如何使用vagrant在虚拟机安装hadoop集群

原文地址：http://blog.cloudera.com/blog/2013/04/how-to-use-vagrant-to-set-up-a-virtual-hadoop-cluster/

vagrant 是一个非常好用的工具，可以用它来在单台物理机器编程管理多个虚拟机(vms)。其支持原生VirtualBox，并同时提供了对VMware Fusion、Amazon EC2虚拟机集群的插件支持。

vagrant提供了极易使用、基于Ruby的内部DSL，允许用户使用它们的配置参数定义一个或多个虚拟机。另外，对于自动部署，vagrant支持多种机制：可以使用puppet，chef或者用于在vagrant配置文件中定义的所有虚拟机上自动安装软件程序和配置的shell脚本等。

所以，使用vagrant可以在运行着多台vm的系统上定义复杂的虚拟框架，是不是很酷?

vagrant的典型使用案例是以简单并且一致的方式构建工作或者开发环境。在Eligotech（原作者公司）公司里，开发人员正在开发一个产品，目标是让用户简单的使用Apache Hadoop、CDH(Cloudera的开源版本)。开发人员经常是为了测试需要在机器上安装hadoop环境。他们发现vagrant在这方面是一个非常便利的工具。

一个vagrant配置文件的例子，你们可以自行测试。你需要下载并安装vagrant（帮助地址http://docs.vagrantup.com/v2/installation/index.html）和virtualBox。所有东西都安装完毕后即可复制粘贴下面的文本保存为Vagrantfile，并将其放到一个目录下，比如VagrantHadoop.这个配置文件假定你机器内存至少32G，如果不适合可以自行编辑该文件。

# -*- mode: ruby -*-
# vi: set ft=ruby :

$master_script = <<SCRIPT
#!/bin/bash
cat > /etc/hosts <<EOF
127.0.0.1       localhost

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

10.211.55.100   vm-cluster-node1
10.211.55.101   vm-cluster-node2
10.211.55.102   vm-cluster-node3
10.211.55.103   vm-cluster-node4
10.211.55.104   vm-cluster-node5
10.211.55.105   vm-cluster-client
EOF

apt-get install curl -y
REPOCM=${REPOCM:-cm4}
CM_REPO_HOST=${CM_REPO_HOST:-archive.cloudera.com}
CM_MAJOR_VERSION=$(echo $REPOCM | sed -e 's/cm\\([0-9]\\).*/\\1/')
CM_VERSION=$(echo $REPOCM | sed -e 's/cm\\([0-9][0-9]*\\)/\\1/')
OS_CODENAME=$(lsb_release -sc)
OS_DISTID=$(lsb_release -si | tr '[A-Z]' '[a-z]')
if [ $CM_MAJOR_VERSION -ge 4 ]; then
cat > /etc/apt/sources.list.d/cloudera-$REPOCM.list <<EOF
deb [arch=amd64] http://$CM_REPO_HOST/cm$CM_MAJOR_VERSION/$OS_DISTID/$OS_CODENAME/amd64/cm $OS_CODENAME-$REPOCM contrib
deb-src http://$CM_REPO_HOST/cm$CM_MAJOR_VERSION/$OS_DISTID/$OS_CODENAME/amd64/cm $OS_CODENAME-$REPOCM contrib
EOF
curl -s http://$CM_REPO_HOST/cm$CM_MAJOR_VERSION/$OS_DISTID/$OS_CODENAME/amd64/cm/archive.key > key
apt-key add key
rm key
fi
apt-get update
export DEBIAN_FRONTEND=noninteractive
apt-get -q -y --force-yes install oracle-j2sdk1.6 cloudera-manager-server-db cloudera-manager-server cloudera-manager-daemons
service cloudera-scm-server-db initdb
service cloudera-scm-server-db start
service cloudera-scm-server start
SCRIPT

$slave_script = <<SCRIPT
cat > /etc/hosts <<EOF
127.0.0.1       localhost

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

10.211.55.100   vm-cluster-node1
10.211.55.101   vm-cluster-node2
10.211.55.102   vm-cluster-node3
10.211.55.103   vm-cluster-node4
10.211.55.104   vm-cluster-node5
10.211.55.105   vm-cluster-client
EOF
SCRIPT

$client_script = <<SCRIPT
cat > /etc/hosts <<EOF
127.0.0.1       localhost

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

10.211.55.100   vm-cluster-node1
10.211.55.101   vm-cluster-node2
10.211.55.102   vm-cluster-node3
10.211.55.103   vm-cluster-node4
10.211.55.104   vm-cluster-node5
10.211.55.105   vm-cluster-client
EOF
SCRIPT

Vagrant.configure("2") do |config|

config.vm.define :master do |master|
master.vm.box = "precise64"
master.vm.provider "vmware_fusion" do |v|
v.vmx["memsize"]  = "4096"
end
master.vm.provider :virtualbox do |v|
v.name = "vm-cluster-node1"
v.customize ["modifyvm", :id, "--memory", "4096"]
end
master.vm.network :private_network, ip: "10.211.55.100"
master.vm.hostname = "vm-cluster-node1"
master.vm.provision :shell, :inline => $master_script
end

config.vm.define :slave1 do |slave1|
slave1.vm.box = "precise64"
slave1.vm.provider "vmware_fusion" do |v|
v.vmx["memsize"]  = "5120"
end
slave1.vm.provider :virtualbox do |v|
v.name = "vm-cluster-node2"
v.customize ["modifyvm", :id, "--memory", "5120"]
end
slave1.vm.network :private_network, ip: "10.211.55.101"
slave1.vm.hostname = "vm-cluster-node2"
slave1.vm.provision :shell, :inline => $slave_script
end

config.vm.define :slave2 do |slave2|
slave2.vm.box = "precise64"
slave2.vm.provider "vmware_fusion" do |v|
v.vmx["memsize"]  = "5120"
end
slave2.vm.provider :virtualbox do |v|
v.name = "vm-cluster-node3"
v.customize ["modifyvm", :id, "--memory", "5120"]
end
slave2.vm.network :private_network, ip: "10.211.55.102"
slave2.vm.hostname = "vm-cluster-node3"
slave2.vm.provision :shell, :inline => $slave_script
end

config.vm.define :slave3 do |slave3|
slave3.vm.box = "precise64"
slave3.vm.provider "vmware_fusion" do |v|
v.vmx["memsize"]  = "5120"
end
slave3.vm.provider :virtualbox do |v|
v.name = "vm-cluster-node4"
v.customize ["modifyvm", :id, "--memory", "5120"]
end
slave3.vm.network :private_network, ip: "10.211.55.103"
slave3.vm.hostname = "vm-cluster-node4"
slave3.vm.provision :shell, :inline => $slave_script
end

config.vm.define :slave4 do |slave4|
slave4.vm.box = "precise64"
slave4.vm.provider "vmware_fusion" do |v|
v.vmx["memsize"]  = "5120"
end
slave4.vm.provider :virtualbox do |v|
v.name = "vm-cluster-node5"
v.customize ["modifyvm", :id, "--memory", "5120"]
end
slave4.vm.network :private_network, ip: "10.211.55.104"
slave4.vm.hostname = "vm-cluster-node5"
slave4.vm.provision :shell, :inline => $slave_script
end

config.vm.define :client do |client|
client.vm.box = "precise64"
client.vm.provider "vmware_fusion" do |v|
v.vmx["memsize"]  = "4096"
end
client.vm.provider :virtualbox do |v|
v.name = "vm-cluster-client"
v.customize ["modifyvm", :id, "--memory", "4096"]
end
client.vm.network :private_network, ip: "10.211.55.105"
client.vm.hostname = "vm-cluster-client"
client.vm.provision :shell, :inline => $client_script
end

end

配置文件定义了6台vm，并指定了各vm的角色(遵循CDH角色)：

vm-cluster-node1: This is the master; besides running the CM master, it should run the namenode, secondary namenode, and jobtracker.

vm-cluster-node2: This is a slave, it should run a datanode and a tasktracker.

vm-cluster-node3: This is a slave, it should run a datanode and a tasktracker.

vm-cluster-node4: This is a slave, it should run a datanode and a tasktracker.

vm-cluster-node5: This is a slave, it should run a datanode and a tasktracker.

vm-cluster-client: This machine plays the role of gateway for the cluster.

配置文件各配置项意义请点击：http://docs.vagrantup.com/v2/vagrantfile/index.html。特别指出的是依赖于不同的提供商，virtualbox或者vmwarefusion，定义的内存大小是不同的。大家看下，使用不同提供商
定制需要的环境是多么的简单！

上面的vagrant配置文件做了另外一件重要的事情：在master和node1节点自动安装cloudera Manager 。

要创建这个虚拟机集群，只需要到配置文件目录下（比如VagrantHadoop），在shell下运行：

> vagrant up --provider=virtualbox

过一段时间（这个时间随你的机器性能而定），Vagrant运行完毕，意味着所有虚拟机安装配置完毕并且处于运行状态。

到此，你可以通过CM管理UI（http://vm-cluster-node1:7180）配置你的集群。

Have fun！