Webhook docs (#1248)

* Added documentation for polling/webhook modes

* Added changelog

* Added changelog

docs/dispatcher/webhook.rst

@@ -0,0 +1,125 @@
+.. _webhook:
+
+#######
+Webhook
+#######
+
+Telegram Bot API supports webhook.
+If you set webhook for your bot, Telegram will send updates to the specified url.
+You can use :meth:`aiogram.methods.set_webhook.SetWebhook` method to specify a url
+and receive incoming updates on it.
+
+.. note::
+
+    If you use webhook, you can't use long polling at the same time.
+
+Before start i'll recommend you to read `official Telegram's documentation about webhook <https://core.telegram.org/bots/webhooks>`_
+
+After you read it, you can start to read this section.
+
+Generally to use webhook with aiogram you should use any async web framework.
+Buy out of the box aiogram has an aiohttp integration, so we'll use it.
+
+.. note::
+
+    You can use any async web framework you want, but you should write your own integration if you don't use aiohttp.
+
+
+aiohttp integration
+===================
+
+Out of the box aiogram has aiohttp integration, so you can use it.
+
+Here is available few ways to do it using different implementations of the webhook controller:
+
+- :class:`aiogram.webhook.aiohttp_server.BaseRequestHandler` - Abstract class for aiohttp webhook controller
+- :class:`aiogram.webhook.aiohttp_server.SimpleRequestHandler`  - Simple webhook controller, uses single Bot instance
+- :class:`aiogram.webhook.aiohttp_server.TokenBasedRequestHandler`  - Token based webhook controller, uses multiple Bot instances and tokens
+
+You can use it as is or inherit from it and override some methods.
+
+.. autoclass:: aiogram.webhook.aiohttp_server.BaseRequestHandler
+    :members: __init__, register, close, resolve_bot, verify_secret, handle
+
+.. autoclass:: aiogram.webhook.aiohttp_server.SimpleRequestHandler
+    :members: __init__, register, close, resolve_bot, verify_secret, handle
+
+.. autoclass:: aiogram.webhook.aiohttp_server.TokenBasedRequestHandler
+    :members: __init__, register, close, resolve_bot, verify_secret, handle
+
+Security
+--------
+
+Telegram supports two methods to verify incoming requests that they are from Telegram:
+
+Using a secret token
+~~~~~~~~~~~~~~~~~~~~
+
+When you set webhook, you can specify a secret token and then use it to verify incoming requests.
+
+Using IP filtering
+~~~~~~~~~~~~~~~~~~
+
+You can specify a list of IP addresses from which you expect incoming requests, and then use it to verify incoming requests.
+
+It can be acy using firewall rules or nginx configuration or middleware on application level.
+
+So, aiogram has an implementation of the IP filtering middleware for aiohttp.
+
+.. autofunction:: aiogram.webhook.aiohttp_server.ip_filter_middleware
+
+.. autoclass:: aiogram.webhook.security.IPFilter
+    :members: __init__, allow, allow_ip, default, check
+
+Examples
+--------
+
+Behind reverse proxy
+~~~~~~~~~~~~~~~~~~~~
+
+In this example we'll use aiohttp as web framework and nginx as reverse proxy.
+
+.. literalinclude:: ../../examples/echo_bot_webhook.py
+
+When you use nginx as reverse proxy, you should set `proxy_pass` to your aiohttp server address.
+
+.. code-block:: nginx
+
+    location /webhook {
+        proxy_set_header Host $http_host;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_redirect off;
+        proxy_buffering off;
+        proxy_pass http://127.0.0.1:8080;
+    }
+
+
+Without reverse proxy (not recommended)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In case you want can't use reverse proxy, you can use aiohttp's ssl context.
+
+Also this example contains usage with self-signed certificate.
+
+.. literalinclude:: ../../examples/echo_bot_webhook_ssl.py
+
+
+With using other web framework
+==============================
+
+You can pass incoming request to aiogram's webhook controller from any web framework you want.
+
+Read more about it in :meth:`aiogram.dispatcher.dispatcher.Dispatcher.feed_webhook_update`
+or :meth:`aiogram.dispatcher.dispatcher.Dispatcher.feed_update` methods.
+
+.. code-block:: python
+
+    update = Update.model_validate(await request.json(), context={"bot": bot})
+    await dispatcher.feed_update(update)
+
+
+.. note::
+
+    If you want to use reply into webhook, you should check that result of the :code:`feed_update`
+    methods is an instance of API method and build :code:`multipart/form-data`
+    or :code:`application/json` response body manually.