python - 尽管 shell 脚本抛出 [Errno 111] 连接被拒绝，但在 Docker 启动时使用 TCP 服务器执行 python3 脚本

Question

我开发了一些 Python3 脚本来在 Standalone Selenium Chrome 之上运行与 TCP 服务器的图像来执行一些进程，该进程收集测试期间创建的一些信息，并且这些信息位于容器内。每当我需要启动 python3 进程时，我都会通过 TCP 客户端连接到它，发送一些命令，然后 python3 脚本就会执行我需要它执行的操作。
在我的 dockerfile 上，我安装了 pip3 和我需要的所有内容，然后复制了我需要的所有脚本，如果我手动访问 docker 容器，并且手动启动 python3 脚本，一切都会完美运行，如下所示:

docker exec -it selc bash
cd /home/seluser/python/
sudo nohup python3 myscript.py &

这成功地在后台启动了我的 python3 脚本，并且运行得很好

seluser@24d2713db5f1:~/python$ sudo nohup python3 myscript.py &
[1] 71
seluser@24d2713db5f1:~/python$ nohup: ignoring input and appending output to 'nohup.out'

但是，我希望每当启动容器时自动执行此脚本，但我无法成功执行此操作。当我运行容器时，我在容器日志中收到 ConnectionRefusedError: [Errno 111] Connection returned 错误。下面是我的 dockerfile

FROM selenium/standalone-chrome-debug

USER root

RUN apt-get update &&\
    apt-get upgrade -y &&\
    apt-get install python3-pip -y &&\
    apt-get install dos2unix -y &&\
    pip3 install pynput &&\
    pip3 install azure.storage.blob &&\
    apt-get install vim -y

USER seluser

EXPOSE 9871

RUN mkdir -p /home/seluser/upload &&\
    mkdir -p /home/seluser/python &&\
    mkdir -p /home/seluser/logs &&\
    mkdir -p /home/seluser/debug

ADD /python /home/seluser/python

USER root

COPY entry_point.sh /opt/bin/entry_point.sh

RUN dos2unix /opt/bin/entry_point.sh &&\
    chmod a+x /opt/bin/entry_point.sh

USER seluser

下面是我从 selenium github 获取的 shell 脚本entry_point.sh，只需修改即可运行我的脚本

#!/usr/bin/env bash

if ! whoami &> /dev/null; then
  if [ -w /etc/passwd ]; then
    echo "${USER_NAME:-default}:x:$(id -u):0:${USER_NAME:-default} user:${HOME}:/sbin/nologin" >> /etc/passwd
  fi
fi

/usr/bin/supervisord --configuration /etc/supervisord.conf &

SUPERVISOR_PID=$!

function shutdown {
    echo "Trapped SIGTERM/SIGINT/x so shutting down supervisord..."
    kill -s SIGTERM ${SUPERVISOR_PID}
    wait ${SUPERVISOR_PID}
    echo "Shutdown complete"
}

echo "Starting script PYTHON3"
nohup python3 /home/seluser/python/myscript.py &
echo "script PYTHON3 started"

trap shutdown SIGTERM SIGINT
wait ${SUPERVISOR_PID}

这是我启动的 myscript.py

import asyncio
import logging
import time

from servico.myserver import myServer
from auxiliar.objlog import ObjLog
from auxiliar.objip import ObjIp

logger = ObjLog().executar()

logger.debug("Starting execution")

time.sleep(3)

logger.debug("Getting connection")

loop = asyncio.get_event_loop()
stream_server = myServer(loop)
# ip = ObjIp().executar()
# logger.debug('IP:' + ip)

coro_server = asyncio.start_server(
    stream_server.server_handler,
    '0.0.0.0',
    9871,
    loop=stream_server.loop
)

server = loop.run_until_complete(coro_server)

logger.debug('Pre-execution')
logger = ObjLog().executar()
logger.debug('Listening:' + str(server.sockets[0].getsockname()))

try:
    loop.run_forever()
except KeyboardInterrupt:
    pass

print('Closing Server')
server.close()
loop.run_until_complete(server.wait_closed())
loop.close()

我使用此 docker run 命令启动容器

docker run --name selc --detach --rm -p 4444:4444 -p 5900:5900 -p 9871:9871 mydocker/selenium-debug-chrome:latest

启动容器时得到的日志如下

λ  docker logs selc                                                                                                     
Iniciando script PYTHON3                                                                                                
script PYTHON3 iniciado                                                                                                 
Traceback (most recent call last):                                                                                      
  File "/usr/local/lib/python3.6/dist-packages/Xlib/support/unix_connect.py", line 119, in get_socket                   
    s = _get_unix_socket(address)                                                                                       
  File "/usr/local/lib/python3.6/dist-packages/Xlib/support/unix_connect.py", line 98, in _get_unix_socket              
    s.connect(address)                                                                                                  
ConnectionRefusedError: [Errno 111] Connection refused                                                                  

During handling of the above exception, another exception occurred:                                                     

Traceback (most recent call last):                                                                                      
  File "/usr/local/lib/python3.6/dist-packages/Xlib/support/unix_connect.py", line 123, in get_socket                   
    s = _get_tcp_socket(host, dno)                                                                                      
  File "/usr/local/lib/python3.6/dist-packages/Xlib/support/unix_connect.py", line 93, in _get_tcp_socket               
    s.connect((host, 6000 + dno))                                                                                       
ConnectionRefusedError: [Errno 111] Connection refused                                                                  

During handling of the above exception, another exception occurred:                                                     

Traceback (most recent call last):                                                                                      
  File "/home/seluser/python/my.py", line 5, in <module>                                                      
    from servico.myserver import myServer                                                           
  File "/home/seluser/python/servico/myserver.py", line 7, in <module>                                        
    from servico.tarefas.download_pdf import DownloadPdf                                                                
  File "/home/seluser/python/servico/tarefas/download_pdf.py", line 5, in <module>                                      
    from pynput.keyboard import Key, Controller                                                                         
  File "/usr/local/lib/python3.6/dist-packages/pynput/__init__.py", line 23, in <module>                                
    from . import keyboard                                                                                              
  File "/usr/local/lib/python3.6/dist-packages/pynput/keyboard/__init__.py", line 49, in <module>                       
    from ._xorg import KeyCode, Key, Controller, Listener                                                               
  File "/usr/local/lib/python3.6/dist-packages/pynput/keyboard/_xorg.py", line 39, in <module>                          
    from pynput._util.xorg import (                                                                                     
  File "/usr/local/lib/python3.6/dist-packages/pynput/_util/xorg.py", line 40, in <module>                              
    _check()                                                                                                            
  File "/usr/local/lib/python3.6/dist-packages/pynput/_util/xorg.py", line 38, in _check                                
    display = Xlib.display.Display()                                                                                    
  File "/usr/local/lib/python3.6/dist-packages/Xlib/display.py", line 89, in __init__                                   
    self.display = _BaseDisplay(display)                                                                                
  File "/usr/local/lib/python3.6/dist-packages/Xlib/display.py", line 71, in __init__                                   
    protocol_display.Display.__init__(self, *args, **keys)                                                              
  File "/usr/local/lib/python3.6/dist-packages/Xlib/protocol/display.py", line 89, in __init__                          
    self.socket = connect.get_socket(name, protocol, host, displayno)                                                   
  File "/usr/local/lib/python3.6/dist-packages/Xlib/support/connect.py", line 87, in get_socket
    return mod.get_socket(dname, protocol, host, dno)
  File "/usr/local/lib/python3.6/dist-packages/Xlib/support/unix_connect.py", line 127, in get_socket
    raise error.DisplayConnectionError(dname, str(val))
Xlib.error.DisplayConnectionError: Can't connect to display ":99.0": [Errno 111] Connection refused
2019-03-16 14:00:59,881 INFO Included extra file "/etc/supervisor/conf.d/selenium-debug.conf" during parsing
2019-03-16 14:00:59,881 INFO Included extra file "/etc/supervisor/conf.d/selenium.conf" during parsing
2019-03-16 14:00:59,885 INFO supervisord started with pid 7
2019-03-16 14:01:00,887 INFO spawned: 'xvfb' with pid 13
2019-03-16 14:01:00,888 INFO spawned: 'fluxbox' with pid 14
2019-03-16 14:01:00,890 INFO spawned: 'vnc' with pid 15
2019-03-16 14:01:00,891 INFO spawned: 'selenium-standalone' with pid 16
2019-03-16 14:01:01,016 INFO success: xvfb entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)2019-03-16 14:01:01,016 INFO success: fluxbox entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
2019-03-16 14:01:01,016 INFO success: vnc entered RUNNING state, process has stayed up for > than 0 seconds (startsecs) 2019-03-16 14:01:01,017 INFO success: selenium-standalone entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
14:01:01.332 INFO [GridLauncherV3.parse] - Selenium server version: 3.141.59, revision: e82be7d358
14:01:01.429 INFO [GridLauncherV3.lambda$buildLaunchers$3] - Launching a standalone Selenium Server on port 4444
2019-03-16 14:01:01.489:INFO::main: Logging initialized @570ms to org.seleniumhq.jetty9.util.log.StdErrLog
14:01:01.822 INFO [WebDriverServlet.<init>] - Initialising WebDriverServlet
14:01:01.941 INFO [SeleniumServer.boot] - Selenium Server is up and running on port 4444    

如果我通过 bash 手动连接到它，并按照我指出的方式启动它，它就可以正常工作。它只是在启动时不起作用。

为什么我会收到此错误？还有其他方法可以在容器启动后自动启动 python3 脚本吗？非常感谢您的帮助。

编辑

基于基础镜像，它已经有一个 shell 脚本的入口点。看看docker检查我可以看到它。

λ  docker inspect selc
[
    {
        "Id": "24d2713db5f13be0c69479a27f6ea4c943d194edbe3b2fa303aaac966639694e",
        "Created": "2019-03-16T14:31:43.6236537Z",
        "Path": "/opt/bin/entry_point.sh",
        "Args": [],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 34191,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2019-03-16T14:31:44.2388239Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },

我不想改 rebase 础图像工作的机制，只是稍微调整一下以尝试使用现有代码执行我的脚本。但我对想法持开放态度，因为我不知道该怎么做。

Answer 1

由于您有 supervisord，更好的方法是通过它运行 python 脚本，而不是使用 nohup。因此，创建一个类似 myscript.conf

的文件

[program:myscript]
command=/usr/bin/python3 /home/seluser/python/myscript.py
autostart=true
autorestart=true
startretries=3
user=seluser

在你的 Dockerfile 中替换以下行:

COPY entry_point.sh /opt/bin/entry_point.sh

RUN dos2unix /opt/bin/entry_point.sh &&\
    chmod a+x /opt/bin/entry_point.sh

下面这个:

According to the main configuration file of docker-selenium, any additional config should be add to /etc/supervisor/conf.d/

COPY myscript.conf /etc/supervisor/conf.d/

并且不需要修改入口点脚本，因为我们用supervisord配置文件替换了nohup