Ansible（三）编写ansible的playbook文件（实现端口更改、远程主机信息采集、负载均衡）

2024-01-11 10:57:40

1.playbook简介

playbooks是一个不同于使用Ansible命令行执行方式的模式，其功能更强大灵活。简单来说，playbook是一个非常简单的配置管理和多主机部署系统，不同于任何已经存在的模式，可作为一个适合部署复杂应用程序的基础。Playbook可以定制配置，可以按照指定的操作步骤有序执行，支持同步和异步方式。值得注意的是playbook是通过YAML格式来进行描述定义的。
核心元素：

Tasks：任务，由模板定义的操作列表
Variables：变量
Templates：模板，即使用模板语法的文件
Handlers：处理器，当某条件满足时，触发执行的操作
Roles：角色

在playbook中的每一个play都可以选择在哪些服务器和以什么用户完成，hosts一行可以是一个主机组、主机、多个主机，中间以冒号分隔，可使用通配模式。其中remote_user表示执行的用户账号。

hosts: abc #指定主机组，可以是一个或多个组
remote_user: root #指定远程主机执行的用户名

指定远程主机sudo切换用

#vim ping.yml
—
- hosts: abc
remote_user: root
become: yes #2.6版本以后的参数，之前是sudo，意思为切换用户运行
become_user: mysql #指定sudo用户为mysql
执行playbook
# ansible-playbook ping.yml -K

Tasks list 和action介绍

1：Play的主体部分是task列表，task列表中的各任务按次序逐个在hosts中指定的主机上执行，即在所有主机上完成第一个任务后再开始第二个任务。
在运行playbook时（从上到下执行），如果一个host执行task失败，整个tasks都会回滚，请修正playbook 中的错误，然后重新执行即可。
Task的目的是使用指定的参数执行模块，而在模块参数中可以使用变量，模块执行时幂等的，这意味着多次执行是安全的，因为其结果一致。
2：每一个task必须有一个名称name，这样在运行playbook时，从其输出的任务执行信息中可以很好的辨别出是属于哪一个task的。如果没有定义name，‘action’的值将会用作输出信息中标记特定的task。
3：定义一个task，常见的格式:”module: options” 例如：yum: name=httpd
4：ansible的自带模块中，command模块和shell模块无需使用key=value格式

常用命令
ansible-playbook [yaml文件名、也可以yml结尾]
例如：ansible-playbook a.yml
参数：

-k(–ask-pass) 用来交互输入ssh密码
-K(-ask-become-pass) 用来交互输入sudo密码
-u 指定用户

#ansible-playbook a.yml --syntax-check #检查yaml文件的语法是否正确
#ansible-playbook a.yml --list-task #检查tasks任务
#ansible-playbook a.yml --list-hosts #检查生效的主机
#ansible-playbook a.yml --start-at-task=‘Copy Nginx.conf’ #指定从某个task开始运行

2、编写playbook实现自动安装服务

1、yml文件语法的要求是python语法，非常的严格，为了方便我们的使用，我们先编写一个特定的vim，一个tab等于两个空格

[devopes@server1 ansible]$ vim .vimrc
[devopes@server1 ansible]$ cat .vimrc
autocmd FileType yaml setlocal ai ts=2 sw=2 et

2、开始编写yml文件

[devopes@server4 ansible]$ pwd
/home/devopes
[devopes@server4 ansible]$ ls
ansible
[devopes@server4 ansible]$ cd ansible/
[devopes@server4 ansible]$ ls
ansible.cfg inventory
[devopes@server4 ansible]$ vim playbook.yml
[devopes@server4 ansible]$ cat playbook.yml 
---
- hosts: prod
  tasks:
    - name: install httpd
      yum:
        name: httpd
        state: present
    - name: start httpd
      service:
        name: httpd
        state: started

3、检测语法

[devopes@server4 ansible]$ ansible-playbook playbook.yml --syntax-check     #检查yaml文件的语法是否正确
playbook: playbook.yml
[devopes@server4 ansible]$ ansible-playbook playbook.yml --list-task   #检查tasks任务
playbook: playbook.yml
  play #1 (prod): prod	TAGS: []
    tasks:
      install httpd	TAGS: []
      start httpd	TAGS: []
[devopes@server4 ansible]$ ansible-playbook playbook.yml --list-hosts   #检查生效的主机
playbook: playbook.yml

  play #4 (prod): prod	TAGS: []
    pattern: [u'prod']
    hosts (1):
      172.25.35.6
[devopes@server1 ansible]$ ansible-playbook playbook.yml

4、在server6上查看
方法一：

方法二：

3、编写playbook实现修改配置文件，并且加入触发器

1、编辑playbook.yml文件

[devopes@server1 ansible]$ vim playbook.yml
[devopes@server1 ansible]$ cat playbook.yml 
---
- hosts: prod
  tasks:
    - name: install httpd
      yum:
        name: httpd
        state: present

    - name: configure httpd
      copy:
        src: files/httpd.conf
        dest: /etc/httpd/conf/httpd.conf
        owner: root
        group: root
        mode: 644
      notify: restart httpd

    - name: start  httpd
      service:
        name: httpd
        state: started
  
  handlers:
    - name: restart httpd
      service:
        name: httpd
        state: restarted

2、创建目录并拷贝.conf文件

[devopes@server1 ansible]$ ls
ansibe.cfg   inventory   playbook.yml    
[devopes@server1 ansible]$ mkdir files
[devopes@server1 ansible]$ ls
[devopes@server1 ansible]$ cd files/
[devopes@server1 files]$  ls
[devopes@server1 files]$ scp server6:/etc/httpd/conf/httpd.conf .
[devopes@server1 files]$ ls
[devopes@server1 files]$ cd ..
[devopes@server1 ansible]$ ls

3、执行.yml文件

[devopes@server1 ansible]$ ansible-playbook playbook.yml

4、查看端口，发现80端口生效

[root@server6 ~]# netstat -antlp

5、为了再次验证，我们将httpd中的80端口更改为8080

[devopes@server4 ansible]$ ls
ansible.cfg  files  inventory  playbook.retry  playbook.yml
[devopes@server4 ansible]$ cd files
[devopes@server4 files]$ ls
httpd.conf
[devopes@server4 files]$ vim httpd.conf   ###改变端口为8080
[devopes@server4 files]$ cd ..
[devopes@server4 ansible]$ ansible-playbook playbook.yml

6、执行完毕再次去查看端口发现端口改变成功（已经为8080）

[root@server6 ~]# netstat -antlp   ##此时端口为8080

为了后面实验的方便，更改完之后我们在将端口改回去。

4 、通过ansible给server3加入发布页面并实现给本地访问测试server6上服务

1、编辑.yml文件，在其中加入发布页面的模块

[devopes@server4 ansible]$ vim playbook.yml 
[devopes@server4 ansible]$ cat playbook.yml 
---
- hosts: webserver
  tasks:
    - name: install httpd
      yum:
        name: httpd
        state: present

    - name: copy index.html
      copy:
        src: files/index.html
        dest: /var/www/html/index.html

    - name: configure httpd
      copy:
        src: files/httpd.conf
        dest: /etc/httpd/conf/httpd.conf
        owner: root
        group: root
        mode: 644
      notify: restart httpd

    - name: start  httpd and firewalld
      service:
        name: "{{item}}"
        state: started
      loop:
        - httpd
        - firewalld

    - name: configure firewalld
      firewalld:
        service: http
        permanent: yes 
        immediate: yes
        state: enabled
 
  handlers:
    - name: restart httpd
      service:
        name: httpd
        state: restarted

- hosts: localhost
  become: no
  tasks:
    - name: test httpd
      uri:
        url: http://172.25.35.6
        status_code: 200

2、此时我们去执行.yml文件，发现会报错，这是因为没有发布页面，下面我们需要给她添加

[devopes@server4 ansible]$ ansible-playbook playbook.yml   ##报错
[devopes@server4 ansible]$ ls
ansible.cfg  files  inventory  playbook.retry  playbook.yml
[devopes@server4 ansible]$ cd files
[devopes@server4 files]$ echo www.westos.org > index.html
[devopes@server4 files]$ cd -
/home/devopes/ansible

3、添加之后再次去执行发现，还是报错（此处是因为我们没有给它私钥）

[devopes@server4 ansible]$ ansible-playbook playbook.yml   ###报错
[devopes@server4 ansible]$ cd
[devopes@server4 ~]$ cd .ssh
[devopes@server4 .ssh]$ ls
id_rsa  id_rsa.pub  known_hosts
[devopes@server4 .ssh]$ ls
id_rsa  id_rsa.pub  known_hosts
[devopes@server4 .ssh]$ cp id_rsa.pub authorized_keys
[devopes@server4 .ssh]$ ll
total 16
-rw-r--r-- 1 devopes devopes  397 Aug 10 15:21 authorized_keys
-rw------- 1 devopes devopes 1675 Aug 10 09:56 id_rsa
-rw-r--r-- 1 devopes devopes  397 Aug 10 09:56 id_rsa.pub
-rw-r--r-- 1 devopes devopes  686 Aug 10 14:06 known_hosts

4、再次执行就可以发现成功

[devopes@server4 .ssh]$ cd
[devopes@server4 ~]$ cd ansible/
[devopes@server4 ansible]$ ansible-playbook playbook.yml   ##好了

5、编写playbook实现引用变量

1、建立模板目录，创建模板文件

[devopes@server4 ansible]$ mkdir templates
[devopes@server4 ansible]$ cd templates/
[devopes@server4 templates]$ ls
[devopes@server4 templates]$ cp ../files/httpd.conf .
[devopes@server4 templates]$ ls
httpd.conf
[devopes@server4 templates]$ mv httpd.conf httpd.conf.j2
[devopes@server4 templates]$ ls
httpd.conf.j2

2、进入.conf文件修改端口

[devopes@server4 templates]$ vim httpd.conf.j2  ##修改端口为{{ http_port }}

3、编辑playbook.yml文件

[devopes@server4 ansible]$ vim playbook.yml 
[devopes@server4 ansible]$ cat playbook.yml 
---
- hosts: webserver
  vars:
    http_port: 80
  tasks:
    - name: install httpd
      yum:
        name: httpd
        state: present

    - name: copy index.html
      copy:
        src: files/index.html
        dest: /var/www/html/index.html

    - name: configure httpd
      template:
        src: templates/httpd.conf.j2
        dest: /etc/httpd/conf/httpd.conf
        owner: root
        group: root
        mode: 644
      notify: restart httpd

    - name: start  httpd and firewalld
      service:
        name: "{{item}}"
        state: started
      loop:
        - httpd
        - firewalld

    - name: configure firewalld
      firewalld:
        service: http
        permanent: yes 
        immediate: yes
        state: enabled
 
  handlers:
    - name: restart httpd
      service:
        name: httpd
        state: restarted

- hosts: localhost
  become: no
  tasks:
    - name: test httpd
      uri:
        url: http://172.25.35.6
        status_code: 200

3、测试（在server5和server6上能发现httpd进程）

[devopes@server1 ansible]$ ansible-playbook playbook.yml     ###正确，没有报错
[root@server6 ~]# ps ax
[root@server5 ~]# ps ax

接下来我们再次更改端口进行验证，如下所示：

1、修改inventory文件

[devopes@server4 ansible]$ vim inventory 
[devopes@server4 ansible]$ cat inventory 
localhost
[test]
server5 http_host=172.25.35.5  

[prod]
server6 http_host=172.25.35.6

[webserver:children]
test
prod

2、更改端口

[devopes@server1 ansible]$ vim templates/httpd.conf.j2   ###更改端口为{{ http_host }}:{{ http_port }]

3、检查语法并执行.yml文件

[devopes@server1 ansible]$ ansible-playbook playbook.yml --syntax-check

playbook: playbook.yml
[devopes@server1 ansible]$ ansible-playbook playbook.yml    ###成功

4、分别在server5和server6上查看变量是否生效

[root@server5 tmp]$ cat /etc/httpd/conf/httpd.conf | grep Listen    
# Listen: Allows you to bind Apache to specific IP addresses and/or
# Change this to Listen on specific IP addresses as shown below to 
#Listen 12.34.56.78:80
Listen 172.25.35.5:80

[root@server6 tmp]$ cat /etc/httpd/conf/httpd.conf | grep Listen
# Listen: Allows you to bind Apache to specific IP addresses and/or
# Change this to Listen on specific IP addresses as shown below to 
#Listen 12.34.56.78:80
Listen 172.25.35.6:80

6、编写playbook实现采集远程主机的信息

1、编写file.yml文件

[devopes@server4 ansible]$ vim file.yml
[devopes@server4 ansible]$ cat file.yml 
---
- hosts: all
  tasks:
    - name: create file
      template:
        src: templates/file.j2
        dest: /tmp/file

2、创建模板

[devopes@server4 ansible]$ vim templates/file.j2
[devopes@server4 ansible]$ cat templates/file.j2 
主机名： {{ ansible_facts['hostname'] }}
主机IP： {{ ansible_facts['default_ipv4']['address'] }}
主机DNS： {{ ansible_facts['dns']['nameservers'] }}
boot分区： {{ ansible_facts['devices']['sda']['partitions']['sda1']['size'] }}
内核： {{ ansible_facts['kernel'] }}
内存空闲： {{ ansible_facts['memfree_mb'] }}

3、编写inventory文件（将上一步的localhost注释或者删除）

[devopes@server6 ansible]$ vim inventory 
[devopes@server6 ansible]$ cat inventory 
[test]
server5 http_host=172.25.35.5

[prod]
server6 http_host=172.25.35.6

[webserver:children]
test
prod

4、执行yml文件，发现正确

[devopes@server4 ansible]$ ansible-playbook file.yml   ###正确

5、分别在server5和server6上进行查看，发现可以正确查看

[root@server5 ~]# cat /tmp/file
主机名： server5
主机IP： 172.25.35.5
主机DNS： [u'114.114.114.114']
boot分区： 1.00 GB
内核： 3.10.0-514.el7.x86_64
内存空闲： 408

[root@server6 ~]# cat /tmp/file
主机名： server6
主机IP： 172.25.35.6
主机DNS： [u'114.114.114.114']
boot分区： 1.00 GB
内核： 3.10.0-514.el7.x86_64
内存空闲： 629

上面的DNS部分看起来不那么美观，要想美观我们可以在templates/file.j2文件中修改以下：

主机DNS： {{ ansible_facts['dns']['nameservers'] }}

修改完之后再次去执行.yml文件，再查看就OK了

7、编写playbook实现haproxy负载均衡

1、在server4上面进行授权

[root@server4 ansible]# vim /etc/sudoers
devopes   ALL=(ALL)       NOPASSWD: ALL

2、编辑playbook.yml文件

[devopes@server1 ansible]$ vim playbook.yml 
[devopes@server1 ansible]$ cat playbook.yml 
---
- hosts: webserver
  vars:
    http_port: 80
  tasks:
    - name: install httpd
      yum:
        name: httpd
        state: present

    - name: copy index.html
      copy:
        content: "{{ ansible_facts['hostname'] }}"
        dest: /var/www/html/index.html

    - name: configure httpd
      template:
        src: templates/httpd.conf.j2
        dest: /etc/httpd/conf/httpd.conf
        owner: root
        group: root
        mode: 644
      notify: restart httpd

    - name: start  httpd and firewalld
      service:
        name: "{{item}}"
        state: started
      loop:
        - httpd
        - firewalld

    - name: configure firewalld
      firewalld:
        service: http
        permanent: yes 
        immediate: yes
        state: enabled
 
  handlers:
    - name: restart httpd
      service:
        name: httpd
        state: restarted

- hosts: localhost
  tasks:
    - name: install haproxy
      yum:
        name: haproxy
        state: present

    - name: configure haproxy
      template:
        src: templates/haproxy.cfg.j2
        dest: /etc/haproxy/haproxy.cfg
      notify: restart haproxy

    - name: start haproxy
      service:
        name: haproxy
        state: started

  handlers:
    - name: restart haproxy
      service:
        name: haproxy
        state: restarted

3、在server4上安装haproxy服务，复制模板

[devope@server4 ansible]# yum list haproxy
Loaded plugins: product-id, search-disabled-repos, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Available Packages
haproxy.x86_64                        1.5.18-3.el7                        westos

[devopes@server4 ansible]# sudo yum install haproxy -y 
[devopes@server4 ansible]# cp /etc/haproxy/haproxy.cfg  templates/haproxy.cfg.j2

4、编辑模板，实验sever5和server6上的负载均衡

[devopes@server4 ansible]$ vim templates/haproxy.cfg.j2 
 55     timeout server          1m
 56     timeout http-keep-alive 10s
 57     timeout check           10s
 58     maxconn                 3000
 59     stats     uri    /status
 60 #---------------------------------------------------------------------
 61 # main frontend which proxys to the backends
 62 #---------------------------------------------------------------------
 63 frontend  main *:80
 64     acl url_static       path_beg       -i /static /images /javascript /styl    esheets
 65     acl url_static       path_end       -i .jpg .gif .png .css .js
 66 
 67 #    use_backend static          if url_static
 68     default_backend             app
 69 
 70 #---------------------------------------------------------------------
 71 # static backend for serving up images, stylesheets and such
 72 #---------------------------------------------------------------------
 73 backend app
 74          balance     roundrobin
 75          server  app1 172.25.35.5:80 check
 76          server  app2 172.25.35.6:80 check

5、执行.yml文件

[devopes@server1 ansible]$ ansible-playbook playbook.yml

6、浏览器监控测试（输入172.25.35.4/status）

7、浏览器轮循测试（输入172.25.35.4）

8、编写playbook实现将server7自动加入到负载均衡的集群中

1、创建用户并授权

[root@server7 ~]# useradd devopes
[root@server7 ~]# passwd devopes
[root@server7 ~]# vim /etc/sudoers
devopes ALL=(ALL)       NOPASSWD: ALL

2、在server4上ssh给sever7做免密

[devopes@server4 ansible]$ ssh-copy-id server7

3、在server4上编辑inventory文件

[devopes@server4 ansible]$ vim inventory 
[devopes@server4 ansible]$ cat inventory 
[test]
server5 http_host=172.25.35.5

[prod]
server6 http_host=172.25.35.6
server7 http_host=172.25.35.7

[webserver:children]
test
prod

4、编辑haproxy.cfg.j2的文件

[devopes@server4 ansible]$ vim templates/haproxy.cfg.j2 
 55     timeout server          1m
 56     timeout http-keep-alive 10s
 57     timeout check           10s
 58     maxconn                 3000
 59     stats     uri    /status
 60 #---------------------------------------------------------------------
 61 # main frontend which proxys to the backends
 62 #---------------------------------------------------------------------
 63 frontend  main *:80
 64     acl url_static       path_beg       -i /static /images /javascript /styl    esheets
 65     acl url_static       path_end       -i .jpg .gif .png .css .js
 66 
 67 #    use_backend static          if url_static
 68     default_backend             app
 69 
 70 #---------------------------------------------------------------------
 71 # static backend for serving up images, stylesheets and such
 72 #---------------------------------------------------------------------
 73  backend app
 74      balance     roundrobin
 75  {% for host in groups['webserver'] %}
    server {{ hostvars[host]['ansible_facts']['hostname'] }} {{ hostvars[host]['ansible_facts']['eth0']['ipv4']['address'] }}:80 check }}
 76 {% endfor %}

5、执行.yml文件，发现正确

[devopes@server4 ansible]$ ansible-playbook playbook.yml    ###正确