Vgrant使用入門

前面我們已經(jīng)學(xué)會(huì)了如何安裝并配置Vagrant，而且也已經(jīng)按照默認(rèn)的方式開啟了，那么這一小節(jié)就給大家介紹一下Vagrant的高級(jí)應(yīng)用。

Vagrant常用命令

前面講了Vagrant的幾個(gè)命令：

• vagrant box add 添加box的操作
• vagrant init 初始化box的操作
• vagrant up 啟動(dòng)虛擬機(jī)的操作
• vagrant ssh 登錄擬機(jī)的操作

Vagrant還包括如下一些操作：

• vagrant box list

  顯示當(dāng)前已經(jīng)添加的box列表

  $ vagrant box list
  base (virtualbox)

• vagrant box remove

  刪除相應(yīng)的box

  $ vagrant box remove base virtualbox
  Removing box 'base' with provider 'virtualbox'...

• vagrant destroy

  停止當(dāng)前正在運(yùn)行的虛擬機(jī)并銷毀所有創(chuàng)建的資源

  $ vagrant destroy
  Are you sure you want to destroy the 'default' VM? [y/N] y
  [default] Destroying VM and associated drives...

• vagrant halt

  關(guān)機(jī)

  $ vagrant halt
  [default] Attempting graceful shutdown of VM...

• vagrant package

  打包命令，可以把當(dāng)前的運(yùn)行的虛擬機(jī)環(huán)境進(jìn)行打包

  $ vagrant package
  [default] Attempting graceful shutdown of VM...
  [default] Clearing any previously set forwarded ports...
  [default] Creating temporary directory for export...
  [default] Exporting VM...
  [default] Compressing package to: /Users/astaxie/vagrant/package.box

• vagrant plugin

  用于安裝卸載插件

• vagrant provision

  通常情況下Box只做最基本的設(shè)置，而不是設(shè)置好所有的環(huán)境，因此Vagrant通常使用Chef或者Puppet來做進(jìn)一步的環(huán)境搭建。那么Chef或者Puppet稱為provisioning，而該命令就是指定開啟相應(yīng)的provisioning。按照Vagrant作者的說法，所謂的provisioning就是"The problem of installing software on a booted system"的意思。除了Chef和Puppet這些主流的配置管理工具之外，我們還可以使用Shell來編寫安裝腳本。

  例如： vagrant provision --provision-with chef

• vagrant reload

  重新啟動(dòng)虛擬機(jī)，主要用于重新載入配置文件

  $ vagrant reload
  [default] Attempting graceful shutdown of VM...
  [default] Setting the name of the VM...
  [default] Clearing any previously set forwarded ports...
  [default] Creating shared folders metadata...
  [default] Clearing any previously set network interfaces...
  [default] Preparing network interfaces based on configuration...
  [default] Forwarding ports...
  [default] -- 22 => 2222 (adapter 1)
  [default] Booting VM...
  [default] Waiting for VM to boot. This can take a few minutes.
  [default] VM booted and ready for use!
  [default] Setting hostname...
  [default] Mounting shared folders...
  [default] -- /vagrant

• vagrant resume

  恢復(fù)前面被掛起的狀態(tài)

  $vagrant resume
  [default] Resuming suspended VM...
  [default] Booting VM...
  [default] Waiting for VM to boot. This can take a few minutes.
  [default] VM booted and ready for use!

• vagrant ssh-config

  輸出用于ssh連接的一些信息

  $vagrant ssh-config
  Host default
    HostName 127.0.0.1
    User vagrant
    Port 2222
    UserKnownHostsFile /dev/null
    StrictHostKeyChecking no
    PasswordAuthentication no
    IdentityFile "/Users/astaxie/.vagrant.d/insecure_private_key"
    IdentitiesOnly yes
    LogLevel FATAL

• vagrant status

  獲取當(dāng)前虛擬機(jī)的狀態(tài)

  $vagrant status
  Current machine states:
  
  default                   running (virtualbox)
  
  The VM is running. To stop this VM, you can run `vagrant halt` to
  shut it down forcefully, or you can run `vagrant suspend` to simply
  suspend the virtual machine. In either case, to restart it again,
  simply run `vagrant up`.

• vagrant suspend

  掛起當(dāng)前的虛擬機(jī)

  $ vagrant suspend
  [default] Saving VM state and suspending execution...

模擬打造多機(jī)器的分布式系統(tǒng)

前面這些單主機(jī)單虛擬機(jī)主要是用來自己做開發(fā)機(jī)，從這部分開始的內(nèi)容主要將向大家介紹如何在單機(jī)上通過虛擬機(jī)來打造分布式造集群系統(tǒng)。這種多機(jī)器模式特別適合以下幾種人：

1. 快速建立產(chǎn)品網(wǎng)絡(luò)的多機(jī)器環(huán)境，例如web服務(wù)器、db服務(wù)器
2. 建立一個(gè)分布式系統(tǒng)，學(xué)習(xí)他們是如何交互的
3. 測(cè)試API和其他組件的通信
4. 容災(zāi)模擬，網(wǎng)絡(luò)斷網(wǎng)、機(jī)器死機(jī)、連接超時(shí)等情況

Vagrant支持單機(jī)模擬多臺(tái)機(jī)器，而且支持一個(gè)配置文件Vagrntfile就可以跑分布式系統(tǒng)。

現(xiàn)在我們來建立多臺(tái)VM跑起來，並且讓他們之間能夠相通信，假設(shè)一臺(tái)是應(yīng)用服務(wù)器、一臺(tái)是DB服務(wù)器，那么這個(gè)結(jié)構(gòu)在Vagrant中非常簡(jiǎn)單，其實(shí)和單臺(tái)的配置差不多，你只需要通過config.vm.define來定義不同的角色就可以了，現(xiàn)在我們打開配置文件進(jìn)行如下設(shè)置：

Vagrant.configure("2") do |config|
  config.vm.define :web do |web|
    web.vm.provider "virtualbox" do |v|
          v.customize ["modifyvm", :id, "--name", "web", "--memory", "512"]
    end
    web.vm.box = "base"
    web.vm.hostname = "web"
    web.vm.network :private_network, ip: "11.11.1.1"
  end

  config.vm.define :db do |db|
    db.vm.provider "virtualbox" do |v|
          v.customize ["modifyvm", :id, "--name", "db", "--memory", "512"]
    end
    db.vm.box = "base"
    db.vm.hostname = "db"
    db.vm.network :private_network, ip: "11.11.1.2"
  end
end

這里的設(shè)置和前面我們單機(jī)設(shè)置配置類似，只是我們使用了:web以及:db分別做了兩個(gè)VM的設(shè)置，并且給每個(gè)VM設(shè)置了不同的hostname和IP，設(shè)置好之后再使用vagrant up將虛擬機(jī)跑起來：

$ vagrant up
Bringing machine 'web' up with 'virtualbox' provider...
Bringing machine 'db' up with 'virtualbox' provider...
[web] Setting the name of the VM...
[web] Clearing any previously set forwarded ports...
[web] Creating shared folders metadata...
[web] Clearing any previously set network interfaces...
[web] Preparing network interfaces based on configuration...
[web] Forwarding ports...
[web] -- 22 => 2222 (adapter 1)
[web] Running any VM customizations...
[web] Booting VM...
[web] Waiting for VM to boot. This can take a few minutes.
[web] VM booted and ready for use!
[web] Setting hostname...
[web] Configuring and enabling network interfaces...
[web] Mounting shared folders...
[web] -- /vagrant
[db] Setting the name of the VM...
[db] Clearing any previously set forwarded ports...
[db] Fixed port collision for 22 => 2222. Now on port 2200.
[db] Creating shared folders metadata...
[db] Clearing any previously set network interfaces...
[db] Preparing network interfaces based on configuration...
[db] Forwarding ports...
[db] -- 22 => 2200 (adapter 1)
[db] Running any VM customizations...
[db] Booting VM...
[db] Waiting for VM to boot. This can take a few minutes.
[db] VM booted and ready for use!
[db] Setting hostname...
[db] Configuring and enabling network interfaces...
[db] Mounting shared folders...
[db] -- /vagrant

看到上面的信息輸出后，我們就可以通過vagrant ssh登錄虛擬機(jī)了，但是這次和上次使用的不一樣了，這次我們需要指定相應(yīng)的角色，用來告訴ssh你期望連接的是哪一臺(tái)：

$ vagrant ssh web
vagrant@web:~$

$ vagrant ssh db
vagrant@db:~$

是不是很酷！現(xiàn)在接下來我們?cè)賮眚?yàn)證一下虛擬機(jī)之間的通信，讓我們先使用ssh登錄web虛擬機(jī)，然后在web虛擬機(jī)上使用ssh登錄db虛擬機(jī)(默認(rèn)密碼是vagrant)：

$ vagrant ssh web
Linux web 2.6.32-38-server #83-Ubuntu SMP Wed Jan 4 11:26:59 UTC 2012 x86_64 GNU/Linux
Ubuntu 10.04.4 LTS

Welcome to the Ubuntu Server!
 * Documentation:  http://www./server/doc
New release 'precise' available.
Run 'do-release-upgrade' to upgrade to it.

Welcome to your Vagrant-built virtual machine.
Last login: Thu Aug  8 18:55:44 2013 from 10.0.2.2
vagrant@web:~$ ssh 11.11.1.2
The authenticity of host '11.11.1.2 (11.11.1.2)' can't be established.
RSA key fingerprint is e7:8f:07:57:69:08:6e:fa:82:bc:1c:f6:53:3f:12:9e.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '11.11.1.2' (RSA) to the list of known hosts.
vagrant@11.11.1.2's password:
Linux db 2.6.32-38-server #83-Ubuntu SMP Wed Jan 4 11:26:59 UTC 2012 x86_64 GNU/Linux
Ubuntu 10.04.4 LTS

Welcome to the Ubuntu Server!
 * Documentation:  http://www./server/doc
New release 'precise' available.
Run 'do-release-upgrade' to upgrade to it.

Welcome to your Vagrant-built virtual machine.
Last login: Thu Aug  8 18:58:50 2013 from 10.0.2.2
vagrant@db:~$

通過上面的信息我們可以看到虛擬機(jī)之間通信是暢通的，所以現(xiàn)在開始你偉大的架構(gòu)設(shè)計(jì)吧，你想設(shè)計(jì)怎么樣的架構(gòu)都可以，唯一限制你的就是你主機(jī)的硬件配置了。