don't install packages if you don't want to (--keep_packages)

devstack/opts.py

@@ -69,6 +69,10 @@ def parse():
         dest="r_component",
         metavar="COMPONENT",
         help="component which will not have ACTION applied but will be referenced as if it was (ACTION dependent)")
+    base_group.add_option("-k", "--keep-packages",
+        action="store_true",
+        dest="keep_packages",
+        help="uninstall will keep any installed packages on the system")
     parser.add_option_group(base_group)
 
     stop_un_group = OptionGroup(parser, "Uninstall/stop options")
@@ -107,5 +111,6 @@ def parse():
         output['ignore_deps'] = False
     else:
         output['ignore_deps'] = True
+    output['keep_packages'] = options.keep_packages
     output['extras'] = args
     return output

devstack/packager.py

@@ -22,14 +22,17 @@ LOG = logging.getLogger("devstack.packager")
 
 
 class Packager(object):
-    def __init__(self, distro):
+    def __init__(self, distro, keep_packages):
         self.distro = distro
+        self.keep_packages = keep_packages
 
     def install_batch(self, pkgs):
         raise NotImplementedError()
 
     def remove_batch(self, pkgs):
-        raise NotImplementedError()
+        if not self.keep_packages:
+            return self._remove_batch(pkgs)
+        return []
 
     def pre_install(self, pkgs, installparams=None):
         pkgnames = sorted(pkgs.keys())
@@ -48,3 +51,6 @@ class Packager(object):
             if postinstallcmds and len(postinstallcmds):
                 LOG.info("Running post-install commands for package %s." % (name))
                 utils.execute_template(*postinstallcmds, params=installparams)
+
+    def _remove_batch(self, pkgs):
+        raise NotImplementedError()

devstack/packaging/apt.py

@@ -42,8 +42,8 @@ VERSION_TEMPL = "%s=%s"
 
 
 class AptPackager(pack.Packager):
-    def __init__(self, distro):
-        pack.Packager.__init__(self, distro)
+    def __init__(self, distro, keep_packages):
+        pack.Packager.__init__(self, distro, keep_packages)
         self.auto_remove = True
 
     def _format_pkg(self, name, version):
@@ -59,7 +59,7 @@ class AptPackager(pack.Packager):
             env_overrides=ENV_ADDITIONS,
             **kargs)
 
-    def remove_batch(self, pkgs):
+    def _remove_batch(self, pkgs):
         pkgnames = sorted(pkgs.keys())
         #form the needed commands
         cmds = []

devstack/packaging/yum.py

@@ -32,8 +32,8 @@ VERSION_TEMPL = "%s-%s"
 
 
 class YumPackager(pack.Packager):
-    def __init__(self, distro):
-        pack.Packager.__init__(self, distro)
+    def __init__(self, distro, keep_packages):
+        pack.Packager.__init__(self, distro, keep_packages)
 
     def _format_pkg_name(self, name, version):
         if version is not None and len(version):

devstack/progs/actions.py

@@ -135,9 +135,9 @@ def _clean_action(action):
     return action
 
 
-def _get_pkg_manager(distro):
+def _get_pkg_manager(distro, keep_packages):
     cls = _PKGR_MAP.get(distro)
-    return cls(distro)
+    return cls(distro, keep_packages)
 
 
 def _get_action_cls(action_name, component_name):
@@ -286,7 +286,7 @@ def _run_components(action_name, component_order, components, distro, root_dir,
     non_components = set(components.keys()).difference(set(component_order))
     if non_components:
         LOG.info("Using reference components [%s]" % (", ".join(sorted(non_components))))
-    pkg_manager = _get_pkg_manager(distro)
+    pkg_manager = _get_pkg_manager(distro, program_args.pop('keep_packages', True))
     config = _get_config()
     #form the active instances (this includes ones we won't use)
     all_instances = dict()