vllm doesn't do it's own hostname gathering on this input (comes from CLI), the hostname itself is a kubernetes service. So zmq not doing a DNS lookup breaks what is expected to work upstream

   quay.io/aipcc/rhaiis/cuda-ubi9:3.2.2-175769903 

import zmq
import socket as sock
import platformprint("=== Environment Info ===")
print("ZMQ version:", zmq.zmq_version())
print("PyZMQ version:", zmq.pyzmq_version())
print("Platform:", platform.platform())
print("Python version:", platform.python_version())# Check hostname resolution
try:
    localhost_ip = sock.gethostbyname("localhost")
    print("localhost resolves to:", localhost_ip)
except Exception as e:
    print("localhost resolution failed:", str(e))print("\\n=== ZMQ Binding Tests ===")
ctx = zmq.Context()# Test localhost binding
socket = ctx.socket(zmq.REP)
try:
    socket.bind("tcp://localhost:0")
    port = socket.getsockopt(zmq.LAST_ENDPOINT).decode()
    print("✅ localhost bind succeeded on", port)
    localhost_success = True
except Exception as e:
    print("❌ localhost bind failed -", str(e))
    localhost_success = False
socket.close()# Test IP binding
socket2 = ctx.socket(zmq.REP)
try:
    socket2.bind("tcp://127.0.0.1:0")
    port2 = socket2.getsockopt(zmq.LAST_ENDPOINT).decode()
    print("✅ IP bind succeeded on", port2)
except Exception as e:
    print("❌ IP bind failed -", str(e))
socket2.close()# Test wildcard binding
socket3 = ctx.socket(zmq.REP)
try:
    socket3.bind("tcp://*:0")
    port3 = socket3.getsockopt(zmq.LAST_ENDPOINT).decode()
    print("✅ Wildcard bind succeeded on", port3)
except Exception as e:
    print("❌ Wildcard bind failed -", str(e))
socket3.close()ctx.term()
'''    cmd = ['podman', 'run', '--rm', '--entrypoint=', image, 'python3', '-c', test_script]    try:
        result = subprocess.run(cmd, capture_output=True, text=True, timeout=60)
        print(result.stdout)
        if result.stderr:
            print("STDERR:", result.stderr)
    except subprocess.TimeoutExpired:
        print("❌ Container test timed out")
    except Exception as e:
        print(f"❌ Error running container: {e}")    print()def main():
    print("Testing ZMQ hostname binding across images...")
    print()    images = [
        ("AIPCC Image (Expected to FAIL on localhost)", "quay.io/aipcc/rhaiis/cuda-ubi9:3.2.2-1757699034", True),
        ("WSEATON Image (Expected to SUCCEED on localhost)", "quay.io/wseaton/vllm:llmdnixlfix-01", False),
        ("LLM-D Image (Expected to SUCCEED on localhost)", "ghcr.io/llm-d/llm-d-dev:sha-b3f0b0d", False)
    ]    for name, image, should_fail in images:
        test_zmq_in_container(name, image, should_fail)if __name__ == "__main__":
    main()

 Fails on the AIPCC image

localhost bind succeeds