一：环境准备：
- 首先要有一个Centos7操作系统，可以在虚拟机中安装。
- 在centos7中安装docker，docker的版本为1.8.2
安装步骤如下：
<1>安装制定版本的dockeryum install -y docker-1.8.2-10.el7.centos
<2>安装的时候可能会报错，需要安装这个依赖
rpm -e lvm2-7:2.02.105-14.el7.x86_64
启动docker：
root@gavin:/zhangkun/docker# service docker start
- 关闭防火墙并重启系统：
root@gavin:/zhangkun/docker# systemctl stop firewalld
root@gavin:/zhangkun/docker# systemctl disable firewalld
注意：执行完上面的命令之后需要重启系统
reboot -h(重启系统)
- 关闭selinux
1：setenforce 0(立刻生效，不需要重启操作系统)
2：修改/etc/selinux/config文件中的SELINUX=disabled ，然后重启系统生效
建议两个步骤都执行，这样可以确保系统重启之后selinux也是关闭状态
二：构建一个hadoop的基础镜像，使用dockerfile文件方式进行构建
- 先构建一个具备ssh功能的镜像，方便后期使用
- 创建目录和Dockerfile
root@gavin:/zhangkun/docker# mkdir centos-ssh-root
root@gavin:/zhangkun/docker# cd centos-ssh-root
root@gavin:/zhangkun/docker/centos-ssh-root# vim Dockerfile
Dockerfile内容如下：
# 选择一个已有的os镜像作为基础
FROM centos
# 镜像的作者
MAINTAINER gavin
# 安装openssh-server和sudo软件包，并且将sshd的UsePAM参数设置成no
RUN yum install -y openssh-server sudo
RUN sed -i 's/UsePAM yes/UsePAM no/g' /etc/ssh/sshd_config
#安装openssh-clients
RUN yum install -y openssh-clients
# 添加测试用户root，密码wjht2014，并且将此用户添加到sudoers里
RUN echo "root:wjht2014" | chpasswd
RUN echo "root ALL=(ALL) ALL" >> /etc/sudoers
# 下面这两句比较特殊，在centos6上必须要有，否则创建出来的容器sshd不能登录
RUN ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key
RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
# 启动sshd服务并且暴露22端口
RUN mkdir /var/run/sshd
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]
- 执行docker build 命令
root@gavin:/zhangkun/docker/centos-ssh-root# docker build -t gavin/centos-ssh-root:1.0 .
结果如下：
Sending build context to Docker daemon 2.56 kB
Step 1 : FROM centos
---> a8493f5f50ff
Step 2 : MAINTAINER gavin
---> Running in 61eb94a2295e
---> 699e5edbbe6c
Removing intermediate container 61eb94a2295e
Step 3 : RUN yum install -y openssh-server sudo
---> Running in c0b03b62bc6a
Loaded plugins: fastestmirror, ovl
Determining fastest mirrors
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Resolving Dependencies
--> Running transaction check
---> Package openssh-server.x86_64 0:7.4p1-13.el7_4 will be installed
--> Processing Dependency: openssh = 7.4p1-13.el7_4 for package: openssh-server-7.4p1-13.el7_4.x86_64
--> Processing Dependency: fipscheck-lib(x86-64) >= 1.3.0 for package: openssh-server-7.4p1-13.el7_4.x86_64
--> Processing Dependency: libcrypto.so.10(OPENSSL_1.0.2)(64bit) for package: openssh-server-7.4p1-13.el7_4.x86_64
--> Processing Dependency: libwrap.so.0()(64bit) for package: openssh-server-7.4p1-13.el7_4.x86_64
--> Processing Dependency: libfipscheck.so.1()(64bit) for package: openssh-server-7.4p1-13.el7_4.x86_64
---> Package sudo.x86_64 0:1.8.19p2-11.el7_4 will be installed
--> Running transaction check
---> Package fipscheck-lib.x86_64 0:1.4.1-6.el7 will be installed
--> Processing Dependency: /usr/bin/fipscheck for package: fipscheck-lib-1.4.1-6.el7.x86_64
---> Package openssh.x86_64 0:7.4p1-13.el7_4 will be installed
---> Package openssl-libs.x86_64 1:1.0.1e-60.el7_3.1 will be updated
---> Package openssl-libs.x86_64 1:1.0.2k-8.el7 will be an update
---> Package tcp_wrappers-libs.x86_64 0:7.6-77.el7 will be installed
--> Running transaction check
---> Package fipscheck.x86_64 0:1.4.1-6.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
openssh-server x86_64 7.4p1-13.el7_4 updates 458 k
sudo x86_64 1.8.19p2-11.el7_4 updates 1.1 M
Installing for dependencies:
fipscheck x86_64 1.4.1-6.el7 base 21 k
fipscheck-lib x86_64 1.4.1-6.el7 base 11 k
openssh x86_64 7.4p1-13.el7_4 updates 509 k
tcp_wrappers-libs x86_64 7.6-77.el7 base 66 k
Updating for dependencies:
openssl-libs x86_64 1:1.0.2k-8.el7 base 1.2 M
Transaction Summary
================================================================================
Install 2 Packages (+4 Dependent packages)
Upgrade ( 1 Dependent package)
Total download size: 3.3 M
Downloading packages:
Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
warning: /var/cache/yum/x86_64/7/base/packages/fipscheck-lib-1.4.1-6.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Public key for fipscheck-lib-1.4.1-6.el7.x86_64.rpm is not installed
Public key for openssh-server-7.4p1-13.el7_4.x86_64.rpm is not installed
--------------------------------------------------------------------------------
Total 1.6 MB/s | 3.3 MB 00:02
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Importing GPG key 0xF4A80EB5:
Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>"
Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5
Package : centos-release-7-3.1611.el7.centos.x86_64 (@CentOS)
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Updating : 1:openssl-libs-1.0.2k-8.el7.x86_64 1/8
Installing : fipscheck-1.4.1-6.el7.x86_64 2/8
Installing : fipscheck-lib-1.4.1-6.el7.x86_64 3/8
Installing : openssh-7.4p1-13.el7_4.x86_64 4/8
Installing : tcp_wrappers-libs-7.6-77.el7.x86_64 5/8
Installing : openssh-server-7.4p1-13.el7_4.x86_64 6/8
Installing : sudo-1.8.19p2-11.el7_4.x86_64 7/8
Cleanup : 1:openssl-libs-1.0.1e-60.el7_3.1.x86_64 8/8
Verifying : fipscheck-lib-1.4.1-6.el7.x86_64 1/8
Verifying : tcp_wrappers-libs-7.6-77.el7.x86_64 2/8
Verifying : fipscheck-1.4.1-6.el7.x86_64 3/8
Verifying : openssh-7.4p1-13.el7_4.x86_64 4/8
Verifying : openssh-server-7.4p1-13.el7_4.x86_64 5/8
Verifying : 1:openssl-libs-1.0.2k-8.el7.x86_64 6/8
Verifying : sudo-1.8.19p2-11.el7_4.x86_64 7/8
Verifying : 1:openssl-libs-1.0.1e-60.el7_3.1.x86_64 8/8
Installed:
openssh-server.x86_64 0:7.4p1-13.el7_4 sudo.x86_64 0:1.8.19p2-11.el7_4
Dependency Installed:
fipscheck.x86_64 0:1.4.1-6.el7 fipscheck-lib.x86_64 0:1.4.1-6.el7
openssh.x86_64 0:7.4p1-13.el7_4 tcp_wrappers-libs.x86_64 0:7.6-77.el7
Dependency Updated:
openssl-libs.x86_64 1:1.0.2k-8.el7
Complete!
---> c996aae83415
Removing intermediate container c0b03b62bc6a
Step 4 : RUN sed -i 's/UsePAM yes/UsePAM no/g' /etc/ssh/sshd_config
---> Running in 1dfac6d4e6c4
---> 2659da5a35a8
Removing intermediate container 1dfac6d4e6c4
Step 5 : RUN yum install -y openssh-clients
---> Running in aad53bc05a7b
Loaded plugins: fastestmirror, ovl
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Resolving Dependencies
--> Running transaction check
---> Package openssh-clients.x86_64 0:7.4p1-13.el7_4 will be installed
--> Processing Dependency: libedit.so.0()(64bit) for package: openssh-clients-7.4p1-13.el7_4.x86_64
--> Running transaction check
---> Package libedit.x86_64 0:3.0-12.20121213cvs.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
openssh-clients x86_64 7.4p1-13.el7_4 updates 654 k
Installing for dependencies:
libedit x86_64 3.0-12.20121213cvs.el7 base 92 k
Transaction Summary
================================================================================
Install 1 Package (+1 Dependent package)
Total download size: 746 k
Installed size: 2.8 M
Downloading packages:
--------------------------------------------------------------------------------
Total 2.0 MB/s | 746 kB 00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : libedit-3.0-12.20121213cvs.el7.x86_64 1/2
Installing : openssh-clients-7.4p1-13.el7_4.x86_64 2/2
Verifying : libedit-3.0-12.20121213cvs.el7.x86_64 1/2
Verifying : openssh-clients-7.4p1-13.el7_4.x86_64 2/2
Installed:
openssh-clients.x86_64 0:7.4p1-13.el7_4
Dependency Installed:
libedit.x86_64 0:3.0-12.20121213cvs.el7
Complete!
---> 1fd66ba4a305
Removing intermediate container aad53bc05a7b
Step 6 : RUN echo "root:wjht2014" | chpasswd
---> Running in f1386389be9d
---> 11efd1c6468e
Removing intermediate container f1386389be9d
Step 7 : RUN echo "root ALL=(ALL) ALL" >> /etc/sudoers
---> Running in f2fa0bf8f0ff
---> 66f1dbf23fcb
Removing intermediate container f2fa0bf8f0ff
Step 8 : RUN ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key
---> Running in f200ca8c6f74
Enter passphrase (empty for no passphrase): Enter same passphrase again: Generating public/private dsa key pair.
Your identification has been saved in /etc/ssh/ssh_host_dsa_key.
Your public key has been saved in /etc/ssh/ssh_host_dsa_key.pub.
The key fingerprint is:
SHA256:JXnM8q/diLBuHm4imfhwLXuI1LijSKSkPfAXWwf5V+E root@f85c553c1496
The key's randomart image is:
+---[DSA 1024]----+
| . |
| . + . . |
| o + = E |
| o * . |
|.o o. . S o |
|=+o .= . . . |
|oo=+=+. o . |
|o ===oo.o+ + o |
|o. ooo *= o o . |
+----[SHA256]-----+
---> e2e0212a4a62
Removing intermediate container f200ca8c6f74
Step 9 : RUN ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
---> Running in 13e6e8697fae
Enter passphrase (empty for no passphrase): Enter same passphrase again: Generating public/private rsa key pair.
Your identification has been saved in /etc/ssh/ssh_host_rsa_key.
Your public key has been saved in /etc/ssh/ssh_host_rsa_key.pub.
The key fingerprint is:
SHA256:CP3IFXtxF21OCa3DQ8pqXCT/P0t4laSMnFhlylIBbMY root@f85c553c1496
The key's randomart image is:
+---[RSA 2048]----+
| +.ooo+=o.|
| . Eo++o o+|
| . . =.*++ .= |
| o = .==+=o o|
| + S.o+.oo..|
| + .. .|
| . ..o |
| oo |
| .o|
+----[SHA256]-----+
---> 62506c433eda
Removing intermediate container 13e6e8697fae
Step 10 : RUN mkdir /var/run/sshd
---> Running in 3db5261c4757
---> cec11f2ba2d8
Removing intermediate container 3db5261c4757
Step 11 : EXPOSE 22
---> Running in bd793050ef89
---> d8afedd8edc3
Removing intermediate container bd793050ef89
Step 12 : CMD /usr/sbin/sshd -D
---> Running in c44d33719c82
---> 7fe06a0a3cf2
Removing intermediate container c44d33719c82
Successfully built 7fe06a0a3cf2
看到Successfully built 即构建成功
- 基于这个镜像再构建一个带有jdk的镜像
- 创建目录和Dockerfile
root@gavin:/zhangkun/docker# mkdir centos-ssh-root-jdk
root@gavin:/zhangkun/docker# cd centos-ssh-root-jdk
root@gavin:/zhangkun/docker/centos-ssh-root-jdk#vim Dockerfile
Dockerfile内容如下：
FROM gavin/centos-ssh-root:v1.0
ADD jdk-8u161-linux-x64.tar.gz /usr/local/
RUN mv /usr/local/jdk1.8.0_161 /usr/local/jdk1.8
ENV JAVA_HOME /usr/local/jdk1.8
ENV PATH $JAVA_HOME/bin:$PATH
下载jdk-8u161-linux-x64.tar.gz
链接: https://pan.baidu.com/s/1kWHkmIN 密码: dt56将下载的jdk放到centos-ssh-root-jdk目录下
root@gavin:/zhangkun/docker/centos-ssh-root-jdk#sudo cp /home/gavin/下载/jdk-8u161-linux-x64.tar.gz ./
- 构建镜像：
root@gavin:/zhangkun/docker/centos-ssh-root-jdk# docker build -t gavin/centos-ssh-root-jdk:v1.0 .
结果如下：
Sending build context to Docker daemon 189.8 MB
Step 1 : FROM gavin/centos-ssh-root:v1.0
---> 7fe06a0a3cf2
Step 2 : ADD jdk-8u161-linux-x64.tar.gz /usr/local/
---> dbd69ff9138e
Removing intermediate container 349dc08eeb98
Step 3 : RUN mv /usr/local/jdk1.8.0_161 /usr/local/jdk1.8
---> Running in 749f2cd8d1eb
---> 1b3da34e1112
Removing intermediate container 749f2cd8d1eb
Step 4 : ENV JAVA_HOME /usr/local/jdk1.8
---> Running in 3ca9941d839e
---> 570fe947048e
Removing intermediate container 3ca9941d839e
Step 5 : ENV PATH $JAVA_HOME/bin:$PATH
---> Running in dac0d7608397
---> bfa7c2cb375e
Removing intermediate container dac0d7608397
Successfully built bfa7c2cb375e
- 基于这个jdk镜像再构建一个带有hadoop的镜像
- 创建目录和Dockerfile
root@gavin:/zhangkun/docker# mkdir centos-ssh-root-jdk-hadoop
root@gavin:/zhangkun/docker# cd centos-ssh-root-jdk-hadoop/
root@gavin:/zhangkun/docker/centos-ssh-root-jdk-hadoop# vim Dockerfile
Dockerfile内容如下：
FROM gavin/centos-ssh-root-jdk:v1.0
ADD hadoop-2.4.1.tar.gz /usr/local
RUN mv /usr/local/hadoop-2.4.1 /usr/local/hadoop
ENV HADOOP_HOME /usr/local/hadoop
ENV PATH $HADOOP_HOME/bin:$PATH
下载hadoop-2.4.1.tar.gz
链接: https://pan.baidu.com/s/1o9fkxRG 密码: t8hb构建镜像
root@gavin:/zhangkun/docker/centos-ssh-root-jdk-hadoop# docker build -t gavin/gavin/centos-ssh-root-jdk-hadoop:v1.0 .
结果如下：
Sending build context to Docker daemon 138.7 MB
Step 1 : FROM gavin/centos-ssh-root-jdk:v1.0
---> bfa7c2cb375e
Step 2 : ADD hadoop-2.4.1.tar.gz /usr/local
---> d7615a5d6599
Removing intermediate container 85de43d7f162
Step 3 : RUN mv /usr/local/hadoop-2.4.1 /usr/local/hadoop
---> Running in 889d669375bd
---> ef463ffd5e70
Removing intermediate container 889d669375bd
Step 4 : ENV HADOOP_HOME /usr/local/hadoop
---> Running in 34aeb57db70d
---> f24fdd8f7e2d
Removing intermediate container 34aeb57db70d
Step 5 : ENV PATH $HADOOP_HOME/bin:$PATH
---> Running in 5bee04e663b4
---> 556d46804532
Removing intermediate container 5bee04e663b4
Successfully built 556d46804532
构建的三个镜像如下：
root@gavin:/zhangkun/docker/centos-ssh-root-jdk-hadoop# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
gavin/gavin/centos-ssh-root-jdk-hadoop v1.0 556d46804532 3 hours ago 1.631 GB
gavin/centos-ssh-root-jdk v1.0 bfa7c2cb375e 4 hours ago 1.162 GB
gavin/centos-ssh-root v1.0 7fe06a0a3cf2 4 hours ago 393 MB
三：搭建hadoop分布式集群
- 集群规划
准备搭建一个具有三个节点的集群，一主两从
主节点：hadoop0 ip：192.168.10.3(5022)
从节点1：hadoop1 ip：192.168.10.4 (3022)
从节点2：hadoop2 ip：192.168.10.5(4022)
但是由于docker容器重新启动之后ip会发生变化，所以需要我们给docker设置固定ip。使用pipework给 docker容器设置固定ip
- 启动三个容器，分别作为hadoop0 hadoop1 hadoop2
在宿主机上执行下面命令，给容器设置主机名和容器的名称，并且在hadoop0中对外开放端口50070 和8088
docker run --name hadoop0 --hostname hadoop0 -d -P -p 50070:50070 -p 8088:8088 crxy/centos-ssh-root-jdk-hadoop
docker run --name hadoop1 --hostname hadoop1 -d -P crxy/centos-ssh-root-jdk-hadoop
docker run --name hadoop2 --hostname hadoop2 -d -P crxy/centos-ssh-root-jdk-hadoop
- 给这三台容器设置固定IP
- 下载PipeWoke
root@gavin:/zhangkun/docker#git clone https://github.com/jpetazzo/pipework
root@gavin:/zhangkun/docker#cp pipework/pipework /usr/local/bin/
- 安装网桥工具
root@gavin:/zhangkun/docker#yum -y install bridge-utils
- 创建网络
root@gavin:/zhangkun/docker#brctl addbr br0
root@gavin:/zhangkun/docker#ip link set dev br0 up
root@gavin:/zhangkun/docker#ip addr add 192.168.10.1/24 dev br0
- 给容器设置固定ip
root@gavin:/zhangkun/docker#pipework br0 hadoop0 192.168.10.3/24
root@gavin:/zhangkun/docker#pipework br0 hadoop1 192.168.10.4/24
root@gavin:/zhangkun/docker#pipework br0 hadoop2 192.168.10.5/24
- 配置hadoop集群
- 先连接到hadoop0上，
root@gavin:/zhangkun/docker#docker exec -it hadoop0 /bin/bash
下面的步骤就是hadoop集群的配置过程
- 设置主机名与ip的映射，修改三台容器：vi /etc/hosts
添加下面配置
192.168.2.10 hadoop0
192.168.2.11 hadoop1
192.168.2.12 hadoop2
- 设置ssh免密码登录
在hadoop0上执行下面操作
cd ~
mkdir .ssh
cd .ssh
ssh-keygen -t rsa(一直按回车即可)
ssh-copy-id -i localhost
ssh-copy-id -i hadoop0
ssh-copy-id -i hadoop1
ssh-copy-id -i hadoop2
在hadoop1上执行下面操作
cd ~
cd .ssh
ssh-keygen -t rsa(一直按回车即可)
ssh-copy-id -i localhost
ssh-copy-id -i hadoop1
在hadoop2上执行下面操作
cd ~
cd .ssh
ssh-keygen -t rsa(一直按回车即可)
ssh-copy-id -i localhost
ssh-copy-id -i hadoop2
- 在hadoop0上修改hadoop的配置文件
进入到/usr/local/hadoop/etc/hadoop目录
修改目录下的配置文件core-site.xml、hdfs-site.xml、yarn-site.xml、mapred-site.xml
(1) hadoop-env.sh
export JAVA_HOME=/usr/local/jdk1.8
(2)core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://hadoop0:9000</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/usr/local/hadoop/tmp</value>
</property>
<property>
<name>fs.trash.interval</name>
<value>1440</value>
</property>
</configuration>
(3)hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
<property>
<name>dfs.permissions</name>
<value>false</value>
</property>
</configuration>
(4)yarn-site.xml
<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.log-aggregation-enable</name>
<value>true</value>
</property>
</configuration>
(5)修改文件名：mv mapred-site.xml.template mapred-site.xml
vi mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
</configuration>
(6)格式化
进入到/usr/local/hadoop目录下
- 执行格式化命令
bin/hdfs namenode -format
注意：在执行的时候会报错，是因为缺少which命令，安装即可
执行下面命令安装
yum install -y which
看到下面命令说明格式化成功。
这里写图片描述
格式化操作不能重复执行。如果一定要重复格式化，带参数-force即可。
(7)启动伪分布hadoop
命令：sbin/start-all.sh
第一次启动的过程中需要输入yes确认一下。
这里写图片描述
使用jps，检查进程是否正常启动？能看到下面几个进程表示伪分布启动成功
[root@hadoop0 hadoop]# jps
818 ResourceManager
1239 Jps
522 DataNode
411 NameNode
669 SecondaryNameNode
909 NodeManager
(8)停止伪分布hadoop
命令：sbin/stop-all.sh
(9)指定nodemanager的地址，修改文件yarn-site.xml
<property>
<description>The hostname of the RM.</description>
<name>yarn.resourcemanager.hostname</name>
<value>hadoop0</value>
</property>
(10)修改hadoop0中hadoop的一个配置文件etc/hadoop/slaves
删除原来的所有内容，修改为如下
hadoop1
hadoop2
(11)在hadoop0中执行命令
scp -rq /usr/local/hadoop hadoop1:/usr/local
scp -rq /usr/local/hadoop hadoop2:/usr/local
(12)启动hadoop分布式集群服务
执行sbin/start-all.sh
注意：在执行的时候会报错，是因为两个从节点缺少which命令，安装即可
分别在两个从节点执行下面命令安装
yum install -y which
1
再启动集群(如果集群已启动，需要先停止)
sbin/start-all.sh
(13)验证集群是否正常
首先查看进程：
Hadoop0上需要有这几个进程
[root@hadoop0 hadoop]# jps
4643 Jps
4073 NameNode
4216 SecondaryNameNode
4381 ResourceManager
Hadoop1上需要有这几个进程
[root@hadoop1 hadoop]# jps
715 NodeManager
849 Jps
645 DataNode
Hadoop2上需要有这几个进程
[root@hadoop2 hadoop]# jps
456 NodeManager
589 Jps
388 DataNode
使用程序验证集群服务
创建一个本地文件
vi a.txt
hello you
hello me
上传a.txt到hdfs上
hdfs dfs -put a.txt /
执行wordcount程序
cd /usr/local/hadoop/share/hadoop/mapreduce
hadoop jar hadoop-mapreduce-examples-2.4.1.jar wordcount /a.txt /out
查看程序执行结果
这里写图片描述
这样就说明集群正常了。
在这可以直接通过宿主机访问容器中hadoop集群的服务
宿主机的ip为：192.168.1.27
http://192.168.1.27:50070/
http://192.168.1.27:8088/
四：集群节点重启
停止三个容器，在宿主机上执行下面命令
docker stop hadoop0
docker stop hadoop1
docker stop hadoop2
容器停止之后，之前设置的固定ip也会消失，重新再使用这几个容器的时候还需要重新设置固定ip
先把之前停止的三个容器起来
docker start hadoop0
docker start hadoop1
docker start hadoop2
在宿主机上执行下面命令重新给容器设置固定ip
pipework br0 hadoop0 192.168.2.10/24
pipework br0 hadoop1 192.168.2.11/24
pipework br0 hadoop2 192.168.2.12/24
还需要重新在容器中配置主机名和ip的映射关系，每次都手工写比较麻烦
写一个脚本，runhosts.sh
#!/bin/bash
echo 192.168.2.10 hadoop0 >> /etc/hosts
echo 192.168.2.11 hadoop1 >> /etc/hosts
echo 192.168.2.12 hadoop2 >> /etc/hosts
添加执行权限，chmod +x runhosts.sh
把这个脚本拷贝到所有节点，并且分别执行这个脚本
scp runhosts.sh hadoop1:~
scp runhosts.sh hadoop2:~
执行脚本的命令 ./runhosts.sh
查看/etc/hosts文件中是否添加成功
这里写图片描述
注意：有一些docker版本中不会在hosts文件中自动生成下面这些映射，所以我们才在这里手工给容器设置固定ip，并设置主机名和ip的映射关系。
172.17.0.25 hadoop0
172.17.0.25 hadoop0.bridge
172.17.0.26 hadoop1
172.17.0.26 hadoop1.bridge
172.17.0.27 hadoop2
172.17.0.27 hadoop2.bridge
启动hadoop集群
sbin/start-all.sh
