update install_venv_common to handle bootstrapping

old install_venv_common used oslo-config, which makes for bad
recursive dependencies, and we can't build a venv from a fresh
tree.

Change-Id: I09336d760842d4eb57f2b70fdfe19afaf6520a48

tools/install_venv_common.py

@@ -21,18 +21,11 @@ virtual environments.
 Synced in from openstack-common
 """
 
+import argparse
 import os
 import subprocess
 import sys
 
-possible_topdir = os.getcwd()
-if os.path.exists(os.path.join(possible_topdir, "cinder",
-                               "__init__.py")):
-    sys.path.insert(0, possible_topdir)
-
-
-from oslo.config import cfg
-
 
 class InstallVenv(object):
 
@@ -57,7 +50,7 @@ class InstallVenv(object):
                               check_exit_code=True):
         """Runs a command in an out-of-process shell.
 
-        Returns the output of that command. Working directory is ROOT.
+        Returns the output of that command. Working directory is self.root.
         """
         if redirect_output:
             stdout = subprocess.PIPE
@@ -100,7 +93,7 @@ class InstallVenv(object):
             else:
                 self.run_command(['virtualenv', '-q', self.venv])
             print 'done.'
-            print 'Installing pip in virtualenv...',
+            print 'Installing pip in venv...',
             if not self.run_command(['tools/with_venv.sh', 'easy_install',
                                     'pip>1.0']).strip():
                 self.die("Failed to install pip.")
@@ -138,17 +131,12 @@ class InstallVenv(object):
 
     def parse_args(self, argv):
         """Parses command-line arguments."""
-        cli_opts = [
-            cfg.BoolOpt('no-site-packages',
-                        default=False,
-                        short='n',
-                        help="Do not inherit packages from global Python"
-                             "install"),
-        ]
-        CLI = cfg.ConfigOpts()
-        CLI.register_cli_opts(cli_opts)
-        CLI(argv[1:])
-        return CLI
+        parser = argparse.ArgumentParser()
+        parser.add_argument('-n', '--no-site-packages',
+                            action='store_true',
+                            help="Do not inherit packages from global Python "
+                                 "install")
+        return parser.parse_args(argv[1:])
 
 
 class Distro(InstallVenv):