web_server/utils/api_utils.py

#
#  Copyright 2019 The FATE Authors. All Rights Reserved.
#
#  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.
#
import json
import random
import time
from functools import wraps
from io import BytesIO
from flask import (
    Response, jsonify, send_file,make_response,
    request as flask_request,
)
from werkzeug.http import HTTP_STATUS_CODES

from web_server.utils import json_dumps
from web_server.versions import get_fate_version
from web_server.settings import RetCode
from web_server.settings import (
    REQUEST_MAX_WAIT_SEC, REQUEST_WAIT_SEC,
    stat_logger,CLIENT_AUTHENTICATION, HTTP_APP_KEY, SECRET_KEY
)
import requests
import functools
from web_server.utils import CustomJSONEncoder
from uuid import uuid1
from base64 import b64encode
from hmac import HMAC
from urllib.parse import quote, urlencode


requests.models.complexjson.dumps = functools.partial(json.dumps, cls=CustomJSONEncoder)


def request(**kwargs):
    sess = requests.Session()
    stream = kwargs.pop('stream', sess.stream)
    timeout = kwargs.pop('timeout', None)
    kwargs['headers'] = {k.replace('_', '-').upper(): v for k, v in kwargs.get('headers', {}).items()}
    prepped = requests.Request(**kwargs).prepare()

    if CLIENT_AUTHENTICATION and HTTP_APP_KEY and SECRET_KEY:
        timestamp = str(round(time() * 1000))
        nonce = str(uuid1())
        signature = b64encode(HMAC(SECRET_KEY.encode('ascii'), b'\n'.join([
            timestamp.encode('ascii'),
            nonce.encode('ascii'),
            HTTP_APP_KEY.encode('ascii'),
            prepped.path_url.encode('ascii'),
            prepped.body if kwargs.get('json') else b'',
            urlencode(sorted(kwargs['data'].items()), quote_via=quote, safe='-._~').encode('ascii')
            if kwargs.get('data') and isinstance(kwargs['data'], dict) else b'',
        ]), 'sha1').digest()).decode('ascii')

        prepped.headers.update({
            'TIMESTAMP': timestamp,
            'NONCE': nonce,
            'APP-KEY': HTTP_APP_KEY,
            'SIGNATURE': signature,
        })

    return sess.send(prepped, stream=stream, timeout=timeout)


fate_version = get_fate_version() or ''


def get_exponential_backoff_interval(retries, full_jitter=False):
    """Calculate the exponential backoff wait time."""
    # Will be zero if factor equals 0
    countdown = min(REQUEST_MAX_WAIT_SEC, REQUEST_WAIT_SEC * (2 ** retries))
    # Full jitter according to
    # https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/
    if full_jitter:
        countdown = random.randrange(countdown + 1)
    # Adjust according to maximum wait time and account for negative values.
    return max(0, countdown)


def get_json_result(retcode=RetCode.SUCCESS, retmsg='success', data=None, job_id=None, meta=None):
    import re
    result_dict = {
        "retcode": retcode,
        "retmsg":retmsg,
        # "retmsg": re.sub(r"fate", "seceum", retmsg, flags=re.IGNORECASE),
        "data": data,
        "jobId": job_id,
        "meta": meta,
    }

    response = {}
    for key, value in result_dict.items():
        if value is None and key != "retcode":
            continue
        else:
            response[key] = value
    return jsonify(response)

def get_data_error_result(retcode=RetCode.DATA_ERROR, retmsg='Sorry! Data missing!'):
    import re
    result_dict = {"retcode": retcode, "retmsg": re.sub(r"fate", "seceum", retmsg, flags=re.IGNORECASE)}
    response = {}
    for key, value in result_dict.items():
        if value is None and key != "retcode":
            continue
        else:
            response[key] = value
    return jsonify(response)

def server_error_response(e):
    stat_logger.exception(e)
    try:
        if e.code==401:
            return get_json_result(retcode=401, retmsg=repr(e))
    except:
        pass
    if len(e.args) > 1:
        return get_json_result(retcode=RetCode.EXCEPTION_ERROR, retmsg=repr(e.args[0]), data=e.args[1])
    return get_json_result(retcode=RetCode.EXCEPTION_ERROR, retmsg=repr(e))


def error_response(response_code, retmsg=None):
    if retmsg is None:
        retmsg = HTTP_STATUS_CODES.get(response_code, 'Unknown Error')

    return Response(json.dumps({
        'retmsg': retmsg,
        'retcode': response_code,
    }), status=response_code, mimetype='application/json')


def validate_request(*args, **kwargs):
    def wrapper(func):
        @wraps(func)
        def decorated_function(*_args, **_kwargs):
            input_arguments = flask_request.json or flask_request.form.to_dict()
            no_arguments = []
            error_arguments = []
            for arg in args:
                if arg not in input_arguments:
                    no_arguments.append(arg)
            for k, v in kwargs.items():
                config_value = input_arguments.get(k, None)
                if config_value is None:
                    no_arguments.append(k)
                elif isinstance(v, (tuple, list)):
                    if config_value not in v:
                        error_arguments.append((k, set(v)))
                elif config_value != v:
                    error_arguments.append((k, v))
            if no_arguments or error_arguments:
                error_string = ""
                if no_arguments:
                    error_string += "required argument are missing: {}; ".format(",".join(no_arguments))
                if error_arguments:
                    error_string += "required argument values: {}".format(",".join(["{}={}".format(a[0], a[1]) for a in error_arguments]))
                return get_json_result(retcode=RetCode.ARGUMENT_ERROR, retmsg=error_string)
            return func(*_args, **_kwargs)
        return decorated_function
    return wrapper


def is_localhost(ip):
    return ip in {'127.0.0.1', '::1', '[::1]', 'localhost'}


def send_file_in_mem(data, filename):
    if not isinstance(data, (str, bytes)):
        data = json_dumps(data)
    if isinstance(data, str):
        data = data.encode('utf-8')

    f = BytesIO()
    f.write(data)
    f.seek(0)

    return send_file(f, as_attachment=True, attachment_filename=filename)


def get_json_result(retcode=RetCode.SUCCESS, retmsg='success', data=None):
    response = {"retcode": retcode, "retmsg": retmsg, "data": data}
    return jsonify(response)


def cors_reponse(retcode=RetCode.SUCCESS, retmsg='success', data=None, auth=None):
    result_dict = {"retcode": retcode, "retmsg": retmsg, "data": data}
    response_dict = {}
    for key, value in result_dict.items():
        if value is None and key != "retcode":
            continue
        else:
            response_dict[key] = value
    response = make_response(jsonify(response_dict))
    if auth:
        response.headers["Authorization"] = auth
    response.headers["Access-Control-Allow-Origin"] = "*"
    response.headers["Access-Control-Allow-Method"] = "*"
    response.headers["Access-Control-Allow-Headers"] = "*"
    response.headers["Access-Control-Allow-Headers"] = "*"
    response.headers["Access-Control-Expose-Headers"] = "Authorization"
    return response