Merge pull request #57 from blueboxgroup/builder-drivers

Add ability to extend builders via builder drivers

CHANGELOG.md

@@ -0,0 +1,3 @@
+2.1.0
+-----
+- feature: add builder drivers using stevedore

giftwrap/builders/__init__.py

@@ -19,9 +19,12 @@ import os
 import threading
 
 from giftwrap.gerrit import GerritReview
+from stevedore.driver import DriverManager
+from stevedore.extension import ExtensionManager
 
 from abc import abstractmethod, ABCMeta
 
+BUILDER_DRIVER_NAMESPACE = 'giftwrap.builder.drivers'
 LOG = logging.getLogger(__name__)
 
 
@@ -34,6 +37,12 @@ class Builder(object):
         self._spec = spec
         self._thread_exit = []
 
+    @staticmethod
+    def builder_names(ext_mgr=None):
+        if not ext_mgr:
+            ext_mgr = ExtensionManager(BUILDER_DRIVER_NAMESPACE)
+        return ext_mgr.names()
+
     def _get_venv_pip_path(self, venv_path):
         return os.path.join(venv_path, 'bin/pip')
 
@@ -182,5 +191,8 @@ class BuilderFactory:
 
     @staticmethod
     def create_builder(builder_type, build_spec):
-        targetclass = "%sBuilder" % builder_type.capitalize()
-        return globals()[targetclass](build_spec)
+        driver_mgr = DriverManager(namespace=BUILDER_DRIVER_NAMESPACE,
+                                   name=builder_type,
+                                   invoke_args=(build_spec,),
+                                   invoke_on_load=True)
+        return driver_mgr.driver

giftwrap/shell.py

@@ -19,7 +19,7 @@ import logging
 import signal
 import sys
 
-from giftwrap.builders import BuilderFactory
+from giftwrap.builders import Builder, BuilderFactory
 from giftwrap.build_spec import BuildSpec
 from giftwrap.color import ColorStreamHandler
 
@@ -80,7 +80,7 @@ def main():
                                          description='build giftwrap packages')
     build_subcmd.add_argument('-m', '--manifest', required=True)
     build_subcmd.add_argument('-v', '--version')
-    build_subcmd.add_argument('-t', '--type', choices=('docker', 'package'),
+    build_subcmd.add_argument('-t', '--type', choices=Builder.builder_names(),
                               required=True)
     build_subcmd.add_argument('-s', '--synchronous', dest='parallel',
                               action='store_false')

giftwrap/tests/test_builder.py

@@ -0,0 +1,39 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2015, Craig Tracey
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import copy
+import unittest2 as unittest
+
+from giftwrap.builders import Builder, BUILDER_DRIVER_NAMESPACE
+from stevedore import extension
+
+BASE_DRIVERS = set(['docker', 'package'])
+
+
+class TestBuilder(unittest.TestCase):
+
+    def test_default_drivers(self):
+        drivers = set(Builder.builder_names())
+        self.assertEqual(drivers, BASE_DRIVERS)
+
+    def test_additional_drivers(self):
+        em = extension.ExtensionManager(BUILDER_DRIVER_NAMESPACE)
+        em.extensions.append(extension.Extension('test', None, None, None))
+        drivers = set(Builder.builder_names(em))
+        base_drivers = copy.copy(BASE_DRIVERS)
+        base_drivers.add('test')
+        self.assertEqual(drivers, base_drivers)

requirements.txt

@@ -9,3 +9,4 @@ requests
 pygerrit
 docker-py
 virtualenv
+stevedore

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = giftwrap
-version = 2.0.0
+version = 2.1.0
 summary = giftwrap - A tool to build full-stack native system packages.
 description-file =
     README.md
@@ -23,6 +23,10 @@ setup-hooks =
 console_scripts =
     giftwrap = giftwrap.shell:main
 
+giftwrap.builder.drivers =
+    package = giftwrap.builders.package_builder:PackageBuilder
+    docker = giftwrap.builders.docker_builder:DockerBuilder
+
 [files]
 packages =
     giftwrap