app2/.vscode/launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [

        
        {
            "name": "Listen for XDebug",
            "type": "php",
            "request": "launch",
            "port": 9000,
            "pathMappings": { // "容器中对应的项目地址": "本机项目地址" // 绝对路径 
                "/app/":"/var/www/app2"}

        },
        {
            "name": "Launch currently open script",
            "type": "php",
            "request": "launch",
            "program": "${file}",
            "cwd": "${fileDirname}",
            "port": 9000
        }
    ]
}