CLI support of Keystone openrc

Add support of the standard openrc env vars
to the CLI so that a token will be automatically
generated and the Drydock API endpoint will be
sourced from the Keystone catalogue.

- Use click to allow env or cli based keystone env

Change-Id: I10a48d509c0b90670af07870a1ae4d31525b4a3b

drydock_provisioner/cli/commands.py

@@ -18,6 +18,7 @@ from urllib.parse import urlparse
 
 import click
 from drydock_provisioner.drydock_client.session import DrydockSession
+from drydock_provisioner.drydock_client.session import KeystoneClient
 from drydock_provisioner.drydock_client.client import DrydockClient
 from .design import commands as design
 from .part import commands as part
@@ -27,32 +28,43 @@ from .node import commands as node
 @click.group()
 @click.option(
     '--debug/--no-debug', help='Enable or disable debugging', default=False)
+# Supported Environment Variables
 @click.option(
-    '--token',
+    '--os_project_domain_name',
-    '-t',
+    envvar='OS_PROJECT_DOMAIN_NAME',
-    help='The auth token to be used',
+    required=False)
-    default=lambda: os.environ.get('DD_TOKEN', ''))
+@click.option(
+    '--os_user_domain_name', envvar='OS_USER_DOMAIN_NAME', required=False)
+@click.option('--os_project_name', envvar='OS_PROJECT_NAME', required=False)
+@click.option('--os_username', envvar='OS_USERNAME', required=False)
+@click.option('--os_password', envvar='OS_PASSWORD', required=False)
+@click.option('--os_auth_url', envvar='OS_AUTH_URL', required=False)
+@click.option(
+    '--os_token',
+    help='The Keystone token to be used',
+    default=lambda: os.environ.get('OS_TOKEN', ''))
 @click.option(
     '--url',
     '-u',
     help='The url of the running drydock instance',
     default=lambda: os.environ.get('DD_URL', ''))
 @click.pass_context
-def drydock(ctx, debug, token, url):
+def drydock(ctx, debug, url, os_project_domain_name, os_user_domain_name, os_project_name,
-    """ Drydock CLI to invoke the running instance of the drydock API
+            os_username, os_password, os_auth_url, os_token):
-    """
+    """Drydock CLI to invoke the running instance of the drydock API."""
     if not ctx.obj:
         ctx.obj = {}
 
     ctx.obj['DEBUG'] = debug
 
-    if not token:
+    keystone_env = {
-        ctx.fail('Error: Token must be specified either by '
+        'project_domain_name': os_project_domain_name,
-                 '--token or DD_TOKEN from the environment')
+        'user_domain_name': os_user_domain_name,
-
+        'project_name': os_project_name,
-    if not url:
+        'username': os_username,
-        ctx.fail('Error: URL must be specified either by '
+        'password': os_password,
-                 '--url or DD_URL from the environment')
+        'auth_url': os_auth_url,
+    }
 
     # setup logging for the CLI
     # Setup root logger
@@ -66,18 +78,44 @@ def drydock(ctx, debug, token, url):
     logger.addHandler(logging_handler)
     logger.debug('logging for cli initialized')
 
+    try:
+        if not os_token:
+            logger.debug("Generating Keystone session by env vars: %s" % str(keystone_env))
+            ks_sess = KeystoneClient.get_ks_session(**keystone_env)
+        else:
+            logger.debug("Generating Keystone session by explicit token: %s" % os_token)
+            ks_sess = KeystoneClient.get_ks_session(token=os_token)
+        KeystoneClient.get_token(ks_sess=ks_sess)
+    except Exception as ex:
+        logger.debug("Exception getting Keystone session.", exc_info=ex)
+        ctx.fail('Error: Unable to authenticate with Keystone')
+        return
+
+    try:
+        if not url:
+            url = KeystoneClient.get_endpoint('physicalprovisioner', ks_sess=ks_sess)
+    except Exception as ex:
+        logger.debug("Exception getting Drydock endpoint.", exc_info=ex)
+        ctx.fail('Error: Unable to discover Drydock API URL')
+
     # setup the drydock client using the passed parameters.
     url_parse_result = urlparse(url)
-    logger.debug(url_parse_result)
+
+    if not os_token:
+        token = KeystoneClient.get_token(ks_sess=ks_sess)
+        logger.debug("Creating Drydock client with token %s." % token)
+    else:
+        token = os_token
+
     if not url_parse_result.scheme:
         ctx.fail('URL must specify a scheme and hostname, optionally a port')
     ctx.obj['CLIENT'] = DrydockClient(
         DrydockSession(
             scheme=url_parse_result.scheme,
-            host=url_parse_result.netloc,
+            host=url_parse_result.hostname,
+            port=url_parse_result.port,
             token=token))
 
-
 drydock.add_command(design.design)
 drydock.add_command(part.part)
 drydock.add_command(task.task)

drydock_provisioner/drydock_client/session.py

@@ -14,6 +14,8 @@
 import requests
 import logging
 
+from keystoneauth1 import session
+from keystoneauth1.identity import v3
 
 class DrydockSession(object):
     """
@@ -40,7 +42,7 @@ class DrydockSession(object):
             self.base_url = "%s://%s:%s/api/" % (self.scheme, self.host,
                                                  self.port)
         else:
-            #assume default port for scheme
+            # assume default port for scheme
             self.base_url = "%s://%s/api/" % (self.scheme, self.host)
 
         self.token = token
@@ -48,7 +50,6 @@ class DrydockSession(object):
 
         self.logger = logging.getLogger(__name__)
 
-    # TODO Add keystone authentication to produce a token for this session
     def get(self, endpoint, query=None):
         """
         Send a GET request to Drydock.
@@ -85,3 +86,43 @@ class DrydockSession(object):
                 self.base_url + endpoint, params=query, json=data, timeout=10)
 
         return resp
+
+
+class KeystoneClient(object):
+
+    @staticmethod
+    def get_endpoint(endpoint, ks_sess=None, auth_info=None):
+        """
+        Wraps calls to keystone for lookup of an endpoint by service type
+        :param endpoint: The endpoint to look up
+        :param ks_sess: A keystone session to use for accessing endpoint catalogue
+        :param auth_info: Authentication info to use for building a token if a ``ks_sess`` is not specified
+        :returns: The url string of the endpoint
+        :rtype: str
+        :raises AppError: if the endpoint cannot be resolved
+        """
+        if ks_sess is None:
+            ks_sess = KeystoneClient.get_ks_session(**auth_info)
+
+        return ks_sess.get_endpoint(interface='internal', service_type=endpoint)
+
+    @staticmethod
+    def get_token(ks_sess=None, auth_info=None):
+        """
+        Returns the simple token string for a token acquired from keystone
+
+        :param ks_sess: an existing Keystone session to retrieve a token from
+        :param auth_info: dictionary of information required to generate a keystone token
+        """
+        if ks_sess is None:
+            ks_sess = KeystoneClient.get_ks_session(**auth_info)
+        return ks_sess.get_auth_headers().get('X-Auth-Token')
+
+    @staticmethod
+    def get_ks_session(**kwargs):
+        # Establishes a keystone session
+        if 'token' in kwargs:
+            auth = v3.TokenMethod(token=kwargs.get('token'))
+        else:
+            auth = v3.Password(**kwargs)
+        return session.Session(auth=auth)