main()

common/__init__.py

@@ -2,3 +2,4 @@ from bootstrapinfo import BootstrapInformation
 from manifest import Manifest
 from task import Task
 from tasklist import TaskList
+from plugin import Plugin

common/main.py

@@ -0,0 +1,31 @@
+from providers import providers
+
+
+def main():
+	from argparse import ArgumentParser
+	parser = ArgumentParser(description='Bootstrap Debian for the cloud.')
+	parser.add_argument('--debug', action='store_true',
+	                    help='Print debugging information')
+	parser.set_defaults(func=run)
+
+	subparsers = parser.add_subparsers(title='providers', description='supported providers', dest='provider')
+
+	for provider in providers.values():
+		provider.init_subparser(subparsers)
+
+	args = parser.parse_args()
+	args.func(args)
+
+
+def run(args):
+	provider = providers[args.provider]
+	manifest = provider.Manifest(args.manifest)
+	manifest.validate()
+	manifest.load_plugins()
+
+	tasklist = provider.tasklist(manifest)
+	tasklist.plugins(manifest)
+
+	from common import BootstrapInformation
+	bootstrap_info = BootstrapInformation(manifest, args)
+	tasklist.run(bootstrap_info)

common/manifest.py

@@ -9,6 +9,14 @@ class Manifest(object):
 	def parse(self, data):
 		self.volume  = data['volume']
 		self.system  = data['system']
+		self.plugins = data['plugins']
 
 	def validate(self):
 		pass
+
+	def load_plugins(self):
+		self.loaded_plugins = []
+		for modname in self.plugins.keys():
+			if self.plugins[modname]['enabled']:
+				plugin = __import__('plugins.%s' % modname, fromlist=['plugins'])
+				self.loaded_plugins.append(plugin)

common/tasklist.py

@@ -1,15 +1,24 @@
 
 
 class TaskList(list):
-	def run(self, info):
+
+	def plugins(self, manifest):
+		for plugin in manifest.loaded_plugins:
+			plugin.modify_tasklist(self, manifest)
+
+	def run(self, bootstrap_info):
 		for task in self:
-			task.run(info)
+			task.run(bootstrap_info)
 
-	def before(self, task):
-		pass
+	def before(self, ref, task):
+		i = next(i for i, task in enumerate(self) if type(task) is ref)
+		self.insert(i, task)
 
-	def replace(self, task):
-		pass
+	def replace(self, ref, task):
+		i = next(i for i, task in enumerate(self) if type(task) is ref)
+		self.pop(i)
+		self.insert(i, task)
 
-	def after(self, task):
-		pass
+	def after(self, ref, task):
+		i = next(i for i, task in enumerate(self) if type(task) is ref)
+		self.insert(i+1, task)

debian-build-cloud

@@ -1,18 +0,0 @@
-#!/usr/bin/env python
-
-
-def main():
-	from argparse import ArgumentParser
-	import ec2
-	parser = ArgumentParser(description='Bootstrap Debian for the cloud.')
-	parser.add_argument('--debug', action='store_true',
-	                    help='Print debugging information')
-
-	subparsers = parser.add_subparsers(title='providers', description='supported providers', dest='provider')
-	ec2.init_subparser(subparsers)
-
-	args = parser.parse_args()
-	args.func(args)
-
-if __name__ == '__main__' and __package__ is None:
-	main()

ec2/__init__.py

@@ -1 +0,0 @@
-from main import init_subparser

ec2/main.py

@@ -1,37 +0,0 @@
-
-
-def init_subparser(subparsers):
-	cmd = subparsers.add_parser('ec2', help='Bootstrap Debian for EC2')
-	cmd.add_argument('--access-key', help='AWS Access Key', metavar='ID')
-	cmd.add_argument('--secret-key', help='AWS Secret Key', metavar='KEY')
-	cmd.add_argument('manifest', help='Manifest file to use for bootstrapping', metavar='MANIFEST')
-	cmd.set_defaults(func=run)
-
-
-def run(args):
-	from manifest import Manifest
-	from common import BootstrapInformation
-	manifest = Manifest(args.manifest)
-	manifest.validate()
-
-	task_list = get_tasklist(manifest)
-
-	info = BootstrapInformation(manifest=manifest, args=args)
-	task_list.run(info)
-
-
-def get_tasklist(manifest):
-	from common import TaskList
-	import packages
-	import ec2
-	import host
-	task_list = TaskList()
-	task_list.extend([packages.HostPackages(),
-	                  packages.ImagePackages(),
-	                  ec2.GetCredentials(),
-	                  host.GetInfo(),
-	                  ec2.Connect(),
-	                  host.InstallPackages()
-                   ])
-
-	return task_list

manifests/ec2-ebs-pvm.manifest.json

@@ -25,11 +25,11 @@
 		"size"      : "1G"   
 	},
 	"plugins": {
-		"admin-user": {
+		"admin_user": {
 			"enabled": true
 		},
-		"build-metadata": {
-			"enabled": false,
+		"build_metadata": {
+			"enabled": true,
 			"path"   : "/root/build-metadata-{ami_name}"
 		}
 	}

plugins/admin_user/__init__.py

@@ -0,0 +1,6 @@
+
+
+def modify_tasklist(tasklist, manifest):
+	from providers.ec2.packages import ImagePackages
+	from adminuser import AddSudoPackage
+	tasklist.after(ImagePackages, AddSudoPackage())

plugins/admin_user/adminuser.py

@@ -0,0 +1,7 @@
+from common import Task
+
+
+class AddSudoPackage(Task):
+	def run(self, info):
+		super(AddSudoPackage, self).run(info)
+		info.img_packages[0].add('sudo')

plugins/build_metadata/__init__.py

@@ -0,0 +1,5 @@
+
+
+def modify_tasklist(tasklist, manifest):
+	from buildmetadata import PrintInfo
+	tasklist.append(PrintInfo())

plugins/build_metadata/buildmetadata.py

@@ -0,0 +1,7 @@
+from common import Task
+
+
+class PrintInfo(Task):
+	def run(self, info):
+		super(PrintInfo, self).run(info)
+		print('info')

providers/__init__.py

@@ -0,0 +1,4 @@
+import ec2
+
+
+providers = {'ec2': ec2}

providers/ec2/__init__.py

@@ -0,0 +1,25 @@
+from manifest import Manifest
+
+
+def init_subparser(subparsers):
+	sub = subparsers.add_parser('ec2', help='Bootstrap Debian for EC2')
+	sub.add_argument('--access-key', help='AWS Access Key', metavar='ID')
+	sub.add_argument('--secret-key', help='AWS Secret Key', metavar='KEY')
+	sub.add_argument('manifest', help='Manifest file to use for bootstrapping', metavar='MANIFEST')
+
+
+def tasklist(manifest):
+	from common import TaskList
+	import packages
+	import ec2
+	import host
+	task_list = TaskList()
+	task_list.extend([packages.HostPackages(),
+	                  packages.ImagePackages(),
+	                  ec2.GetCredentials(),
+	                  host.GetInfo(),
+	                  ec2.Connect(),
+	                  host.InstallPackages()
+                   ])
+
+	return task_list

providers/ec2/ec2.py

@@ -5,7 +5,6 @@ class GetCredentials(Task):
 	def run(self, info):
 		super(GetCredentials, self).run(info)
 		info.ec2_credentials = self.get_ec2_credentials(info.args, info.manifest)
-		return info
 
 	def get_ec2_credentials(self, args, manifest):
 		from os import getenv
@@ -37,4 +36,4 @@ class Connect(Task):
 		# info.ec2_connection = boto.ec2.connect_to_region(info.host['region'],
 		#                                                  aws_access_key_id=info.ec2_credentials['access_key'],
 		#                                                  aws_secret_access_key=info.ec2_credentials['secret_key'])
-		return info
+		# return 'ec2_connection', ec2_connection

providers/ec2/host.py

@@ -4,13 +4,15 @@ from common import Task
 class GetInfo(Task):
 	def run(self, info):
 		super(GetInfo, self).run(info)
-		import urllib2
-		import json
+		# import urllib2
+		# import json
 		# response = urllib2.urlopen('http://169.254.169.254/latest/dynamic/instance-identity/document')
 		# info.host = json.load(response.read())
-		return info
+		# return info
 
 
 class InstallPackages(Task):
 	def run(self, info):
+		# Check if packages are installed with
+		# /usr/bin/dpkg -s ${name} | grep -q 'Status: install'
 		pass

providers/ec2/packages.py

@@ -4,27 +4,20 @@ from common import Task
 class HostPackages(Task):
 	def run(self, info):
 		super(HostPackages, self).run(info)
-		info.host_pkg = self.get_host_packages(info.manifest)
-		return info
-
-	def get_host_packages(self, manifest):
 		packages = set(['debootstrap',
 		                # To make sure a volume is not busy before unmounting we need lsof
 		                'lsof',
 		                ])
-		if manifest.volume['filesystem'] == 'xfs':
+		if info.manifest.volume['filesystem'] == 'xfs':
 			packages.add('xfsprogs')
 
-		return packages
+		info.host_packages = packages
 
 
 class ImagePackages(Task):
 	def run(self, info):
 		super(ImagePackages, self).run(info)
-		info.image_pkg_include, info.image_pkg_exclude = self.get_image_packages(info.manifest)
-		return info
-
-	def get_image_packages(self, manifest):
+		manifest = info.manifest
 		# Add some basic packages we are going to need
 		include = set(['udev',
 		               'openssh-server',
@@ -52,4 +45,4 @@ class ImagePackages(Task):
 		
 		include = include.union(manifest.system['packages'])
 		
-		return include, exclude
+		info.img_packages = include, exclude