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27 Aug 2019
Chef

What is Chef

Chef 是一个可以提供代码即基础设施的的自动化工具。C/S架构：

nodes可以动态更新server端的配置，pull configuration，不需要在server端执行push configuration到node的命令，所有的node都可以自动更新server端的配置。像Chef 和 Puppet都是pull configuration。

与之相对的 push configuration，ansible。

Chef 有三大组件:

  • Workstation

    • 用于写 Cookbooks 和 Recipes， 这些会被push到 central Chef Server
    • 管理 central Chef Server 的节点。

    Workstations 有两大组件:

    • Knife utility
    • A local Chef repository

  • Server

    类似于一个配置数据的hub. Chef Server 存储 Cookbooks, 应用到Nodes的 policies, 和描述注册节点的元数据（被Chef-Client管理）.

    Nodes 通过 Chef-Client 去向 Chef Server 获取配置详情，比如 Recipes, Templates, and file distributions.

    每个节点都安装有 Chef Client , 它会从 Chef Server pull down 配置文件.

  • Nodes

    主要的组件就是Chef Client, 它主要有以下功能：

    • 负责与 central Chef Server交互.
    • 管理Node到 central Chef Server 的初始注册.
    • 拉取 Cookbooks, 并 apply 到 Node 进行配置.
    • 周期性轮训 central Chef Server 获取新的配置

Install Chef

Following are the steps to install Chef:

  1. Install Chef DK (Development Kit) on Chef Workstation

     #wget https://packages.chef.io/stable/el/6/chefdk-1.0.3-1.el6.x86_64.rpm
 #rpm -ivh chefdk-1.0.3-1.el6.x86_64.rpm

    Create a Recipe in the Workstation, you will see the file with this content:

     #mkdir chef-repo
 #cd chef-repo
 #vim edureka.rb , add : 
	
 file '/etc/motd' do
 content 'Welcome to Chef' 
 end
	
 #chef-apply edureka.rb

    Modifying Recipe file to install httpd package, you can go to localhost through Chrome:

     #vim edureka.rb
 package 'httpd'
 service 'httpd' do
 action [:enable, :start]
 end
 file '/var/www/html/index.html' do
 content 'Welcome to Apache in Chef'
 end
 #chef-apply edureka.rb

  2. Create a Recipe or a Cookbook in Workstation

     #cd chef-repo
 #mkdir cookbooks
 #cd cookbooks
 #chef generate cookbook httpd_deploy
 #cd httpd_deploy
 #tree

    Create a Template file:

    #chef generate template httpd_deploy index.html

     #cd /root/chef-repo/cookbook/httpd_deploy/templates
 #vim index.html.erb
 Welcome to Chef Apache Deployment

    Create a Recipe with this template:

     #cd /root/chef-repo/cookbooks/httpd_deploy/recipes
 #vim default.rb
 package 'httpd'
 service 'httpd' do
 action [:enable, :start]
 end
 template '/var/www/html/index.html' do
 source 'index.html.erb'
 end
 #cd /root/chef-repo
 #chef-client --local-mode --runlist 'recipe[httpd_deploy]'

  3. Setup a Chef Server

    hosted version of Chef Server on the cloud

     download starter kit 
	
 #unzip chef-starter.zip
	
 #mv starter /root/chef-repo/cookbooks

  4. download a Cookbook from Chef Supermarket in Workstation

     #cd chef-repo
 #knife cookbook site download learn_chef_httpd
 #tar -xvf learn_chef_httpd-0.2.0.tar.gz
 #cd /root/chef-repo/learn_chef_httpd/recipes

  5. Upload a Cookbook on the Chef Server

     #mv /root/chef-repo/learn_chef_httpd /root/chef-repo/cookbooks
 #cd /root/chef-repo/cookbooks
 #knife cookbook upload learn_chef_httpd

  6. Connect A Node To The Chef Server

     // 192.168.56.102是一个node的IP
 #knife bootstrap 192.168.56.102 --ssh-user root --ssh-password edureka --node-name chefNode 
 #Knife node list

  7. Deploy the Cookbook from the Server to the Node

     manage its Run list from the Chef Server
 node# chef-client

Chef Solo

当你只需要设置一台server的时候，使用chef server 和 chef client就太重了，这个时候我们就可以使用chef-solo。

local machine上面有这些文件：

deploy.sh     <--- run "./deploy.sh" on your laptop to deploy
install.sh    <--- this is run on the server to bootstrap and call chef-solo
solo.json     <--- chef configuration
solo.rb       <--- chef configuration
cookbooks/op/recipes/default.rb   <--- the most important file -- your
                                       server recipe goes here

deploy.sh

#!/bin/bash

# Usage: ./deploy.sh [host]

host="${1:-ubuntu@opinionatedprogrammer.com}"

# The host key might change when we instantiate a new VM, so
# we remove (-R) the old host key from known_hosts
ssh-keygen -R "${host#*@}" 2> /dev/null

tar cj . | ssh -o 'StrictHostKeyChecking no' "$host" '
sudo rm -rf ~/chef &&
mkdir ~/chef &&
cd ~/chef &&
tar xj &&
sudo bash install.sh'

Til next time,
at 09:42

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