cv(runtime): attempt absolute dlopen of libGL.so.1 from standard paths before soname; add glob scanning with RTLD_GLOBAL

Author: z.murodov

nixpacks.toml

@@ -2,7 +2,7 @@
 # Ensure Python is present for Nixpacks Python phase, plus native deps for OpenCV/MediaPipe
 nixPkgs = ['python311', 'libGL', 'libglvnd', 'pkg-config', 'glib', 'zlib', 'mesa', 'xorg.libX11', 'xorg.libXext', 'xorg.libXrender']
 cmds = [
-  'apt-get update -y && DEBIAN_FRONTEND=noninteractive apt-get install -y libgl1 libglvnd0 libglx-mesa0 libgl1-mesa-dri libglib2.0-0 libxext6 libxrender1 libxfixes3 libsm6 libxcb1 libxau6 libxdmcp6 libglx0'
+  'apt-get update -y && DEBIAN_FRONTEND=noninteractive apt-get install -y libgl1 libglvnd0 libglx-mesa0 libgl1-mesa-dri libglib2.0-0 libxext6 libxrender1 libxfixes3 libsm6 libxcb1 libxau6 libxdmcp6 libglx0 libx11-6 libx11-xcb1 libxrandr2 libxxf86vm1 libxdamage1 libxshmfence1 libdrm2 libexpat1'
 ]
 
 [start]

src/cv/video_processor.py

@@ -3,6 +3,7 @@
 import asyncio
 import os
 import ctypes
+import glob
 
 # Force CPU path for MediaPipe in headless servers (Railway)
 os.environ.setdefault("MEDIAPIPE_DISABLE_GPU", "1")
@@ -21,13 +22,37 @@
 os.environ["LD_LIBRARY_PATH"] = _existing_ld
 
 # Try to preload libGL to avoid 'libGL.so.1: cannot open shared object file'
-for _lib in ("libGL.so.1", "libGL.so"):
+# 1) Absolute candidates in common locations
+_gl_candidates = [
+    "/usr/lib/x86_64-linux-gnu/libGL.so.1",
+    "/lib/x86_64-linux-gnu/libGL.so.1",
+]
+for pattern in (
+    "/usr/lib/x86_64-linux-gnu/libGL.so*",
+    "/lib/x86_64-linux-gnu/libGL.so*",
+):
+    _gl_candidates.extend(glob.glob(pattern))
+
+_loaded_gl = False
+for path in _gl_candidates:
     try:
-        ctypes.CDLL(_lib)
-        break
+        if os.path.exists(path):
+            ctypes.CDLL(path, mode=getattr(ctypes, "RTLD_GLOBAL", 0))
+            _loaded_gl = True
+            break
     except OSError:
         continue
 
+# 2) Fallback to sonames if absolute paths failed
+if not _loaded_gl:
+    for _lib in ("libGL.so.1", "libGL.so"):
+        try:
+            ctypes.CDLL(_lib, mode=getattr(ctypes, "RTLD_GLOBAL", 0))
+            _loaded_gl = True
+            break
+        except OSError:
+            continue
+
 # Try to import computer vision libraries
 try:
     import cv2