feat: Python PID 1 wrapper for HF runtime log API compatibility

HF's log API doesn't capture bash stdout/stderr from Docker containers.
Use a Python process as PID 1 that tails /var/log/huggingrun.log and
prints to stdout/stderr. All scripts write to the logfile, Python
PID 1 echoes them for HF to capture.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -49,7 +49,7 @@ COPY ubuntu-server/ws-ssh-bridge.py /opt/ws-ssh-bridge.py
 COPY ubuntu-server/git_sync_daemon.py /opt/git_sync_daemon.py
 COPY ubuntu-server/start-server.sh /opt/start-server.sh
 COPY scripts /scripts
-RUN chmod +x /scripts/entrypoint.sh /opt/start-server.sh
+RUN chmod +x /scripts/entrypoint.sh /scripts/entrypoint_wrapper.py /opt/start-server.sh
 
 ENV PERSIST_PATH=/data
 ENV PYTHONUNBUFFERED=1
@@ -58,4 +58,6 @@ ENV SSH_PORT=2222
 
 # Run as root (needed for: apt install persistence, bind mounts, sshd)
 EXPOSE 7860
-ENTRYPOINT ["/scripts/entrypoint.sh"]
+# Python PID 1: HF log API captures Python stdout/stderr reliably
+# The wrapper tails /var/log/huggingrun.log → stdout/stderr for HF to capture
+ENTRYPOINT ["python3", "/scripts/entrypoint_wrapper.py"]

scripts/entrypoint_wrapper.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+"""
+Python PID 1 wrapper for HF Spaces log compatibility.
+HF's runtime log API captures Python stdout/stderr better than bash.
+This wrapper stays as PID 1, runs entrypoint.sh as a child,
+and mirrors all log output to stdout/stderr.
+"""
+import subprocess
+import sys
+import os
+import signal
+import time
+import threading
+
+LOGFILE = "/var/log/huggingrun.log"
+
+def log(msg):
+    """Write to stdout, stderr, and logfile simultaneously."""
+    line = f"{msg}\n"
+    sys.stdout.write(line)
+    sys.stdout.flush()
+    sys.stderr.write(line)
+    sys.stderr.flush()
+    try:
+        with open(LOGFILE, "a") as f:
+            f.write(line)
+    except Exception:
+        pass
+
+def tail_logfile():
+    """Background thread: tail the logfile and print new lines to stdout/stderr."""
+    # Wait for logfile to exist
+    while not os.path.exists(LOGFILE):
+        time.sleep(0.5)
+
+    with open(LOGFILE, "r") as f:
+        # Skip to current end
+        f.seek(0, 2)
+        while True:
+            line = f.readline()
+            if line:
+                line = line.rstrip("\n")
+                sys.stdout.write(f"{line}\n")
+                sys.stdout.flush()
+                sys.stderr.write(f"{line}\n")
+                sys.stderr.flush()
+            else:
+                time.sleep(0.3)
+
+if __name__ == "__main__":
+    log("========================================")
+    log("[wrapper] HuggingRun Python PID 1 wrapper")
+    log(f"[wrapper] PID={os.getpid()}, Date={time.strftime('%Y-%m-%d %H:%M:%S UTC', time.gmtime())}")
+    log(f"[wrapper] Python {sys.version.split()[0]}")
+    log("========================================")
+
+    # Start background tailer: reads logfile and echos to stdout/stderr
+    # This ensures all log output (from bash scripts, python daemons) gets
+    # printed through PID 1's stdout/stderr for HF to capture
+    tailer = threading.Thread(target=tail_logfile, daemon=True)
+    tailer.start()
+
+    # Run entrypoint.sh as child process
+    proc = subprocess.Popen(
+        ["/bin/bash", "/scripts/entrypoint.sh"],
+        stdout=subprocess.DEVNULL,  # entrypoint writes to logfile
+        stderr=subprocess.DEVNULL,  # entrypoint writes to logfile
+    )
+
+    # Forward signals to child
+    def forward_signal(sig, frame):
+        log(f"[wrapper] Signal {sig} received, forwarding to child PID={proc.pid}")
+        try:
+            proc.send_signal(sig)
+        except ProcessLookupError:
+            pass
+
+    signal.signal(signal.SIGTERM, forward_signal)
+    signal.signal(signal.SIGINT, forward_signal)
+
+    # Wait for child to exit
+    rc = proc.wait()
+    log(f"[wrapper] Child exited with code {rc}")
+    sys.exit(rc)