Move package-specific logic into custom package manager classes

and allow the distro file to specify when to use them. There
are two examples, one for Rabbit on Oneiric and another more general
for managing symlinks needed after installing a package with
Yum.

conf/distros/rhel-6.yaml

@@ -2,6 +2,7 @@
 # RedHat Enterprise Linux 6
 name: rhel-6
 distro_pattern: redhat-6(.*)
+packager_name: devstack.packaging.yum:YumPackager
 commands:
     apache:
         restart: service httpd restart
@@ -250,6 +251,12 @@ components:
             name: python-webob1.0
             removable: true
             version: 1.0*
+            packager_name: devstack.distros.rhel6:YumPackagerWithRelinks
+            packager_options:
+                links:
+                    - source: /usr/lib/python2.6/site-packages/WebOb-1.0.8-py2.6.egg/webob/
+                      target: /usr/lib/python2.6/site-packages/webob
+
         pips:
         -   name: CherryPy
             version: 3.2.2
@@ -659,6 +666,5 @@ components:
             start: devstack.components.swift:SwiftRuntime
             stop: devstack.components.swift:SwiftRuntime
             uninstall: devstack.components.swift:SwiftUninstaller
-packager_name: devstack.distros.rhel6:YumPackager
 ...
 

conf/distros/ubuntu-oneiric.yaml

@@ -2,7 +2,7 @@
 # Ubuntu 11 (Oneiric)
 distro_pattern: Ubuntu(.*)oneiric
 name: ubuntu-oneiric
-packager_name: devstack.distros.oneiric:AptPackager
+packager_name: devstack.packaging.apt:AptPackager
 commands:
     apache:
         restart: service apache2 restart
@@ -617,6 +617,7 @@ components:
         -   name: rabbitmq-server
             removable: true
             version: 2.5*
+            packager_name: devstack.distros.oneiric:RabbitPackager
     swift:
         action_classes:
             install: devstack.components.swift:SwiftInstaller

devstack/component.py

@@ -128,14 +128,21 @@ class ComponentBase(object):
 
 
 class PackageBasedComponentMixin(object):
+    """Mix this into classes that need to manipulate
+    OS-level packages.
+    """
+    PACKAGER_KEY_NAME = 'packager_name'
+
     def __init__(self):
         self.default_packager = self.distro.get_default_package_manager()
 
     def get_packager(self, pkg_info):
-        if 'packager' in pkg_info:
+        if self.PACKAGER_KEY_NAME in pkg_info:
-            packager_name = pkg_info['packager']
+            packager_name = pkg_info[self.PACKAGER_KEY_NAME]
+            LOG.debug('Loading custom package manager %s', packager_name)
             packager = importer.import_entry_point(packager_name)(self.distro)
         else:
+            LOG.debug('Using default package manager')
             packager = self.default_packager
         return packager
 
@@ -199,8 +206,10 @@ class PkgInstallComponent(ComponentBase, PackageBasedComponentMixin):
         for name in self.desired_subsystems:
             if name in self.subsystem_info:
                 # Todo handle duplicates/version differences?
-                LOG.debug("Extending package list with packages for subsystem %s" % (name))
+                LOG.debug(
-                subsystem_pkgs = self.subsystem_info[name].get('packages', list())
+                    "Extending package list with packages for subsystem %s",
+                    name)
+                subsystem_pkgs = self.subsystem_info[name].get('packages', [])
                 pkg_list.extend(subsystem_pkgs)
         return pkg_list
 
@@ -210,7 +219,8 @@ class PkgInstallComponent(ComponentBase, PackageBasedComponentMixin):
         pkgs = self._get_packages()
         if pkgs:
             pkg_names = set([p['name'] for p in pkgs])
-            LOG.info("Setting up %s packages (%s)" % (len(pkg_names), ", ".join(pkg_names)))
+            LOG.info("Setting up %s packages (%s)",
+                     len(pkg_names), ", ".join(pkg_names))
             with utils.progress_bar(INSTALL_TITLE, len(pkgs)) as p_bar:
                 for (i, p) in enumerate(pkgs):
                     self.tracewriter.package_installed(p)

devstack/distros/oneiric.py

@@ -46,14 +46,14 @@ class DBInstaller(db.DBInstaller):
             sh.write_file('/etc/mysql/my.cnf', fc)
 
 
-class AptPackager(apt.AptPackager):
+class RabbitPackager(apt.AptPackager):
 
-    def _remove_special(self, name, info):
+    def _remove(self, pkg):
-        if name == 'rabbitmq-server':
         #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878597
         #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878600
+        name = pkg['name']
         LOG.debug("Handling special remove of %s." % (name))
-            pkg_full = self._format_pkg_name(name, info.get("version"))
+        pkg_full = self._format_pkg_name(name, pkg.get("version"))
         cmd = apt.APT_REMOVE + [pkg_full]
         self._execute_apt(cmd)
         #probably useful to do this
@@ -62,17 +62,14 @@ class AptPackager(apt.AptPackager):
         cmd = apt.APT_PURGE + [pkg_full]
         self._execute_apt(cmd)
         return True
-        return False
 
-    def _install_special(self, name, info):
+    def install(self, pkg):
-        if name == 'rabbitmq-server':
         #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878597
         #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878600
+        name = pkg['name']
         LOG.debug("Handling special install of %s." % (name))
         #this seems to be a temporary fix for that bug
         with tempfile.TemporaryFile() as f:
-                pkg_full = self._format_pkg_name(name, info.get("version"))
+            pkg_full = self._format_pkg_name(name, pkg.get("version"))
             cmd = apt.APT_INSTALL + [pkg_full]
             self._execute_apt(cmd, stdout_fh=f, stderr_fh=f)
-                return True
-        return False

devstack/distros/rhel6.py

@@ -33,18 +33,6 @@ LOG = logging.getLogger(__name__)
 SOCKET_CONF = "/etc/httpd/conf.d/wsgi-socket-prefix.conf"
 HTTPD_CONF = '/etc/httpd/conf/httpd.conf'
 
-# Need to relink for rhel (not a bug!)
-RHEL_RELINKS = {
-    'python-webob1.0': (
-        '/usr/lib/python2.6/site-packages/WebOb-1.0.8-py2.6.egg/webob/',
-        '/usr/lib/python2.6/site-packages/webob'
-    ),
-    'python-nose1.1': (
-        '/usr/lib/python2.6/site-packages/nose-1.1.2-py2.6.egg/nose/',
-        '/usr/lib/python2.6/site-packages/nose',
-    )
-}
-
 # See: http://wiki.libvirt.org/page/SSHPolicyKitSetup
 # FIXME: take from distro config??
 LIBVIRT_POLICY_FN = "/etc/polkit-1/localauthority/50-local.d/50-libvirt-access.pkla"
@@ -116,23 +104,23 @@ class NovaInstaller(nova.NovaInstaller):
         return configs_made
 
 
-class YumPackager(yum.YumPackager):
+class YumPackagerWithRelinks(yum.YumPackager):
 
-    def _remove_special(self, name, info):
+    def _remove(self, pkg):
-        if name in RHEL_RELINKS:
+        response = yum.YumPackager._remove(self, pkg)
-            # Note: we don't return true here so that
+        if response:
-            # the normal package cleanup happens...
+            options = pkg.get('packager_options', {})
-            (_, tgt) = RHEL_RELINKS.get(name)
+            links = options.get('links', [])
+            for src, tgt in links:
                 if sh.islink(tgt):
                     sh.unlink(tgt)
-        return False
+        return response
 
-    def _install_special(self, name, info):
+    def install(self, pkg):
-        if name in RHEL_RELINKS:
+        yum.YumPackager.install(self, pkg)
-            full_pkg_name = self._format_pkg_name(name, info.get("version"))
+        options = pkg.get('packager_options', {})
-            install_cmd = yum.YUM_INSTALL + [full_pkg_name]
+        links = options.get('links', [])
-            self._execute_yum(install_cmd)
+        for src, tgt in links:
-            (src, tgt) = RHEL_RELINKS.get(name)
             if not sh.islink(tgt):
                 # This is actually a feature, EPEL must not conflict
                 # with RHEL, so X pkg installs newer version in
@@ -142,5 +130,3 @@ class YumPackager(yum.YumPackager):
                 # like devstack does....
                 sh.symlink(src, tgt)
         return True
-        else:
-            return False

devstack/packaging/apt.py

@@ -60,8 +60,6 @@ class AptPackager(pack.Packager):
 
     def _remove(self, pkg):
         name = pkg['name']
-        if self._remove_special(name, pkg):
-            return True
         pkg_full = self._format_pkg_name(name, pkg.get("version"))
         cmd = APT_DO_REMOVE + [pkg_full]
         self._execute_apt(cmd)
@@ -71,15 +69,6 @@ class AptPackager(pack.Packager):
 
     def install(self, pkg):
         name = pkg['name']
-        if self._install_special(name, pkg):
-            return
-        else:
         pkg_full = self._format_pkg_name(name, pkg.get("version"))
         cmd = APT_INSTALL + [pkg_full]
         self._execute_apt(cmd)
-
-    def _remove_special(self, name, info):
-        return False
-
-    def _install_special(self, name, info):
-        return False