Add an API example base and functional test base

Add examples/common.py, which is a basic common setup that mimics OSC's
configuration options and logging without the rest of the CLI.

Also add the functional test tooling for examples to prevent bit rot.

Co-Authored-By: Dean Troyer <dtroyer@gmail.com>
Change-Id: Ie92b675eafd93482ddc9a8ce0b0588e23ed50c35

1 files changed, 264 insertions, 0 deletions

diff --git a/examples/common.py b/examples/common.py
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+#!/usr/bin/env python
+# common.py - Common bits for API examples
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""
+API Examples
+
+This is a collection of common functions used by the example scripts.
+It may also be run directly as a script to do basic testing of itself.
+
+common.object_parser() provides the common set of command-line arguments
+used in the library CLIs for setting up authentication.  This should make
+playing with the example scripts against a running OpenStack simpler.
+
+common.configure_logging() provides the same basic logging control as
+the OSC shell.
+
+common.make_session() does the minimal loading of a Keystone authentication
+plugin and creates a Keystone client Session.
+
+"""
+
+import argparse
+import logging
+import os
+import sys
+import traceback
+
+from keystoneclient import session as ksc_session
+
+from openstackclient.api import auth
+
+
+CONSOLE_MESSAGE_FORMAT = '%(levelname)s: %(name)s %(message)s'
+DEFAULT_VERBOSE_LEVEL = 1
+USER_AGENT = 'osc-examples'
+
+PARSER_DESCRIPTION = 'A demonstration framework'
+
+DEFAULT_IDENTITY_API_VERSION = '2.0'
+
+_logger = logging.getLogger(__name__)
+
+# --debug sets this True
+dump_stack_trace = False
+
+
+# Generally useful stuff often found in a utils module
+
+def env(*vars, **kwargs):
+    """Search for the first defined of possibly many env vars
+
+    Returns the first environment variable defined in vars, or
+    returns the default defined in kwargs.
+
+    """
+    for v in vars:
+        value = os.environ.get(v, None)
+        if value:
+            return value
+    return kwargs.get('default', '')
+
+
+# Common Example functions
+
+def base_parser(parser):
+    """Set up some of the common CLI options
+
+    These are the basic options that match the library CLIs so
+    command-line/environment setups for those also work with these
+    demonstration programs.
+
+    """
+
+    # Global arguments
+    parser.add_argument(
+        '--os-url',
+        metavar='<url>',
+        default=env('OS_URL'),
+        help='Defaults to env[OS_URL]',
+    )
+    parser.add_argument(
+        '--os-region-name',
+        metavar='<auth-region-name>',
+        default=env('OS_REGION_NAME'),
+        help='Authentication region name (Env: OS_REGION_NAME)',
+    )
+    parser.add_argument(
+        '--os-cacert',
+        metavar='<ca-bundle-file>',
+        default=env('OS_CACERT'),
+        help='CA certificate bundle file (Env: OS_CACERT)',
+    )
+    verify_group = parser.add_mutually_exclusive_group()
+    verify_group.add_argument(
+        '--verify',
+        action='store_true',
+        help='Verify server certificate (default)',
+    )
+    verify_group.add_argument(
+        '--insecure',
+        action='store_true',
+        help='Disable server certificate verification',
+    )
+    parser.add_argument(
+        '--timing',
+        default=False,
+        action='store_true',
+        help="Print API call timing info",
+    )
+    parser.add_argument(
+        '-v', '--verbose',
+        action='count',
+        dest='verbose_level',
+        default=1,
+        help='Increase verbosity of output. Can be repeated.',
+    )
+    parser.add_argument(
+        '--debug',
+        default=False,
+        action='store_true',
+        help='show tracebacks on errors',
+    )
+    parser.add_argument(
+        'rest',
+        nargs='*',
+        help='the rest of the args',
+    )
+    return parser
+
+
+def configure_logging(opts):
+    """Typical app logging setup
+
+    Based on OSC/cliff
+
+    """
+
+    global dump_stack_trace
+
+    root_logger = logging.getLogger('')
+
+    # Requests logs some stuff at INFO that we don't want
+    # unless we have DEBUG
+    requests_log = logging.getLogger("requests")
+    requests_log.setLevel(logging.ERROR)
+
+    # Other modules we don't want DEBUG output for so
+    # don't reset them below
+    iso8601_log = logging.getLogger("iso8601")
+    iso8601_log.setLevel(logging.ERROR)
+
+    # Always send higher-level messages to the console via stderr
+    console = logging.StreamHandler(sys.stderr)
+    formatter = logging.Formatter(CONSOLE_MESSAGE_FORMAT)
+    console.setFormatter(formatter)
+    root_logger.addHandler(console)
+
+    # Set logging to the requested level
+    dump_stack_trace = False
+    if opts.verbose_level == 0:
+        # --quiet
+        root_logger.setLevel(logging.ERROR)
+    elif opts.verbose_level == 1:
+        # This is the default case, no --debug, --verbose or --quiet
+        root_logger.setLevel(logging.WARNING)
+    elif opts.verbose_level == 2:
+        # One --verbose
+        root_logger.setLevel(logging.INFO)
+    elif opts.verbose_level >= 3:
+        # Two or more --verbose
+        root_logger.setLevel(logging.DEBUG)
+        requests_log.setLevel(logging.DEBUG)
+
+    if opts.debug:
+        # --debug forces traceback
+        dump_stack_trace = True
+        root_logger.setLevel(logging.DEBUG)
+        requests_log.setLevel(logging.DEBUG)
+
+    return
+
+
+def make_session(opts, **kwargs):
+    """Create our base session using simple auth from ksc plugins
+
+    The arguments required in opts varies depending on the auth plugin
+    that is used.  This example assumes Identity v2 will be used
+    and selects token auth if both os_url and os_token have been
+    provided, otherwise it uses password.
+
+    :param Namespace opts:
+        A parser options Namespace containing the authentication
+        options to be used
+    :param dict kwargs:
+        Additional options passed directly to Session constructor
+    """
+
+    # If no auth type is named by the user, select one based on
+    # the supplied options
+    auth_plugin_name = auth.select_auth_plugin(opts)
+
+    (auth_plugin, auth_params) = auth.build_auth_params(
+        auth_plugin_name,
+        opts,
+    )
+    auth_p = auth_plugin.load_from_options(**auth_params)
+
+    session = ksc_session.Session(
+        auth=auth_p,
+        **kwargs
+    )
+
+    return session
+
+
+# Top-level functions
+
+def run(opts):
+    """Default run command"""
+
+    # Do some basic testing here
+    sys.stdout.write("Default run command\n")
+    sys.stdout.write("Verbose level: %s\n" % opts.verbose_level)
+    sys.stdout.write("Debug: %s\n" % opts.debug)
+    sys.stdout.write("dump_stack_trace: %s\n" % dump_stack_trace)
+
+
+def setup():
+    """Parse command line and configure logging"""
+    opts = base_parser(
+        auth.build_auth_plugins_option_parser(
+            argparse.ArgumentParser(description='Object API Example')
+        )
+    ).parse_args()
+    configure_logging(opts)
+    return opts
+
+
+def main(opts, run):
+    try:
+        return run(opts)
+    except Exception as e:
+        if dump_stack_trace:
+            _logger.error(traceback.format_exc(e))
+        else:
+            _logger.error('Exception raised: ' + str(e))
+        return 1
+
+
+if __name__ == "__main__":
+    opts = setup()
+    sys.exit(main(opts, run))