path: root/resources/tools/papi/vpp_papi_provider.py

#!/usr/bin/env python2

# Copyright (c) 2019 Cisco and/or its affiliates.
# 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.

r"""CSIT PAPI Provider

TODO: Add description.

Examples:
---------

Request/reply or dump:

    vpp_papi_provider.py \
        --method request \
        --data '[{"api_name": "show_version", "api_args": {}}]'

VPP-stats:

    vpp_papi_provider.py \
        --method stats \
        --data '[["^/if", "/err/ip4-input", "/sys/node/ip4-input"], ["^/if"]]'
"""

import argparse
import binascii
import json
import os
import sys


# Client name
CLIENT_NAME = 'csit_papi'


# Sphinx creates auto-generated documentation by importing the python source
# files and collecting the docstrings from them. The NO_VPP_PAPI flag allows
# the vpp_papi_provider.py file to be importable without having to build
# the whole vpp api if the user only wishes to generate the test documentation.

try:
    do_import = False if os.getenv("NO_VPP_PAPI") == "1" else True
except KeyError:
    do_import = True

if do_import:

    # Find the directory where the modules are installed. The directory depends
    # on the OS used.
    # TODO: Find a better way to import papi modules.

    modules_path = None
    for root, dirs, files in os.walk('/usr/lib'):
        for name in files:
            if name == 'vpp_papi.py':
                modules_path = os.path.split(root)[0]
                break
    if modules_path:
        sys.path.append(modules_path)
        from vpp_papi import VPP
        from vpp_papi.vpp_stats import VPPStats
    else:
        raise RuntimeError('vpp_papi module not found')


def _convert_reply(api_r):
    """Process API reply / a part of API reply for smooth converting to
    JSON string.

    It is used only with 'request' and 'dump' methods.

    Apply binascii.hexlify() method for string values.

    TODO: Implement complex solution to process of replies.

    :param api_r: API reply.
    :type api_r: Vpp_serializer reply object (named tuple)
    :returns: Processed API reply / a part of API reply.
    :rtype: dict
    """
    unwanted_fields = ['count', 'index', 'context']

    reply_dict = dict()
    reply_key = repr(api_r).split('(')[0]
    reply_value = dict()
    for item in dir(api_r):
        if not item.startswith('_') and item not in unwanted_fields:
            reply_value[item] = getattr(api_r, item)
    reply_dict[reply_key] = reply_value
    return reply_dict


def process_json_request(args):
    """Process the request/reply and dump classes of VPP API methods.

    :param args: Command line arguments passed to VPP PAPI Provider.
    :type args: ArgumentParser
    :returns: JSON formatted string.
    :rtype: str
    :raises RuntimeError: If PAPI command error occurs.
    """

    try:
        vpp = VPP()
    except Exception as err:
        raise RuntimeError('PAPI init failed:\n{err}'.format(err=repr(err)))

    reply = list()

    json_data = json.loads(args.data)
    vpp.connect(CLIENT_NAME)
    for data in json_data:
        api_name = data['api_name']
        api_args_unicode = data['api_args']
        api_reply = dict(api_name=api_name)
        api_args = dict()
        for a_k, a_v in api_args_unicode.items():
            value = binascii.unhexlify(a_v) if isinstance(a_v, unicode) else a_v
            api_args[str(a_k)] = value if isinstance(value, int) else str(value)
        try:
            papi_fn = getattr(vpp.api, api_name)
            rep = papi_fn(**api_args)

            if isinstance(rep, list):
                converted_reply = list()
                for r in rep:
                    converted_reply.append(_convert_reply(r))
            else:
                converted_reply = _convert_reply(rep)

            api_reply['api_reply'] = converted_reply
            reply.append(api_reply)
        except (AttributeError, ValueError) as err:
            vpp.disconnect()
            raise RuntimeError('PAPI command {api}({args}) input error:\n{err}'.
                               format(api=api_name,
                                      args=api_args,
                                      err=repr(err)))
        except Exception as err:
            vpp.disconnect()
            raise RuntimeError('PAPI command {api}({args}) error:\n{exc}'.
                               format(api=api_name,
                                      args=api_args,
                                      exc=repr(err)))
    vpp.disconnect()

    return json.dumps(reply)


def process_stats(args):
    """Process the VPP Stats.

    :param args: Command line arguments passed to VPP PAPI Provider.
    :type args: ArgumentParser
    :returns: JSON formatted string.
    :rtype: str
    :raises RuntimeError: If PAPI command error occurs.
    """

    try:
        stats = VPPStats(args.socket)
    except Exception as err:
        raise RuntimeError('PAPI init failed:\n{err}'.format(err=repr(err)))

    json_data = json.loads(args.data)

    reply = list()

    for path in json_data:
        directory = stats.ls(path)
        data = stats.dump(directory)
        reply.append(data)

    return json.dumps(reply)


def main():
    """Main function for the Python API provider.
    """

    # The functions which process different types of VPP Python API methods.
    process_request = dict(
        request=process_json_request,
        dump=process_json_request,
        stats=process_stats
    )

    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        description=__doc__)
    parser.add_argument("-m", "--method",
                        required=True,
                        choices=[str(key) for key in process_request.keys()],
                        help="Specifies the VPP API methods: 1. request - "
                             "simple request / reply; 2. dump - dump function;"
                             "3. stats - VPP statistics.")
    parser.add_argument("-d", "--data",
                        required=True,
                        help="If the method is 'request' or 'dump', data is a "
                             "JSON string (list) containing API name(s) and "
                             "its/their input argument(s). "
                             "If the method is 'stats', data is a JSON string "
                             "containing the list of path(s) to the required "
                             "data.")
    parser.add_argument("-s", "--socket",
                        default="/var/run/vpp/stats.sock",
                        help="A file descriptor over the VPP stats Unix domain "
                             "socket. It is used only if method=='stats'.")

    args = parser.parse_args()

    return process_request[args.method](args)


if __name__ == '__main__':
    sys.stdout.write(main())
    sys.stdout.flush()
    sys.exit(0)