Use oslo.config for CLI arguments

It seems weird to import oslo.config then use argparse to parse CLI
arguments. Let's leverage our common libraries.

I couldn't find a way to accept "-vvv" in oslo.config neatly, so I've
changed 'verbose' to an IntOpt and updated autohelp-wrapper. I did
look at adding this to oslo.config but exceeded the time I wanted to
spend.

Change-Id: I4e02257571f3349d492dfdd56a5746d1fa2ae9dd

autogenerate_config_docs/autohelp-wrapper

@@ -121,9 +121,9 @@ while getopts :b:g:e:v:cfq opt; do
         QUIET=1
         ;;
     v)
-        AUTOOPT="-v"
+        AUTOOPT="-v 1"
         if [ $OPTARG = 2 ]; then
-            AUTOOPT="-vv"
+            AUTOOPT="-v 2"
         fi
         ;;
     \?)

autogenerate_config_docs/autohelp.py

@@ -17,19 +17,18 @@
 # For an example of usage, run this program with the -h switch.
 #
 
-# Must import this before argparse
-from oslo_config import cfg
 
-import argparse
 import importlib
 import os
 import pickle
 import re
 import sys
 
-import jinja2
+from oslo_config import cfg
 import stevedore
 
+import jinja2
+
 try:
     from sqlalchemy import exc
 except Exception:
@@ -41,6 +40,29 @@ try:
 except ImportError:
     pass
 
+_conf_description = 'Manage flag files, to aid in updating documentation.'
+_opts = [
+    cfg.StrOpt('subcommand',
+               required=True,
+               choices=['update', 'rst', 'dump'],
+               help='Action (update, rst, dump).'),
+    cfg.StrOpt('package',
+               required=True,
+               help='Name of the top-level package.'),
+    cfg.IntOpt('verbose', short='v',
+               default=0),
+    cfg.MultiStrOpt('input', short='i',
+                    required=True,
+                    dest='repos',
+                    help='Path to a python package in which options should '
+                         'be discovered. Can be used multiple times.',
+                    ),
+    cfg.StrOpt('output', short='o',
+               dest='target',
+               help='Directory or file in which data will be saved.\n'
+                    'Defaults to ../../doc/common/tables/ for "rst".\n'
+                    'Defaults to stdout for "dump"'),
+]
 
 EXTENSIONS = ['oslo.cache',
               'oslo.concurrency',
@@ -565,41 +587,14 @@ def update_flagmappings(package_name, options, verbose=0):
 
 
 def main():
-    parser = argparse.ArgumentParser(
-        description='Manage flag files, to aid in updating documentation.',
-        usage='%(prog)s <cmd> <package> [options]')
-    parser.add_argument('subcommand',
-                        help='Action (update, rst, dump).',
-                        choices=['update', 'rst', 'dump'])
-    parser.add_argument('package',
-                        help='Name of the top-level package.')
-    parser.add_argument('-v', '--verbose',
-                        action='count',
-                        default=0,
-                        dest='verbose',
-                        required=False,)
-    parser.add_argument('-i', '--input',
-                        dest='repos',
-                        help='Path to a python package in which options '
-                             'should be discoverd. Can be used multiple '
-                             'times.',
-                        required=False,
-                        type=str,
-                        action='append')
-    parser.add_argument('-o', '--output',
-                        dest='target',
-                        help='Directory or file in which data will be saved.\n'
-                             'Defaults to ../../doc/common/tables/ '
-                             'for "rst".\n'
-                             'Defaults to stdout for "dump"',
-                        required=False,
-                        type=str,)
-    args = parser.parse_args()
+    conf = cfg.ConfigOpts()
+    conf.register_cli_opts(_opts)
+    conf(sys.argv[1:], description=_conf_description)
 
-    if args.repos is None:
-        args.repos = ['./sources/%s/%s' % args.package]
+    if conf.repos is None:
+        conf.repos = ['./sources/%s/%s' % conf.package]
 
-    for repository in args.repos:
+    for repository in conf.repos:
         package_name = os.path.basename(repository)
         base_path = os.path.dirname(repository)
 
@@ -607,28 +602,28 @@ def main():
         try:
             __import__(package_name)
         except ImportError as e:
-            if args.verbose >= 1:
+            if conf.verbose >= 1:
                 print(str(e))
                 print("Failed to import: %s (%s)" % (package_name, e))
 
-        import_modules(base_path, package_name, verbose=args.verbose)
+        import_modules(base_path, package_name, verbose=conf.verbose)
         sys.path.pop(0)
 
     overrides = _get_overrides(package_name)
-    options = OptionsCache(overrides, verbose=args.verbose)
-    options.maybe_load_extensions(args.repos)
+    options = OptionsCache(overrides, verbose=conf.verbose)
+    options.maybe_load_extensions(conf.repos)
 
-    if args.verbose > 0:
+    if conf.verbose > 0:
         print("%s options imported from package %s." % (len(options),
                                                         str(package_name)))
 
-    if args.subcommand == 'update':
-        update_flagmappings(args.package, options, verbose=args.verbose)
+    if conf.subcommand == 'update':
+        update_flagmappings(conf.package, options, verbose=conf.verbose)
 
-    elif args.subcommand == 'rst':
-        write_files(args.package, options, args.target, args.subcommand)
+    elif conf.subcommand == 'rst':
+        write_files(conf.package, options, conf.target, conf.subcommand)
 
-    elif args.subcommand == 'dump':
+    elif conf.subcommand == 'dump':
         options.dump()