Port çakışmaları ve proses ağaçları: PortTree ile soket denetimi

# EADDRINUSE runtime crash during server boot:
Error: listen EADDRINUSE: address already in use :::3000
    at Server.setupListenHandle [as _listen2] (node:net:1904:16)
    at listenInCluster (node:net:1961:12)
    at Server.listen (node:net:2063:7)

# The classic blind kill pattern and why it fails:
kill -9 41280
# Socket remains occupied or child respawns under supervisor PID 41200

# Linux /proc parsing & Windows ctypes bindings in PortTree:
from ctypes import Structure, c_ulong, sizeof, windll, byref

class MIB_TCPROW_OWNER_PID(Structure):
    _fields_ = [
        ("dwState", c_ulong),
        ("dwLocalAddr", c_ulong),
        ("dwLocalPort", c_ulong),
        ("dwRemoteAddr", c_ulong),
        ("dwRemotePort", c_ulong),
        ("dwOwningPid", c_ulong),
    ]

# Zero third-party C-extensions or compilation wheels required.

# Install PortTree from PyPI (zero dependencies):
python -m pip install porttree==1.0.0

# Inspect which process owns port 3000:
porttree 3000

# View full process hierarchy from socket owner up to supervisor:
porttree 3000 --tree

# Gracefully terminate the process tree occupying the port:
porttree 3000 --kill

# Structured JSON output for CI pipeline assertions:
porttree 3000 --format json

# GitHub Actions workflow: Pre-flight port availability assertion
- name: Verify clean port state for test runner
  run: |
    python -m pip install porttree==1.0.0
    # Returns exit code 0 if port 3000 is free, 1 if occupied
    porttree 3000 --check-free || {
      echo "Port 3000 is unexpectedly held prior to integration tests"
      porttree 3000 --format json
      exit 1
    }