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

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

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"""
 

openstackclient/shell.py

@@ -140,12 +140,11 @@ class OpenStackShell(shell.OpenStackShell):
         # First, throw away what has already been done with o-c-c and
         # use our own.
         try:
-            cc = cloud_config.OSC_Config(
+            self.cloud_config = cloud_config.OSC_Config(
                 override_defaults={
                     'interface': None,
                     'auth_type': self._auth_type,
                 },
-                pw_func=shell.prompt_for_password,
             )
         except (IOError, OSError) as e:
             self.log.critical("Could not read clouds.yaml configuration file")
@@ -154,9 +153,13 @@ class OpenStackShell(shell.OpenStackShell):
 
         if not self.options.debug:
             self.options.debug = None
-        self.cloud = cc.get_one_cloud(
+
+        # NOTE(dtroyer): Need to do this with validate=False to defer the
+        #                auth plugin handling to ClientManager.setup_auth()
+        self.cloud = self.cloud_config.get_one_cloud(
             cloud=self.options.cloud,
             argparse=self.options,
+            validate=False,
         )
 
         # Then, re-create the client_manager with the correct arguments
@@ -165,6 +168,33 @@ class OpenStackShell(shell.OpenStackShell):
             api_version=self.api_version,
         )
 
+    def prepare_to_run_command(self, cmd):
+        """Set up auth and API versions"""
+
+        # TODO(dtroyer): Move this to osc-lib
+        # NOTE(dtroyer): If auth is not required for a command, force fake
+        #                token auth so KSA plugins are happy
+
+        kwargs = {}
+        if not cmd.auth_required:
+            # Build fake token creds to keep ksa and o-c-c hushed
+            kwargs['auth_type'] = 'token_endpoint'
+            kwargs['auth'] = {}
+            kwargs['auth']['token'] = 'x'
+            kwargs['auth']['url'] = 'x'
+
+        # Validate auth options
+        self.cloud = self.cloud_config.get_one_cloud(
+            cloud=self.options.cloud,
+            argparse=self.options,
+            validate=True,
+            **kwargs
+        )
+        # Push the updated args into ClientManager
+        self.client_manager._cli_options = self.cloud
+
+        return super(OpenStackShell, self).prepare_to_run_command(cmd)
+
 
 def main(argv=None):
     if argv is None: