Merge pull request #4640 from mhils/upgrade-docs

Add Addon Upgrade Docs for mitmproxy 7

docs/src/content/addons-api-changelog.md

@@ -0,0 +1,64 @@
+---
+title: "API Changelog"
+layout: single
+menu:
+    addons:
+        weight: 9
+---
+
+# API Changelog
+
+We try to avoid them, but this page lists breaking changes in the mitmproxy addon API.
+
+## mitmproxy 7.0
+
+#### Connection Events
+
+We've revised mitmproxy's connection-specific event hooks as part of the new proxy core. The `.client_conn` and 
+`.server_conn` objects have major API changes across the board. See the new 
+[event hook documentation]({{< relref "addons-api#ConnectionEvents" >}}) for details. 
+
+| Attribute      | Client (v6) | Server (v6)       | mitmproxy v7 |
+|----------------|-------------|-------------------|--------------|
+| Remote IP:Port | `.address`  | `.ip_address`     | `.peername`  |
+| Local IP:Port  | ❌          | `.source_address` | `.sockname`  |
+| Remote Domain  | N/A         | `.address`        | `.address`   |
+
+
+As the passed objects are different now, we've also taken this opportunity to introduce more consistent event names:
+
+| mitmproxy 6        | mitmproxy 7           |
+| ------------------ | --------------------- |
+| `clientconnect`    | `client_connected`    |
+| `clientdisconnect` | `client_disconnected` |
+| ❌                 | `server_connect`      |
+| `serverconnect`    | `server_connected`    |
+| `serverdisconnect` | `server_disconnected` |
+
+#### Logging
+
+The `log` event has been renamed to `add_log`. This fixes a consistent source of errors where users imported 
+modules with the name "log", which were then inadvertedly picked up.
+
+#### Contentviews
+
+Contentviews now implement `render_priority` instead of `should_render`. This enables additional specialization, for
+example one can now write contentviews that pretty-print only specific JSON responses.
+See the [contentview.py]({{< relref "addons-examples#contentview" >}}) example for details.
+
+#### WebSocket Flows
+
+mitmproxy 6 had a custom WebSocketFlow class, which had 
+[ugly co-dependencies with the related HTTPFlow](https://github.com/mitmproxy/mitmproxy/issues/4425). Long story short,
+WebSocketFlow is no more and instead HTTPFlow has a neat 
+[`.websocket` attribute]({{< relref "api/mitmproxy.http.md#HTTPFlow.websocket" >}}). All WebSocket flows are now passed
+the originating `HTTPFlow` with this attribute set. As always, existing dumpfiles are automatically converted on load.
+
+#### Certificates
+
+mitmproxy now uses `cryptography` instead of `pyOpenSSL` to generate certificates. As a consequence, the API of
+`mitmproxy.certs` has changed.
+
+#### HTTP Headers
+
+`mitmproxy.net.http.Headers` -> `mitmproxy.http.Headers` for consistency.