"""
REST session for Webex API requests
"""
import asyncio
import json as json_mod
import logging
import urllib.parse
import uuid
from asyncio import Semaphore
from collections.abc import AsyncGenerator
from functools import wraps
from io import TextIOBase, StringIO
from time import perf_counter_ns
from typing import Tuple, Type, Optional
from aiohttp import ClientSession, ClientResponse, ClientResponseError, RequestInfo
from aiohttp.typedefs import LooseHeaders
from pydantic import BaseModel, Field
from .base import ApiModel
from .base import StrOrDict
from .tokens import Tokens
__all__ = ['AsSingleError', 'AsErrorDetail', 'AsRestError', 'as_dump_response', 'AsRestSession']
log = logging.getLogger(__name__)
[docs]class AsSingleError(BaseModel):
"""
Representation of single error in the body of an HTTP error response from Webex
"""
description: str
error_code: Optional[int] = Field(alias='errorCode')
@property
def code(self) -> Optional[int]:
"""
Error code or None
:return: error code
"""
return self.error_code
[docs]class AsErrorDetail(ApiModel):
"""
Representation of error details in the body of an HTTP error response from Webex
"""
error_code: Optional[int] = Field(alias='errorCode')
message: str #: error message
errors: list[AsSingleError] #: list of errors; typically has a single entry
tracking_id: str #: tracking ID of the request
@property
def description(self) -> str:
"""
error description
"""
return self.errors and self.errors[0].description or ''
@property
def code(self) -> Optional[int]:
"""
error code
"""
return self.errors and self.errors[0].code or None
[docs]class AsRestError(ClientResponseError):
"""
A REST error
"""
def __init__(self, request_info: RequestInfo, history: Tuple[ClientResponse, ...], *, code: Optional[int] = None,
status: Optional[int] = None, message: str = "", headers: Optional[LooseHeaders] = None) -> None:
super().__init__(request_info, history, code=code, status=status, message=message, headers=headers)
# TODO: implement equivalent to __init__ in sync implementation
[docs]def as_dump_response(*, response: ClientResponse, response_data=None, data=None,
json=None, file: TextIOBase = None, dump_log: logging.Logger = None,
diff_ns: int = None):
"""
Dump response object to log file
:param response: HTTP request response
:param response_data:
:param data:
:param json:
:param file: stream to dump to
:type file: TextIOBase
:param dump_log: logger to dump to
:type dump_log: logging.Logger
:param diff_ns: time the request took (in ns)
:type diff_ns: int
"""
if not log.isEnabledFor(logging.DEBUG):
return
dump_log = dump_log or log
output = file or StringIO()
# dump response objects in redirect history
for h in response.history:
as_dump_response(response=h, file=output)
if diff_ns is None:
time_str = ''
else:
time_str = f'({diff_ns / 1000000.0:.3f} ms)'
print(f'Request {response.status}[{response.reason}]{time_str}: '
f'{response.request_info.method} {response.request_info.url}', file=output)
# request headers
for k, v in response.request_info.headers.items():
if k.lower() == 'authorization':
v = 'Bearer ***'
print(f' {k}: {v}', file=output)
# request body
body_str = ''
if isinstance(data, dict):
body_str = str(urllib.parse.quote_plus(urllib.parse.urlencode(data)))
elif isinstance(data, str):
body_str = data
elif json:
body_str = json_mod.dumps(json)
if body_str:
print(' --- body ---', file=output)
print(f' {body_str}', file=output)
print(' Response', file=output)
# response headers
for k in response.headers:
print(f' {k}: {response.headers[k]}', file=output)
# dump response body
if response_data:
print(' --- response body ---', file=output)
try:
body = response_data
if 'access_token' in body:
# mask access token
body['access_token'] = '***'
elif 'refresh_token' in body:
body['refresh_token'] = '***'
body = json_mod.dumps(body, indent=2)
except json_mod.JSONDecodeError:
pass
for line in body.splitlines():
print(f' {line}', file=output)
print(' --- end ---', file=output)
if file is None:
dump_log.debug(output.getvalue())
def retry_request(func):
"""
Decorator for the request method in the AsRestSession class. Used to implement backoff on 429 responses
:param func:
:return:
"""
async def giveup_429(e: ClientResponseError) -> bool:
"""
callback for backoff on REST requests
:param e: latest exception
:return: True -> break the backoff loop
"""
if e.status != 429:
# Don't retry on anything other than 429
return True
# determine how long we have to wait
retry_after = int(e.headers.get('Retry-After', 5))
# never wait more than the defined maximum of 20 s
retry_after = min(retry_after, 20)
log.warning(f'429 retry after {retry_after} on {e.request_info.method} {e.request_info.url}')
await asyncio.sleep(retry_after)
return False
@wraps(func)
async def wrapper(session: 'AsRestSession', *args, **kwargs):
async with session._sem:
while True:
try:
result = await func(session, *args, **kwargs)
except ClientResponseError as e:
if await giveup_429(e):
raise
else:
break
return result
return wrapper
[docs]class AsRestSession(ClientSession):
"""
REST session used for API requests:
* includes an Authorization header in reach request
* implements retries on 429
* loads deserializes JSON data if needed
"""
#: base URL for all Webex API requests
BASE = 'https://webexapis.com/v1'
def __init__(self, *, tokens: Tokens, concurrent_requests: int):
super().__init__()
self._tokens = tokens
self._sem = Semaphore(concurrent_requests)
def ep(self, path: str = None):
"""
get an API endpoint
:param path:
:return: full endpoint
:meta private:
"""
path = path and f'/{path}' or ''
return f'{self.BASE}{path}'
@property
def access_token(self) -> str:
"""
access token used for all requests
:return: access token
:rtype: str
"""
return self._tokens.access_token
@retry_request
async def _request_w_response(self, method: str, url: str, headers=None, content_type: str = None,
data=None, json=None, **kwargs) -> Tuple[ClientResponse, StrOrDict]:
"""
low level API REST request with support for 429 rate limiting
:param method: HTTP method
:type method: str
:param url: URL
:type url: str
:param headers: prepared headers for request
:type headers: Optional[dict]
:param content_type:
:type content_type: str
:param kwargs: additional keyward args
:type kwargs: dict
:return: Tuple of response object and body. Body can be text or dict (parsed from JSON body)
:rtype:
"""
request_headers = {'authorization': f'Bearer {self._tokens.access_token}',
'content-type': 'application/json;charset=utf-8',
'TrackingID': f'SIMPLE_{uuid.uuid4()}'}
if headers:
request_headers.update((k.lower(), v) for k, v in headers.items())
if content_type:
request_headers['content-type'] = content_type
# the event is cleared if any task hit a 429
start = perf_counter_ns()
async with self.request(method, url=url, headers=request_headers,
data=data, json=json, **kwargs) as response:
# get response body as text or dict (parsed JSON)
ct = response.headers.get('Content-Type')
if not ct:
response_data = ''
elif ct.startswith('application/json'):
response_data = await response.json()
else:
response_data = await response.text()
diff_ns = perf_counter_ns() - start
as_dump_response(response=response, data=data, json=json, response_data=response_data, diff_ns=diff_ns)
try:
response.raise_for_status()
except ClientResponseError as error:
# create a RestError based on HTTP error
error = AsRestError(request_info=error.request_info,
history=error.history, status=error.status,
message=error.message, headers=error.headers)
raise error
return response, response_data
async def _rest_request(self, method: str, url: str, **kwargs) -> StrOrDict:
"""
low level API request only returning the body
:param method: HTTP method
:type method: str
:param url: URL
:type url: str
:param headers: prepared headers for request
:type headers: Optional[dict]
:param kwargs: additional keyward args
:type kwargs: dict
:return: body. Body can be text or dict (parsed from JSON body)
:rtype: Unon
"""
_, data = await self._request_w_response(method, url=url, **kwargs)
return data
[docs] async def rest_get(self, *args, **kwargs) -> StrOrDict:
"""
GET request
:param args:
:param kwargs:
:return: deserialized JSON content or body text
"""
return await self._rest_request('GET', *args, **kwargs)
[docs] async def rest_post(self, *args, **kwargs) -> StrOrDict:
"""
POST request
:param args:
:param kwargs:
:return: deserialized JSON content or body text
"""
return await self._rest_request('POST', *args, **kwargs)
[docs] async def rest_put(self, *args, **kwargs) -> StrOrDict:
"""
PUT request
:param args:
:param kwargs:
:return: deserialized JSON content or body text
"""
return await self._rest_request('PUT', *args, **kwargs)
[docs] async def rest_delete(self, *args, **kwargs) -> None:
"""
DELETE request
:param args:
:param kwargs:
"""
await self._rest_request('DELETE', *args, **kwargs)
[docs] async def rest_patch(self, *args, **kwargs) -> StrOrDict:
"""
PATCH request
:param args:
:param kwargs:
"""
return await self._rest_request('PATCH', *args, **kwargs)