如何在运行中的docker容器上执行命令？ [英] How to execute a command on a running docker container?

问题描述

我有一个容器运行hadoop。我有另一个Docker文件，其中包含Map-Reduce作业命令，如创建输入目录，处理默认示例，显示输出。第二个文件的基本图像是由第一个docker文件创建的hadoop_image。

编辑

Dockerfile - 对于hadoop

  #base image是ubuntu：precise 
 #cdh安装
 #hadoop -0.20-conf-pseudo安装
 #CMD to start-all.sh 
  

all.sh

 ＃启动/etc/init.d/hadoop-*下的所有服务
  

由此创建的hadoop基本图像。

Dockerfile2

  #base image was hadoop 
＃flume-ng and flume-ng agent installation 
 #conf change 
＃ flume -start.sh 
  

flume-start.sh

  #start flume services 
  

我正在运行容器分开。工作正常但是如果我运行

  docker run -it flume_service 
  

它启动flume并显示一个bash提示符[/ bin / bash是flume-start.sh的最后一行]。我执行

  hadoop fs -ls / 
  

在第二个运行容器中，我收到以下错误

ls：从514fa776649a / 172.17.5.188调用到localhost： 8020连接异常失败：java.net.ConnectException：Connection refused;有关详细信息，请参阅： http://wiki.apache.org/hadoop/ConnectionRefused

我知道我收到此错误是因为hadoop服务尚未启动。但我的怀疑是我的第一个容器正在运行。我用这个作为第二个容器的基础图像。那为什么我得到这个错误？是否需要在flume contianer的hdfs-site.xml文件中更改任何内容？

伪分布式模式的安装。

任何建议？

或者我需要暴露任何端口，像这样吗？如果是，请提供一个例子

编辑2

  iptables -t nat -L -n 
  

我看到

  sudo iptables -t nat -L -n 
链条PREROUTING（policy ACCEPT）
 target prot opt source destination 
 DOCKER all  -  0.0.0.0/0 0.0.0.0/0 ADDRTYPE match dst- 
 
 Chain POSTROUTING（policy ACCEPT）
 target prot opt source destination 
 MASQUERADE tcp  - 192.168.122.0/24！192.168.122.0/24 masq ports：1024-6 
 MASQUERADE udp  -  192.168.122.0/24！192.168.122.0/24 masq ports：1024-6 
 MASQUERADE all  - 192.168.122.0/24！192.168.122.0/24 
 MASQUERADE全部 -  172.17.0.0/16 0.0.0.0/0 
 
链式OUTPUT（policy ACCEPT）
 target prot opt源目的地
 DOCKER全部 -  0.0.0.0/0！127.0.0.0/8 ADDRTYPE匹配dst- 
 
链DOCKER（2参考）
目标prot opt源目的地
  

它是在docker @ domian。不在容器内。

编辑
请参阅surazj'answer

解决方案

我想我遇到了同样的问题。我不能在docker1中通过hadoop命令start-all.sh启动hadoop namenode和datanode。

这是因为它通过hadoop-daemons.sh启动namenode和datanode，但它失败了。真正的问题是ssh在码头工作中不起作用。

所以，您可以执行

• 解决方案1）：
  
  将所有术语daemons.sh替换为start-dfs.sh中的daemon.sh，
  运行start-dfs.sh




• （解决方案2）：do
  

  
  
  

  $ HADOOP_PREFIX / sbin / hadoop-daemon.sh start datanode
  $ HADOOP_PREFIX / sbin / hadoop-daemon.sh start namenode

您可以看到datanode和namenode正常工作命令jps

问候。

I have a container running hadoop. I have another docker file which contains Map-Reduce job commands like creating input directory, processing a default example, displaying output. Base image for the second file is hadoop_image created from first docker file.

EDIT

Dockerfile - for hadoop

 #base image is ubuntu:precise
 #cdh installation
 #hadoop-0.20-conf-pseudo installation
 #CMD to start-all.sh

start-all.sh

 #start all the services under /etc/init.d/hadoop-*

hadoop base image created from this.

Dockerfile2

 #base image is hadoop
 #flume-ng and flume-ng agent installation
 #conf change
 #flume-start.sh

flume-start.sh

#start flume services

I am running both containers separately. It works fine. But if i run

docker run -it flume_service

it starts flume and show me a bash prompt [/bin/bash is the last line of flume-start.sh]. The i execute

hadoop fs -ls /

in the second running container, i am getting the following error

ls: Call From 514fa776649a/172.17.5.188 to localhost:8020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused

I understand i am getting this error because hadoop services are not started yet. But my doubt is my first container is running. I am using this as base image for second container. Then why am i getting this error? Do i need to change anything in hdfs-site.xml file on flume contianer?

Pseudo-Distributed mode installation.

Any suggestions?

Or Do i need to expose any ports and like so? If so, please provide me an example

EDIT 2

  iptables -t nat -L -n

I see

  sudo iptables -t nat -L -n
  Chain PREROUTING (policy ACCEPT)
  target     prot opt source               destination
  DOCKER     all  --  0.0.0.0/0            0.0.0.0/0           ADDRTYPE match dst-

  Chain POSTROUTING (policy ACCEPT)
  target     prot opt source               destination
  MASQUERADE  tcp  --  192.168.122.0/24    !192.168.122.0/24    masq ports: 1024-6
  MASQUERADE  udp  --  192.168.122.0/24    !192.168.122.0/24    masq ports: 1024-6
  MASQUERADE  all  --  192.168.122.0/24    !192.168.122.0/24
  MASQUERADE  all  --  172.17.0.0/16        0.0.0.0/0

  Chain OUTPUT (policy ACCEPT)
  target     prot opt source               destination
  DOCKER     all  --  0.0.0.0/0           !127.0.0.0/8         ADDRTYPE match dst-

 Chain DOCKER (2 references)
 target     prot opt source               destination

It is in docker@domian. Not inside a container.

EDIT See last comment under surazj' answer

解决方案

I think I met the same problem yet. I either can't start hadoop namenode and datanode by hadoop command "start-all.sh" in docker1.

That is because it launch namenode and datanode through "hadoop-daemons.sh" but it failed. The real problem is "ssh" is not work in docker.

So, you can do either

• (solution 1) :
  Replace all terms "daemons.sh" to "daemon.sh" in start-dfs.sh, than run start-dfs.sh

• (solution 2) : do
  

  $HADOOP_PREFIX/sbin/hadoop-daemon.sh start datanode $HADOOP_PREFIX/sbin/hadoop-daemon.sh start namenode

You can see datanode and namenode are working fine by command "jps"

Regards.

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