PHP Xdebug超时连接到客户端（Docker，VSCode，Ubuntu）

Question

I'm trying to troubleshoot a Docker/PHP-Xdebug/VSCode environment on Ubuntu that has been working very well for the last few months. And now xdebug have trouble connecting to the client.

After entering the Docker with docker exec --tty --interactive bw bash

php -v

returns

PHP 7.2.14 (cli) (built: Feb  6 2019 05:10:24) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Xdebug v2.7.2, Copyright (c) 2002-2019, by Derick Rethans

while php -m -c lists Xdebug in the [Zend Modules] section.

Here is the .ini part

[xdebug]
xdebug.default_enable = 1
xdebug.remote_enable = 1
xdebug.remote_autostart = 1
xdebug.remote_connect_back = 1
xdebug.idekey = VSCODE
xdebug.remote_handler = "dbgp"
xdebug.remote_port = 9000
xdebug.remote_log=/var/log/apache2/xdebug.log
xdebug.remote_timeout = 500

Eveything in there is reflected accordingly in phpinfo() output.

docker-compose.yml

version: "3.1"
services:
  webserver:
    build: docker/apache
    container_name: bw
    volumes:
      - .:/var/www/html
    ports:
     - "8000:80"
    expose:
     - "9000"
    restart: always

launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Listen for XDebug",
            "type": "php",
            "request": "launch",
            "port": 9000,
            "log":true,
            "pathMappings": {
            "/var/www/html": "${workspaceRoot}/",
            }
        },
        {
            "name": "Launch currently open script",
            "type": "php",
            "request": "launch",
            "program": "${file}",
            "cwd": "${fileDirname}",
            "port": 9000
        }    ]
}

This is the tail of the xdebug.log

[156] Log opened at 2019-08-05 19:39:58
[156] I: Checking remote connect back address.
[156] I: Checking header 'HTTP_X_FORWARDED_FOR'.
[156] I: Checking header 'REMOTE_ADDR'.
[156] I: Remote address found, connecting to 172.18.0.1:9000.
[156] E: Time-out connecting to client (Waited: 500 ms). :-(
[156] Log closed at 2019-08-05 19:39:59

I strongly suspect my lack of Docker knowledge is the problem to make this work again.

Any help would be appreciated.

Answer 1

Problem was with the firewall of the host. Can't really tell how/why the rule disappeared.
I was probing the port with telnet the wrong way around and that led me thinking the firewall was letting traffic through. ufw allow from any to any port 9000 proto tcp on the host did in fact re-establish everything.