Harden container startup (#24718)

* keep /config out of the root environment in the frigate run script

The script exported HOME=/config and prepended /config/.local/lib to LD_LIBRARY_PATH while still root, then ran python3, ffmpeg, grep, and opt_in_out as root. The runtime user owns /config, so it could plant a .pth file in the user site-packages or a library on the loader path and get code run as root on the next start. Root helpers now run with root's environment (and python3 -I), and HOME, LD_LIBRARY_PATH, and PATH reach only the dropped process through env on the s6-setuidgid line. opt_in_out runs as the runtime user, so the openvino marker no longer gets written into /config by root.

* don't follow a planted symlink when writing /dev/shm/go2rtc.yaml

After the first start the go2rtc user owned /dev/shm/go2rtc.yaml and could swap it for a dangling symlink. The run script's -f test was false for a dangling link, so the link survived, and root's create_config.py then created the link target and the chown handed it to go2rtc. The run script now removes any existing entry, create_config.py creates the file with O_EXCL and O_NOFOLLOW at mode 0640, and the chown uses -h.

* run root python helpers in isolated mode and keep HOME=/config for non-root containers

The previous commit only set HOME=/config when dropping from root, so a container started with --user lost it. The other root-run helpers in the go2rtc, nginx, and certsync scripts now use python3 -I too, so they never load user site-packages or PYTHON* variables.

* validate networking.listen values before rendering them into nginx config

ListenConfig and get_nginx_settings.py only checked that the text after the last colon parsed as an int, and tempio rendered the raw string into the listen directive, so a value like "5000; location /x/ { alias /; } #:5000" injected nginx directives. Both now go through parse_listen_address, which accepts only a port, IPv4:port, or [IPv6]:port with a 1 to 65535 port and rebuilds the value from the parsed parts. get_nginx_settings.py falls back to the default port on an invalid value so nginx still serves the safe-mode UI.

* tighten comments

* accept hostnames, wildcards, and padded values in networking.listen

The stricter parser broke localhost:5000, *:5000, and values with surrounding whitespace that the old int() parsing accepted. parse_listen_address now strips the value and accepts RFC 1123 hostnames and *, still rebuilding the rendered value from the parsed parts. The ListenConfig validator runs in before mode, because pydantic coerced true to port 1 while get_nginx_settings.py rejected it and fell back to 5000, so the auth internal port and nginx disagreed.

* always create go2rtc.yaml after removing it and don't let opt_in_out stop frigate

The go2rtc else-branch was only reachable when a regular file was planted between rm and the test, and then loaded that file as go2rtc's config. create_config.py now runs unconditionally and its exclusive create fails closed. opt_in_out runs after s6-svc -O, so a failure there was terminal under errexit.

* fall back to default listen ports when either is invalid or they collide

* keep valid listen values and refuse to start nginx when the ports collide

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

@@ -36,8 +36,8 @@ else
     lefile="/config/tls/fullchain.pem"
 fi
 
-tls_enabled=`python3 /usr/local/nginx/get_nginx_settings.py | jq -r .tls.enabled`
-listen_external_port=`python3 /usr/local/nginx/get_nginx_settings.py | jq -r .listen.external_port`
+tls_enabled=`python3 -I /usr/local/nginx/get_nginx_settings.py | jq -r .tls.enabled`
+listen_external_port=`python3 -I /usr/local/nginx/get_nginx_settings.py | jq -r .listen.external_port`
 
 while true
 do

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

@@ -11,30 +11,13 @@ if [[ "$(id -u)" -eq 0 ]]; then
     fi
 fi
 
-# /root survives s6-setuidgid and breaks cache writes after the drop; set
-# before opt_in_out so the opt-out marker lands where the service will look
-if [[ "$runs_as_root" -eq 0 ]]; then
-    export HOME=/config
-fi
-
-# detector runtimes installed at first start (pip install --user) live under
-# $HOME/.local; the dynamic loader only reads LD_LIBRARY_PATH at exec time
-export LD_LIBRARY_PATH="${LD_LIBRARY_PATH:+${LD_LIBRARY_PATH}:}${HOME}/.local/lib"
-export PATH="${PATH}:${HOME}/.local/bin"
-
-# opt out of openvino telemetry
-if [ -e /usr/local/bin/opt_in_out ]; then
-  /usr/local/bin/opt_in_out --opt_out > /dev/null 2>&1
-fi
-
-# Logs should be sent to stdout so that s6 can collect them
-
 # Tell S6-Overlay not to restart this service
 s6-svc -O .
 
+# Runs as root with root's HOME and LD_LIBRARY_PATH; -I skips user site-packages
 function set_libva_version() {
     local ffmpeg_path
-    ffmpeg_path=$(python3 /usr/local/ffmpeg/get_ffmpeg_path.py)
+    ffmpeg_path=$(python3 -I /usr/local/ffmpeg/get_ffmpeg_path.py)
     LIBAVFORMAT_VERSION_MAJOR=$("$ffmpeg_path" -version | grep -Po "libavformat\W+\K\d+")
     export LIBAVFORMAT_VERSION_MAJOR
 }
@@ -42,14 +25,32 @@ function set_libva_version() {
 echo "[INFO] Preparing Frigate..."
 set_libva_version
 
+# HOME=/root survives s6-setuidgid, so any run that is not root gets
+# HOME=/config explicitly. The runtime user owns /config, so these paths go
+# only to the service process, never to root. Detector runtimes installed at
+# first start (pip install --user) live under $HOME/.local.
+run_as=()
+runtime_home="${HOME}"
+if [[ "$runs_as_root" -eq 0 ]]; then
+    runtime_home=/config
+    if [[ "$(id -u)" -eq 0 ]]; then
+        run_as=(s6-setuidgid frigate)
+    fi
+fi
+run_as+=(env
+    "HOME=${runtime_home}"
+    "LD_LIBRARY_PATH=${LD_LIBRARY_PATH:+${LD_LIBRARY_PATH}:}${runtime_home}/.local/lib"
+    "PATH=${PATH}:${runtime_home}/.local/bin")
+
+# opt out of openvino telemetry; the marker lands under the service's HOME
+if [ -e /usr/local/bin/opt_in_out ]; then
+  "${run_as[@]}" /usr/local/bin/opt_in_out --opt_out > /dev/null 2>&1 || true
+fi
+
 echo "[INFO] Starting Frigate..."
 
 cd /opt/frigate || echo "[ERROR] Failed to change working directory to /opt/frigate"
 
 # Replace the bash process with the Frigate process, redirecting stderr to stdout
 exec 2>&1
-if [[ "$(id -u)" -ne 0 || "$runs_as_root" -eq 1 ]]; then
-    exec python3 -u -m frigate
-else
-    exec s6-setuidgid frigate python3 -u -m frigate
-fi
+exec "${run_as[@]}" python3 -u -m frigate

docker/main/rootfs/etc/s6-overlay/s6-rc.d/go2rtc/run

@@ -59,38 +59,33 @@ function get_ip_and_port_from_supervisor() {
 
 function set_libva_version() {
     local ffmpeg_path
-    ffmpeg_path=$(python3 /usr/local/ffmpeg/get_ffmpeg_path.py)
+    ffmpeg_path=$(python3 -I /usr/local/ffmpeg/get_ffmpeg_path.py)
     LIBAVFORMAT_VERSION_MAJOR=$("$ffmpeg_path" -version | grep -Po "libavformat\W+\K\d+")
     export LIBAVFORMAT_VERSION_MAJOR
 }
 
 set_libva_version
 
-if [[ -f "/dev/shm/go2rtc.yaml" ]]; then
-    echo "[INFO] Removing stale config from last run..."
-    rm /dev/shm/go2rtc.yaml
+# create_config.py creates the file exclusively and fails if anything
+# reappears at this path
+rm -f /dev/shm/go2rtc.yaml
+
+echo "[INFO] Preparing new go2rtc config..."
+
+if [[ -n "${SUPERVISOR_TOKEN:-}" ]]; then
+    # Running as a Home Assistant Add-on, infer the IP address and port
+    get_ip_and_port_from_supervisor
 fi
 
-if [[ ! -f "/dev/shm/go2rtc.yaml" ]]; then
-    echo "[INFO] Preparing new go2rtc config..."
-
-    if [[ -n "${SUPERVISOR_TOKEN:-}" ]]; then
-        # Running as a Home Assistant Add-on, infer the IP address and port
-        get_ip_and_port_from_supervisor
-    fi
-
-    python3 /usr/local/go2rtc/create_config.py
-else
-    echo "[WARNING] Unable to remove existing go2rtc config. Changes made to your frigate config file may not be recognized. Please remove the /dev/shm/go2rtc.yaml from your docker host manually."
-fi
+python3 -I /usr/local/go2rtc/create_config.py
 
 # HomeKit persistence. The helper is symlink-safe; hand off to go2rtc only when dropping.
 readonly homekit_config_path="/config/go2rtc_homekit.yml"
 if [[ "$(id -u)" -eq 0 && "$runs_as_root" -eq 0 ]]; then
-    python3 /usr/local/go2rtc/prepare_homekit.py "${homekit_config_path}" --chown
-    chown go2rtc:go2rtc /dev/shm/go2rtc.yaml 2>/dev/null || true
+    python3 -I /usr/local/go2rtc/prepare_homekit.py "${homekit_config_path}" --chown
+    chown -h go2rtc:go2rtc /dev/shm/go2rtc.yaml 2>/dev/null || true
 else
-    python3 /usr/local/go2rtc/prepare_homekit.py "${homekit_config_path}"
+    python3 -I /usr/local/go2rtc/prepare_homekit.py "${homekit_config_path}"
 fi
 
 readonly config_path="/config"

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

@@ -124,7 +124,7 @@ fi
 mkdir -p /etc/letsencrypt/www 2>/dev/null || true
 
 # nginx settings are read once; both templates consume them
-nginx_settings=$(python3 /usr/local/nginx/get_nginx_settings.py)
+nginx_settings=$(python3 -I /usr/local/nginx/get_nginx_settings.py)
 
 # build templates for optional FRIGATE_BASE_PATH environment variable
 echo "$nginx_settings" | \