From c3fa3315f5948a782bfcea3fbd7f2d4ceeb9c3ca Mon Sep 17 00:00:00 2001 From: Fabio Manganiello Date: Tue, 30 Aug 2022 23:35:19 +0200 Subject: [PATCH] Implemented synchronization with webhook responses. When a client triggers a `WebhookEvent` by calling a configured webhook over `/hook/`, the server will now wait for the configured `@hook` function to complete and it will return the returned response back to the client. This makes webhooks much more powerful, as they can be used to proxy HTTP calls or other services, and in general return something to the client instead of just executing actions. --- platypush/backend/http/app/routes/hook.py | 36 ++++++++++--- platypush/event/hook.py | 63 +++++++++++++---------- platypush/message/event/http/hook.py | 48 +++++++++++++++-- 3 files changed, 107 insertions(+), 40 deletions(-) diff --git a/platypush/backend/http/app/routes/hook.py b/platypush/backend/http/app/routes/hook.py index 5243039c..bcf33c50 100644 --- a/platypush/backend/http/app/routes/hook.py +++ b/platypush/backend/http/app/routes/hook.py @@ -1,9 +1,11 @@ import json -from flask import Blueprint, abort, request, Response +from flask import Blueprint, abort, request +from flask.wrappers import Response from platypush.backend.http.app import template_folder from platypush.backend.http.app.utils import logger, send_message +from platypush.config import Config from platypush.message.event.http.hook import WebhookEvent @@ -15,9 +17,11 @@ __routes__ = [ ] -@hook.route('/hook/', methods=['GET', 'POST', 'PUT', 'DELETE', 'PATCH', 'OPTIONS']) -def _hook(hook_name): - """ Endpoint for custom webhooks """ +@hook.route( + '/hook/', methods=['GET', 'POST', 'PUT', 'DELETE', 'PATCH', 'OPTIONS'] +) +def hook_route(hook_name): + """Endpoint for custom webhooks""" event_args = { 'hook': hook_name, @@ -28,20 +32,36 @@ def _hook(hook_name): } if event_args['data']: - # noinspection PyBroadException try: event_args['data'] = json.loads(event_args['data']) except Exception as e: - logger().warning('Not a valid JSON string: {}: {}'.format(event_args['data'], str(e))) + logger().warning( + 'Not a valid JSON string: %s: %s', event_args['data'], str(e) + ) event = WebhookEvent(**event_args) + matching_hooks = [ + hook + for hook in Config.get_event_hooks().values() + if hook.condition.type == WebhookEvent + and hook.condition.args.get('hook') == hook_name + and request.method.lower() + == hook.condition.args.get('method', request.method).lower() + ] try: send_message(event) - return Response(json.dumps({'status': 'ok', **event_args}), mimetype='application/json') + + # If there are matching hooks, wait for their completion before returning + if matching_hooks: + return event.wait_response(timeout=60) + + return Response( + json.dumps({'status': 'ok', **event_args}), mimetype='application/json' + ) except Exception as e: logger().exception(e) - logger().error('Error while dispatching webhook event {}: {}'.format(event, str(e))) + logger().error('Error while dispatching webhook event %s: %s', event, str(e)) abort(500, str(e)) diff --git a/platypush/event/hook.py b/platypush/event/hook.py index 7dc3140a..35cb052d 100644 --- a/platypush/event/hook.py +++ b/platypush/event/hook.py @@ -15,10 +15,10 @@ logger = logging.getLogger('platypush') def parse(msg): - """ Builds a dict given another dictionary or - a JSON UTF-8 encoded string/bytearray """ + """Builds a dict given another dictionary or + a JSON UTF-8 encoded string/bytearray""" - if isinstance(msg, bytes) or isinstance(msg, bytearray): + if isinstance(msg, (bytes, bytearray)): msg = msg.decode('utf-8') if isinstance(msg, str): try: @@ -30,8 +30,8 @@ def parse(msg): return msg -class EventCondition(object): - """ Event hook condition class """ +class EventCondition: + """Event hook condition class""" def __init__(self, type=Event.__class__, priority=None, **kwargs): """ @@ -55,8 +55,8 @@ class EventCondition(object): @classmethod def build(cls, rule): - """ Builds a rule given either another EventRule, a dictionary or - a JSON UTF-8 encoded string/bytearray """ + """Builds a rule given either another EventRule, a dictionary or + a JSON UTF-8 encoded string/bytearray""" if isinstance(rule, cls): return rule @@ -64,8 +64,7 @@ class EventCondition(object): rule = parse(rule) assert isinstance(rule, dict), f'Not a valid rule: {rule}' - type = get_event_class_by_type( - rule.pop('type') if 'type' in rule else 'Event') + type = get_event_class_by_type(rule.pop('type') if 'type' in rule else 'Event') args = {} for (key, value) in rule.items(): @@ -75,8 +74,8 @@ class EventCondition(object): class EventAction(Request): - """ Event hook action class. It is a special type of runnable request - whose fields can be configured later depending on the event context """ + """Event hook action class. It is a special type of runnable request + whose fields can be configured later depending on the event context""" def __init__(self, target=None, action=None, **args): if target is None: @@ -99,16 +98,16 @@ class EventAction(Request): return super().build(action) -class EventHook(object): - """ Event hook class. It consists of one conditions and - one or multiple actions to be executed """ +class EventHook: + """Event hook class. It consists of one conditions and + one or multiple actions to be executed""" def __init__(self, name, priority=None, condition=None, actions=None): - """ Constructor. Takes a name, a EventCondition object and an event action - procedure as input. It may also have a priority attached - as a positive number. If multiple hooks match against an event, - only the ones that have either the maximum match score or the - maximum pre-configured priority will be run. """ + """Constructor. Takes a name, a EventCondition object and an event action + procedure as input. It may also have a priority attached + as a positive number. If multiple hooks match against an event, + only the ones that have either the maximum match score or the + maximum pre-configured priority will be run.""" self.name = name self.condition = EventCondition.build(condition or {}) @@ -118,8 +117,8 @@ class EventHook(object): @classmethod def build(cls, name, hook): - """ Builds a rule given either another EventRule, a dictionary or - a JSON UTF-8 encoded string/bytearray """ + """Builds a rule given either another EventRule, a dictionary or + a JSON UTF-8 encoded string/bytearray""" if isinstance(hook, cls): return hook @@ -146,14 +145,14 @@ class EventHook(object): return cls(name=name, condition=condition, actions=actions, priority=priority) def matches_event(self, event): - """ Returns an EventMatchResult object containing the information - about the match between the event and this hook """ + """Returns an EventMatchResult object containing the information + about the match between the event and this hook""" return event.matches_condition(self.condition) def run(self, event): - """ Checks the condition of the hook against a particular event and - runs the hook actions if the condition is met """ + """Checks the condition of the hook against a particular event and + runs the hook actions if the condition is met""" def _thread_func(result): set_thread_name('Event-' + self.name) @@ -163,7 +162,9 @@ class EventHook(object): if result.is_match: logger.info('Running hook {} triggered by an event'.format(self.name)) - threading.Thread(target=_thread_func, name='Event-' + self.name, args=(result,)).start() + threading.Thread( + target=_thread_func, name='Event-' + self.name, args=(result,) + ).start() def hook(event_type=Event, **condition): @@ -172,8 +173,14 @@ def hook(event_type=Event, **condition): f.condition = EventCondition(type=event_type, **condition) @wraps(f) - def wrapped(*args, **kwargs): - return exec_wrapper(f, *args, **kwargs) + def wrapped(event, *args, **kwargs): + from platypush.message.event.http.hook import WebhookEvent + + response = exec_wrapper(f, event, *args, **kwargs) + if isinstance(event, WebhookEvent): + event.send_response(response) + + return response return wrapped diff --git a/platypush/message/event/http/hook.py b/platypush/message/event/http/hook.py index b423e844..1c1690d9 100644 --- a/platypush/message/event/http/hook.py +++ b/platypush/message/event/http/hook.py @@ -1,11 +1,26 @@ +import json +import uuid + from platypush.message.event import Event +from platypush.utils import get_redis + class WebhookEvent(Event): """ Event triggered when a custom webhook is called. """ - def __init__(self, *argv, hook, method, data=None, args=None, headers=None, **kwargs): + def __init__( + self, + *argv, + hook, + method, + data=None, + args=None, + headers=None, + response=None, + **kwargs, + ): """ :param hook: Name of the invoked web hook, from http://host:port/hook/ :type hook: str @@ -21,10 +36,35 @@ class WebhookEvent(Event): :param headers: Request headers :type args: dict - """ - super().__init__(hook=hook, method=method, data=data, args=args or {}, - headers=headers or {}, *argv, **kwargs) + :param response: Response returned by the hook. + :type args: dict | list | str + """ + # This queue is used to synchronize with the hook and wait for its completion + kwargs['response_queue'] = kwargs.get( + 'response_queue', f'platypush/webhook/{str(uuid.uuid1())}' + ) + + super().__init__( + *argv, + hook=hook, + method=method, + data=data, + args=args or {}, + headers=headers or {}, + response=response, + **kwargs, + ) + + def send_response(self, response): + output = response.output + if isinstance(output, (dict, list)): + output = json.dumps(output) + + get_redis().rpush(self.args['response_queue'], output) + + def wait_response(self, timeout=None): + return get_redis().blpop(self.args['response_queue'], timeout=timeout)[1] # vim:sw=4:ts=4:et: