Override endpoint URL check for API version

get_volume_api_version_from_endpoint currently assumes that the
management_url will always be in the format of
http://<ip>:<port>/vX/<tenant_id>. Customers using a gateway, however,
can get a mangement_url in a different form like
https://<ip>:<port>/<resource>/vX/<tenant_id>.  This causes the
get_volume_api_version_from_endpoint to find the resource portion of the
url when looking for the Volume API version which makes the
cinder client unusable.

To resolve this I have implemented an exception handler in the case that
get_volume_api_version_from_endpoint fails.  If the exception is thrown, I
check for OS_VOLUME_API_VERSION in the environment and use the value of that
environment variable, if it is set, to determine the API version to use.

There are proposals to fix this via changes to keystone in future releases,
but this provides a way for IaaS Gateway users to proceed with Havana.

Change-Id: I8b978a6ecd87b81c6ae34938e37623ad1cc33994
Closes-Bug: 1233311

cinderclient/shell.py

@@ -1,5 +1,5 @@
 
-# Copyright (c) 2011 OpenStack Foundation
+# Copyright 2011 OpenStack LLC.
 # All Rights Reserved.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -41,6 +41,7 @@ DEFAULT_OS_VOLUME_API_VERSION = "1"
 DEFAULT_CINDER_ENDPOINT_TYPE = 'publicURL'
 DEFAULT_CINDER_SERVICE_TYPE = 'volume'
 
+logging.basicConfig()
 logger = logging.getLogger(__name__)
 
 
@@ -173,7 +174,7 @@ class OpenStackCinderShell(object):
         parser.add_argument('--os-volume-api-version',
                             metavar='<volume-api-ver>',
                             default=utils.env('OS_VOLUME_API_VERSION',
-                            default=DEFAULT_OS_VOLUME_API_VERSION),
+                            default=None),
                             help='Accepts 1 or 2,defaults '
                                  'to env[OS_VOLUME_API_VERSION].')
         parser.add_argument('--os_volume_api_version',
@@ -327,7 +328,7 @@ class OpenStackCinderShell(object):
         streamhandler = logging.StreamHandler()
         streamformat = "%(levelname)s (%(module)s:%(lineno)d) %(message)s"
         streamhandler.setFormatter(logging.Formatter(streamformat))
-        logger.setLevel(logging.DEBUG)
+        logger.setLevel(logging.WARNING)
         logger.addHandler(streamhandler)
 
     def main(self, argv):
@@ -335,6 +336,14 @@ class OpenStackCinderShell(object):
         parser = self.get_base_parser()
         (options, args) = parser.parse_known_args(argv)
         self.setup_debugging(options.debug)
+        api_version_input = True
+
+        if not options.os_volume_api_version:
+            # Environment variable OS_VOLUME_API_VERSION was
+            # not set and '--os-volume-api-version' option doesn't
+            # specify a value.  Fall back to default.
+            options.os_volume_api_version = DEFAULT_OS_VOLUME_API_VERSION
+            api_version_input = False
 
         # build available subcommands based on version
         self.extensions = self._discover_extensions(
@@ -450,14 +459,33 @@ class OpenStackCinderShell(object):
         except exc.AuthorizationFailure:
             raise exc.CommandError("Unable to authorize user")
 
-        endpoint_api_version = self.cs.get_volume_api_version_from_endpoint()
-        if endpoint_api_version != options.os_volume_api_version:
-            msg = (("Volume API version is set to %s "
-                    "but you are accessing a %s endpoint. "
-                    "Change its value via either --os-volume-api-version "
-                    "or env[OS_VOLUME_API_VERSION]")
-                   % (options.os_volume_api_version, endpoint_api_version))
-            raise exc.InvalidAPIVersion(msg)
+        endpoint_api_version = None
+        # Try to get the API version from the endpoint URL.  If that fails fall
+        # back to trying to use what the user specified via
+        # --os-volume-api-version or with the OS_VOLUME_API_VERSION environment
+        # variable.  Fail safe is to use the default API setting.
+        try:
+            endpoint_api_version = \
+                self.cs.get_volume_api_version_from_endpoint()
+            if endpoint_api_version != options.os_volume_api_version:
+                msg = (("Volume API version is set to %s "
+                        "but you are accessing a %s endpoint. "
+                        "Change its value via either --os-volume-api-version "
+                        "or env[OS_VOLUME_API_VERSION]")
+                       % (options.os_volume_api_version, endpoint_api_version))
+                raise exc.InvalidAPIVersion(msg)
+        except exc.UnsupportedVersion:
+            endpoint_api_version = options.os_volume_api_version
+            if api_version_input:
+                logger.warning("Unable to determine the API version via "
+                               "endpoint URL.  Falling back to user "
+                               "specified version: %s" %
+                               endpoint_api_version)
+            else:
+                logger.warning("Unable to determine the API version from "
+                               "endpoint URL or user input.  Falling back to "
+                               "default API version: %s" %
+                               endpoint_api_version)
 
         args.func(self.cs, args)