From 7b09b75836b4379da4084fa9aeee68fe183f4fcd Mon Sep 17 00:00:00 2001
From: nexy7574 <git@nexy7574.co.uk>
Date: Fri, 16 Feb 2024 21:10:03 +0000
Subject: [PATCH] Update the runtime

---
 README.md | 16 ++++++++++++----
 server.py | 22 +++++++++++++++++-----
 2 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index 9abd54e..ed87233 100644
--- a/README.md
+++ b/README.md
@@ -18,16 +18,24 @@ services:
   url_previews:
     environment:
       - "PREVIEW_HOMESERVER=https://matrix.nexy7574.co.uk"
+      - "FORWARDED_ALLOW_IPS=*"
     ports:
       - "2226:2226"
     restart: "unless-stopped"
     container_name: "dendrite-url-previews"
     volumes:
-      - ./data/:/app/data/
+      - url_previews:/app/data/
     build: .  # there's no pre-built image
+
+volumes:
+  url_previews:
 ```
 
 ## Configuration
-The only configuration option is `PREVIEW_HOMESERVER`, which is the homeserver to use for the previews.
-If not specified, it defaults to the host name of the request URL, which may not work in some reverse-proxy
-environments.
+
+| Environment Variable  | Description                                                                                        | Example                         | Default                           |
+|-----------------------|----------------------------------------------------------------------------------------------------|---------------------------------|-----------------------------------|
+| `PREVIEW_HOMESERVER`  | The homeserver to use for the previews.                                                            | `https://matrix.nexy7574.co.uk` | The host name of the request URL. |
+| `PREVIEW_HOST`        | The host IP/Name to listen to.                                                                     | `192.168.0.2`                   | `0.0.0.0`                         |
+| `PREVIEW_PORT`        | The port to listen to.                                                                             | `8080`                          | `2226`                            |
+| `FORWARDED_ALLOW_IPS` | The list of reverse proxy IPs to trust. See [Uvicorn docs](https://www.uvicorn.org/settings/#http) | `*`                             | `127.0.0.1`                       |
diff --git a/server.py b/server.py
index 95c79c6..f7f5e7d 100644
--- a/server.py
+++ b/server.py
@@ -19,7 +19,6 @@ from rich.logging import RichHandler
 from fastapi.middleware.cors import CORSMiddleware
 
 
-
 @contextlib.asynccontextmanager
 async def startup(_):
     if not CACHE_DIR.exists():
@@ -158,6 +157,7 @@ def upload_media(domain: str, access_token: str, file: io.BytesIO, filename: str
     )
     file.seek(0)
 
+    # noinspection PyTypeChecker
     response = httpx.post(
         "%s/_matrix/media/r0/upload" % domain,
         headers={
@@ -249,6 +249,7 @@ def preview_url(
         if tag_name in og_tags:
             _url = og_tags[tag_name]
             try:
+                # noinspection PyArgumentList
                 with httpx.stream(
                     url=_url,
                     method="GET",
@@ -285,8 +286,6 @@ def preview_url(
                                         int(response_media.headers["content-length"])
                                     )
                                 )
-                                # og_tags.pop(tag_name, None)
-                                # continue
                             _file.seek(0)
                         upload_response = upload_media(
                             domain,
@@ -318,9 +317,22 @@ def preview_url(
             "INSERT INTO cache (uuid, url, ts, metadata) VALUES (?, ?, ?, ?)",
             (str(uuid.uuid4()), url, round(time.time()), json.dumps(og_tags))
         )
-    return og_tags
+    return JSONResponse(
+        og_tags,
+        200,
+        headers={
+            "Cache-Control": "public, max-age=86400"
+        }
+    )
 
 
 if __name__ == "__main__":
     import uvicorn
-    uvicorn.run(app, host="0.0.0.0", port=2226)
+
+    uvicorn.run(
+        app,
+        host=os.getenv("PREVIEW_HOST", "0.0.0.0"),
+        port=int(os.getenv("PREVIEW_PORT", 2226)),
+        # If you want to enable reverse-proxy support, you must set the $FORWARDED_ALLOW_IPS environment variable.
+        # See: https://www.uvicorn.org/settings/#http
+    )