"""Webhook HTTP requests."""
from __future__ import absolute_import, unicode_literals
import thorn
import requests
import socket
from contextlib import contextmanager
from celery import uuid
from celery.utils import cached_property
from requests.exceptions import ConnectionError, Timeout
from requests.packages.urllib3.util.url import Url, parse_url
from vine import maybe_promise, promise
from vine.abstract import Thenable, ThenableProxy
from ._state import app_or_default
from .utils.compat import bytes_if_py2, restore_from_keys
from .utils.log import get_logger
from .validators import (
block_internal_ips, deserialize_validator, serialize_validator,
)
__all__ = ['Request']
F_USER_AGENT = 'Mozilla/5.0 (compatible; thorn/{version}; {requests_UA})'
DEFAULT_USER_AGENT = F_USER_AGENT.format(
version=thorn.__version__,
requests_UA=requests.utils.default_user_agent(),
)
REQUEST_REPR = '<{0}: {1.event} -> {1.subscriber.url} sender={1.sender!r}>'
logger = get_logger(__name__)
[docs]@Thenable.register
class Request(ThenableProxy):
"""Webhook HTTP request.
Arguments:
event (str): Name of event.
data (Any): Event payload.
sender (Any): Sender of event (or :const:`None`).
subscriber (~thorn.generic.models.Subscriber): Subscriber to
dispatch the request for.
Keyword Arguments:
on_success (Callable): Optional callback called if
the HTTP request succeeds. Must take single argument: ``request``.
on_timeout (Callable): Optional callback called if the HTTP request
times out. Must have signature: ``(request, exc)``.
on_error (Callable): Optional callback called if the HTTP request
fails. Must have signature: ``(request, exc)``.
headers (Mapping): Additional HTTP headers to send with the request.
user_agent (str): Set custom HTTP user agent.
recipient_validators (Sequence): List of serialized recipient
validators.
allow_keepalive (bool): Allow reusing session for this HTTP request.
Enabled by default.
retry (bool): Retry in the event of timeout/failure?
Disabled by default.
retry_max (int): Maximum number of times to retry before giving up.
Default is 3.
retry_delay (float): Delay between retries in seconds int/float.
Default is 60 seconds.
"""
app = None
Session = requests.Session
#: Holds the response after the HTTP request is performed.
response = None
#: Tuple of exceptions considered a connection error.
connection_errors = (ConnectionError,)
#: Tuple of exceptions considered a timeout error.
timeout_errors = (Timeout,)
#: HTTP User-Agent header.
user_agent = DEFAULT_USER_AGENT
def __init__(self, event, data, sender, subscriber,
id=None, on_success=None, on_error=None,
timeout=None, on_timeout=None,
retry=None, retry_max=None, retry_delay=None,
headers=None, user_agent=None, app=None,
recipient_validators=None,
allow_keepalive=True,
allow_redirects=None):
# type: (str, Dict, Any, Subscriber, str, Callable,
# Callable, float, Callable, bool, int,
# float, Mapping, str, App, Sequence[Callable],
# bool, bool) -> None
self.app = app_or_default(app or self.app)
self.id = id or uuid()
self.event = event
self.data = data
self.sender = sender
self.subscriber = subscriber
self.timeout = timeout
self.on_success = on_success
self.on_timeout = maybe_promise(on_timeout)
self.on_error = on_error
self.retry = self.app.settings.THORN_RETRY if retry is None else retry
self.retry_max = (
self.app.settings.THORN_RETRY_MAX
if retry_max is None else retry_max)
self.retry_delay = (
self.app.settings.THORN_RETRY_DELAY
if retry_delay is None else retry_delay)
if recipient_validators is None:
recipient_validators = self.app.settings.THORN_RECIPIENT_VALIDATORS
self.allow_keepalive = allow_keepalive
if allow_redirects is None:
allow_redirects = self.app.settings.THORN_ALLOW_REDIRECTS
self.allow_redirects = allow_redirects
self._recipient_validators = recipient_validators
self.response = None
self._headers = headers
self._set_promise_target(promise(
args=(self,), callback=self.on_success, on_error=self.on_error,
))
if user_agent:
self.user_agent = user_agent
[docs] def validate_recipient(self, url):
# type: (str) -> None
[validate(url) for validate in self.recipient_validators]
[docs] def sign_request(self, subscriber, data):
# type: (Subscriber, str) -> str
return subscriber.sign(data)
[docs] def dispatch(self, session=None, propagate=False):
# type: (requests.Session, bool) -> 'Request'
if not self.cancelled:
self.validate_recipient(self.subscriber.url)
with self._finalize_unless_request_error(propagate):
self.response = self.post(session=session)
return self
@contextmanager
def _finalize_unless_request_error(self, propagate=False):
# type: (bool) -> Any
try:
yield
except self.timeout_errors as exc:
self.handle_timeout_error(exc, propagate=propagate)
except self.connection_errors as exc:
self.handle_connection_error(exc, propagate=propagate)
else:
self._p()
[docs] @contextmanager
def session_or_acquire(self, session=None, close_session=False):
# type: (requests.Session, bool) -> Any
if session is None or not self.allow_keepalive:
session, close_session = self.Session(), True
try:
yield session
finally:
if close_session and session is not None:
session.close()
[docs] def to_safeurl(self, url):
# type: (str) -> Tuple[str, str]
# Try and see if there is any sort of redirection in the recipient URL
# if yes, get the final URL to be passed into the validator
if self.allow_redirects:
try:
_dummy_resp = requests.head(url, allow_redirects=True)
url = _dummy_resp.url
except ConnectionError:
logger.warning("Recipient URL not reachable")
parts = parse_url(url)
host = parts.host
addr = socket.gethostbyname(host)
safeurl = Url(
scheme=parts.scheme,
auth=parts.auth,
host=addr,
port=parts.port,
path=parts.path,
query=parts.query,
fragment=parts.fragment,
)
block_internal_ips()(addr)
return host, safeurl.url
[docs] def post(self, session=None):
# type: (requests.Session) -> requests.Response
host, url = self.to_safeurl(self.subscriber.url)
with self.session_or_acquire(session) as session:
return session.post(
url=url,
data=self.data,
allow_redirects=self.allow_redirects,
timeout=self.timeout,
headers=self.annotate_headers({
'Hook-HMAC': self.sign_request(self.subscriber, self.data),
'Hook-Subscription': str(self.subscriber.uuid),
'Host': host,
}),
verify=False,
)
[docs] def handle_timeout_error(self, exc, propagate=False):
# type: (Exception, bool) -> Any
logger.info('Timed out while dispatching webhook request: %r',
exc, exc_info=1, extra={'data': self.as_dict()})
if self.on_timeout:
return self.on_timeout(self, exc)
return self._p.throw(exc, propagate=propagate)
[docs] def handle_connection_error(self, exc, propagate=False):
# type: (Exception, bool) -> None
logger.error('Error dispatching webhook request: %r',
exc, exc_info=1, extra={'data': self.as_dict()})
self._p.throw(exc, propagate=propagate)
[docs] def as_dict(self):
# type: () -> Dict[str, Any]
"""Return dictionary representation of this request.
Note:
All values must be json serializable.
"""
return {
'id': self.id,
'event': self.event,
'sender': self.sender,
'subscriber': self.subscriber.as_dict(),
'data': self.data,
'timeout': self.timeout,
'retry': self.retry,
'retry_max': self.retry_max,
'retry_delay': self.retry_delay,
'recipient_validators': self._serialize_validators(
self._recipient_validators,
),
'allow_keepalive': self.allow_keepalive,
}
def _serialize_validators(self, validators):
# not serialized will be callable, some may have already
# been deserialized.
# type: (Sequence) -> Sequence
return [serialize_validator(v)
for v in validators if callable(v)]
def __repr__(self):
# type: () -> str
return bytes_if_py2(REQUEST_REPR.format(type(self).__name__, self))
def __reduce__(self):
return restore_from_keys, (type(self), (), self.__reduce_keys__())
def __reduce_keys__(self):
# type: () -> Dict[str, Any]
return dict(
self.as_dict(),
headers=self._headers,
user_agent=self.user_agent,
)
@property
def default_headers(self):
# type: () -> Dict[str, Any]
return {
'Content-Type': self.subscriber.content_type,
'User-Agent': self.user_agent,
'Hook-Event': self.event,
'Hook-Delivery': self.id,
}
[docs] @cached_property
def urlident(self):
# type: () -> Tuple[str, int, str]
"""Used to order HTTP requests by URL."""
url = parse_url(self.subscriber.url)
return url.scheme or 'http', url.port or 80, url.host
@property
def value(self):
# type: () -> Optional[requests.Response]
return self.response # here for Thenable-compatiblity.
[docs] @cached_property
def recipient_validators(self):
# type: () -> Sequence[Callable]
return [
deserialize_validator(v) for v in self._recipient_validators
]
