Defer auth prompting until it is actually needed

Auth option prompting happens waaaay to early in the default
os-client-config flow, we need to defer it until adter the commands
have been parsed.  This is why ClientManager.setup_auth() exists,
as it is not called until the first attempt to connect to a server
occurs.  Commands that do not require authentication never hit this.

Also, required options were not being enforced.  By doing this we handle
when no authentication info is present, we fail on missing auth-url rather
than attempt to prompt for a password (default auth is password).

Closes-Bug: 1619274
Change-Id: Ia4eae350e6904c9eb2c8507d9b3429fe52418726

2 files changed, 48 insertions, 0 deletions

diff --git a/openstackclient/common/client_config.py b/openstackclient/common/client_config.py
index 895909e9..30286df8 100644
--- a/openstackclient/common/client_config.py
+++ b/openstackclient/common/client_config.py
@@ -16,6 +16,7 @@
 import logging
 
 from os_client_config import config
+from os_client_config import exceptions as occ_exceptions
 
 
 LOG = logging.getLogger(__name__)
@@ -182,6 +183,14 @@ class OSC_Config(config.OpenStackConfig):
         LOG.debug("auth_config_hook(): %s" % config)
         return config
 
+    def load_auth_plugin(self, config):
+        """Get auth plugin and validate args"""
+
+        loader = self._get_auth_loader(config)
+        config = self._validate_auth(config, loader)
+        auth_plugin = loader.load_from_options(**config['auth'])
+        return auth_plugin
+
     def _validate_auth_ksc(self, config, cloud, fixed_argparse=None):
         """Old compatibility hack for OSC, no longer needed/wanted"""
         return config
@@ -192,6 +201,8 @@ class OSC_Config(config.OpenStackConfig):
 
         plugin_options = loader.get_options()
 
+        msgs = []
+        prompt_options = []
         for p_opt in plugin_options:
             # if it's in config, win, move it and kill it from config dict
             # if it's in config.auth but not in config we're good
@@ -202,6 +213,16 @@ class OSC_Config(config.OpenStackConfig):
                 winning_value = self._find_winning_auth_value(
                     p_opt, config['auth'])
 
+            # if the plugin tells us that this value is required
+            # then error if it's doesn't exist now
+            if not winning_value and p_opt.required:
+                msgs.append(
+                    'Missing value {auth_key}'
+                    ' required for auth plugin {plugin}'.format(
+                        auth_key=p_opt.name, plugin=config.get('auth_type'),
+                    )
+                )
+
             # Clean up after ourselves
             for opt in [p_opt.name] + [o.name for o in p_opt.deprecated]:
                 opt = opt.replace('-', '_')
@@ -224,6 +245,13 @@ class OSC_Config(config.OpenStackConfig):
                     p_opt.dest not in config['auth'] and
                     self._pw_callback is not None
             ):
+                # Defer these until we know all required opts are present
+                prompt_options.append(p_opt)
+
+        if msgs:
+            raise occ_exceptions.OpenStackConfigException('\n'.join(msgs))
+        else:
+            for p_opt in prompt_options:
                 config['auth'][p_opt.dest] = self._pw_callback(p_opt.prompt)
 
         return config
diff --git a/openstackclient/common/clientmanager.py b/openstackclient/common/clientmanager.py
index 57423aed..23c35a3b 100644
--- a/openstackclient/common/clientmanager.py
+++ b/openstackclient/common/clientmanager.py
@@ -60,6 +60,26 @@ class ClientManager(clientmanager.ClientManager):
         self._cacert = self.cacert
         self._insecure = not self.verify
 
+    def setup_auth(self):
+        """Set up authentication"""
+
+        if self._auth_setup_completed:
+            return
+
+        # NOTE(dtroyer): Validate the auth args; this is protected with 'if'
+        #                because openstack_config is an optional argument to
+        #                CloudConfig.__init__() and we'll die if it was not
+        #                passed.
+        if self._cli_options._openstack_config is not None:
+            self._cli_options._openstack_config._pw_callback = \
+                shell.prompt_for_password
+            self._cli_options._auth = \
+                self._cli_options._openstack_config.load_auth_plugin(
+                    self._cli_options.config,
+                )
+
+        return super(ClientManager, self).setup_auth()
+
     def is_network_endpoint_enabled(self):
         """Check if the network endpoint is enabled"""