为什么httpd容器立即退出而在Docker中没有任何错误 [英] Why httpd container exits immediately without any error in Docker

问题描述

我是Docker的新手。我的Dockerfile（从教程中获得）是：

  FROM ubuntu 
 
 ENV DEBIAN_FRONTEND非交互式
 
运行apt-get更新\ 
&& apt-get install -y --no-install-recommends apache2 \ 
 libapache2-mod-jk 
 VOLUME [ / var / log / apache2] 
 RUN echo'ServerName localhost' >> /etc/apache2/apache2.conf 
 EXPOSE 80443 
 
 ENTRYPOINT [ apache2ctl，-D， FOREGROUND] 
  

我给了 docker build -t mg：httpd apache\ 。没有错误。

 λdocker images 
存储标签图像ID大小已增加
 mg httpd 262d7a4f85fc大约一个小时之前248MB 
  

docker run -it mg：httpd

没有错误，但光标会立即返回命令提示符。在浏览器中进入 http：// localhost / 时得到无法连接。

 λdocker ps -a 
容器ID图像命令创建的状态端口
 600231bbd461 mg：httpd apache2ctl -D FOR ... 2分钟前退出（0）2分钟前
  

docker日志为空

 λDocker事件
 2017-09-08T15：26：10.726720800 + 05：30容器创建5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157（image = mg：httpd，name = zealous_ritchie）
 2017-09-08T15：26：10.740310700 + 05：30容器附加5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157（image = mg：httpd，name = zealous_ritchie）$ b：b 2017-09-08 ：11.035777100 + 05：30网络连接2b8829b336575a2aa2210f55105d793e8f1b196d51845d38d3dc8ff322af6143（容器= 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157，name = bridge，$ = b：26：09 + 05：T09：$ 08：b：b：type：-09-05） 30卷装入e8421cbd867fca04f0dd3ee6da815c59cad5fc32c5a427710d144213b43caa26（容器= 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157，目的地=的/ var /数/ apache2的，驱动器=本地，传播=，读/写=真）
 2017-09-08T15：26：11.548736900 + 05：30开始容器5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157（image = mg：httpd，name = zealous_ritchie）
 2017-09-08T15：26：11.573272300 + 05：30容器大小调整5325b79abe1988312952629165551c169a8bdc3fbe6177（1783） ）
 2017-09-08T15：26：12.733164900 + 05：30容器模具5325b79abe1988312952629629165551c169a8bdc3fbe6e473cf0177859db7c0157（exitCode = 0，image = mg：httpd，name = zealous_ritchie）
 2017-09-08T15：26：13.227455 05:30网络断开连接2b8829b336575a2aa2210f55105d793e8f1b196d51845d38d3dc8ff322af6143（容器= 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157，名称=网桥，类型=网桥）
 2017：18：00 3.306885700 + 05：30卸下卷e8421cbd867fca04f0dd3ee6da815c59cad5fc32c5a427710d144213b43caa26（container = 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db  
 $ b>原因？未启动容器时如何查看apache log\conf文件？ 
解决方案
因此，您的Web服务器不是作为前台进程启动的，这就是为什么立即停止容器的原因。
 
 
 
我认为您应该更改
  ENTRYPOINT [ apache2ctl， -D，  FOREGROUND] 
  
至
  CMD [ apache2ctl，-D， FOREGROUND] 
  
因为您要在挂载容器时运行该命令。
 
 
 
  ENTRYPOINT 指令声明可执行文件，用于执行 CMD 。
  ENTRYPOINT [ apache2ctl，  -D， FOREGROUND] 
导致：
 $ apache2ctl -D FOREGROUND<来自运行命令行或CMD指令的命令> 
  
 来自Ubuntu映像的默认命令我可以找到的是 / bin / bash  。 
因此，当您使用以下命令运行容器时：
  docker run -it mg：httpd 
  
执行的结果命令将是：
  $ apache2ctl -D FOREGROUND / bin / bash 
  
显然没有多大意义。我建议浏览那 
 
 
经过上述更改后，它看起来像这样：
 （默认）ENTRYPOINT [ / bin / sh， -c] 
 CMD [ apache2ctl， -D， FOREGROUND] 
结果如下：
 $ / bin / sh -c apache2ctl -D FOREGROUND 
  
 
I am new to Docker. My Dockerfile (got from a tutorial) is:
FROM ubuntu

ENV DEBIAN_FRONTEND noninteractive

RUN apt-get update \
&& apt-get install -y --no-install-recommends apache2 \
                        libapache2-mod-jk
VOLUME ["/var/log/apache2"]
RUN echo 'ServerName localhost' >> /etc/apache2/apache2.conf
EXPOSE 80 443

ENTRYPOINT ["apache2ctl", "-D", "FOREGROUND"]
I gave docker build -t mg:httpd apache\. No errors.
λ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED                SIZE
mg                  httpd               262d7a4f85fc        About an hour ago      248MB
docker run -it mg:httpd

No errors, but the cursor returns to command prompt immediately. Getting Unable to connect on taking http://localhost/ in browser. 
λ docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                         PORTS                
600231bbd461        mg:httpd            "apache2ctl -D FOR..."   2 minutes ago       Exited (0) 2 minutes ago             
docker logs is empty 
λ docker events
2017-09-08T15:26:10.726720800+05:30 container create 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157 (image=mg:httpd, name=zealous_ritchie)
2017-09-08T15:26:10.740310700+05:30 container attach 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157 (image=mg:httpd, name=zealous_ritchie)
2017-09-08T15:26:11.035777100+05:30 network connect 2b8829b336575a2aa2210f55105d793e8f1b196d51845d38d3dc8ff322af6143 (container=5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157, name=bridge, type=bridge)
2017-09-08T15:26:11.090873500+05:30 volume mount e8421cbd867fca04f0dd3ee6da815c59cad5fc32c5a427710d144213b43caa26 (container=5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157, destination=/var/log/apache2, driver=local, propagation=, read/write=true)
2017-09-08T15:26:11.548736900+05:30 container start 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157 (image=mg:httpd, name=zealous_ritchie)
2017-09-08T15:26:11.573272300+05:30 container resize 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157 (height=41, image=mg:httpd, name=zealous_ritchie, width=168)
2017-09-08T15:26:12.733164900+05:30 container die 5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157 (exitCode=0, image=mg:httpd, name=zealous_ritchie)
2017-09-08T15:26:13.227455500+05:30 network disconnect 2b8829b336575a2aa2210f55105d793e8f1b196d51845d38d3dc8ff322af6143 (container=5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157, name=bridge, type=bridge)
2017-09-08T15:26:13.306885700+05:30 volume unmount e8421cbd867fca04f0dd3ee6da815c59cad5fc32c5a427710d144213b43caa26 (container=5325b79abe1988312952629165551c169a8bdc3fbe6e473cf0177859db7c0157, driver=local)
what could be the reason?   How can I look into the apache log\conf files when the container is not started?            
解决方案
So your Webserver is not startet as a foreground process, that is why the container is stopped immediately.

I think you should change
ENTRYPOINT ["apache2ctl", "-D", "FOREGROUND"]
to 
CMD ["apache2ctl", "-D", "FOREGROUND"]
Because you want that command to run when the container is mounted.

The ENTRYPOINT directive declares the executable which is used to execute the CMD.
ENTRYPOINT ["apache2ctl", "-D", "FOREGROUND"]
results in:
$  apache2ctl -D FOREGROUND <command either from the run command line or the CMD directive>
The default command from Ubuntu image I could find is /bin/bash.
So when you run the container using:
docker run -it mg:httpd
the resulting command that is executed will be:
$  apache2ctl -D FOREGROUND /bin/bash
what obviously does not make much sense. I would recommend to go over that post, it explains the details very well.

After the change described above it will look like that:
(default) ENTRYPOINT ["/bin/sh", "-c"]
CMD ["apache2ctl", "-D", "FOREGROUND"]
what results in:
$  /bin/sh -c "apache2ctl -D FOREGROUND"


                        
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