Serve preview files from non-default recording roots via nginx

When cameras are configured with recording paths outside /media/frigate
(e.g. /video1, /video2), preview mp4 files generated there had no
corresponding nginx location block — requests returned 404.

At nginx startup, get_nginx_settings.py now extracts unique recording
roots outside /media/frigate from the Frigate config. The nginx run
script uses a new extra_recordings.gotmpl template to generate
location blocks (e.g. /video1/preview/) with alias directives for
each such root, included via extra_recordings.conf.

The API already returns correct src URLs for these paths (the existing
replace(BASE_DIR, "") leaves non-media paths unchanged), so no API
changes are needed.

https://claude.ai/code/session_016bxjbVpx8DqpjysnGYmXdx

docker/main/rootfs/etc/s6-overlay/s6-rc.d/nginx/run

@@ -89,6 +89,11 @@ python3 /usr/local/nginx/get_nginx_settings.py | \
     tempio -template /usr/local/nginx/templates/listen.gotmpl \
            -out /usr/local/nginx/conf/listen.conf
 
+# build location blocks for recording roots outside /media/frigate
+python3 /usr/local/nginx/get_nginx_settings.py | \
+    tempio -template /usr/local/nginx/templates/extra_recordings.gotmpl \
+           -out /usr/local/nginx/conf/extra_recordings.conf
+
 # Replace the bash process with the NGINX process, redirecting stderr to stdout
 exec 2>&1
 exec \

docker/main/rootfs/usr/local/nginx/conf/nginx.conf

@@ -101,6 +101,7 @@ http {
 
         include auth_location.conf;
         include base_path.conf;
+        include extra_recordings.conf;
 
         location /vod/ {
             include auth_request.conf;

docker/main/rootfs/usr/local/nginx/get_nginx_settings.py

@@ -52,11 +52,22 @@ listen_config["external_port"] = external_port
 
 base_path = os.environ.get("FRIGATE_BASE_PATH", "")
 
+# Collect recording roots that are outside the default /media/frigate tree.
+# Nginx needs an explicit location block for each such root to serve preview files.
+_default_recordings = "/media/frigate"
+_extra_roots: set[str] = set()
+for _cam_cfg in config.get("cameras", {}).values():
+    if isinstance(_cam_cfg, dict):
+        _path = _cam_cfg.get("path", "")
+        if _path and not _path.startswith(_default_recordings):
+            _extra_roots.add(_path.rstrip("/"))
+
 result: dict[str, Any] = {
     "tls": tls_config,
     "ipv6": ipv6_config,
     "listen": listen_config,
     "base_path": base_path,
+    "extra_recording_roots": sorted(_extra_roots),
 }
 
 print(json.dumps(result))

docker/main/rootfs/usr/local/nginx/templates/extra_recordings.gotmpl

@@ -0,0 +1,12 @@
+{{ range .extra_recording_roots }}
+location {{ . }}/preview/ {
+    include auth_request.conf;
+    types {
+        video/mp4 mp4;
+    }
+
+    expires 7d;
+    add_header Cache-Control "public";
+    alias {{ . }}/preview/;
+}
+{{ end }}