launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": ".NET Core Docker Attach",
            "type": "coreclr",
            "request": "attach",
            "processId": "1",

            "pipeTransport": {
                "pipeProgram": "sh",
                "pipeArgs": [ 
                    "-c",
                    "docker exec -i $(docker ps -q -f publish=6000) ${debuggerCommand}"
                ],
                "debuggerPath": "/vsdbg/vsdbg",
                "pipeCwd": "${workspaceFolder}",
            },

            "windows": {
                "pipeTransport": {
                    "pipeProgram": "powershell",
                    "pipeArgs": [
                        "-c",
                        "docker exec -i $(docker ps -q -f publish=6000) ${debuggerCommand}"
                    ],
                    "debuggerPath": "/vsdbg/vsdbg",
                    "pipeCwd": "${workspaceFolder}",
                }
            },

            "sourceFileMap": {
                "/var/task": "${workspaceFolder}"
            }
        }
    ]
}