[ansible] playbook运用

一、复习playbook剧本

---
- name: first play for install nginx   #设置play的名称
  gather_facts: false                  #设置不收集facts信息
  hosts: webservers:dbservers          #指定执行此play的远程主机组
  remote_user: root                    #指定执行此play的用户
  tasks:                               #指定此play的任务列表
  - name: disabled firewalld
    service: name=firewalld  state=stopped  enabled=no
  - name: disable selinux
    command: '/sbin/setenforce 0'
    ignore_errors: yes
  - name: disabled selinux forever
    replace: path=/etc/selinux/config  regexp=enforcing  replace=disabled  after=loaded
  - name: mount cdrom
    mount: src=/dev/sr0 path=/mnt fstype=iso9660 state=mounted
  - name: install pkgs
    yum: name=pcre-devel,zlib-devel,openssl-devel,gcc,gcc-c++,make state=latest
  - name: create nginx user
    user: name=nginx create_home=no shell=/sbin/nologin
  - name: unarchive nginx package
    unarchive: copy=yes src=/etc/ansible/nginx/nginx-1.24.0.tar.gz dest=/opt/
  - name: install nginx by source
    shell: chdir=/opt/nginx-1.24.0/ ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx --with-http_stub_status_module && make && make install
  - name: create link file for nginx
    file: state=link src=/usr/local/nginx/sbin/nginx path=/usr/local/sbin/nginx
  - name: create nginx service file
    copy: src=nginx.service dest=/lib/systemd/system/nginx.service
  - name: start nginx
    service: name=nginx state=started enabled=yes

二、playbook的定义、引用变量

2.1 基础变量的定义与引用

在yaml文件中，我们可以在初始配置的模块中用var去定义变量的存在，变量的格式为key:value,以此来确定该变量在剧本中的存在

vim test1.yaml
---
- name: this is a play for testing variables
  hosts: dbservers
  remote_user: root
  vars:
   filename: abc.txt
  tasks:
   - name: touch a test file
     file: path=/opt/{
  {filename}} state=touch
 
 
ansible-playbook test1.yaml

2.2 引用fact信息中的变量  

首先我们知道  使用 ansible 组  -m setup   可以收集该组中所有的节点信息 ，

所以setup中fact'信息，有时候会剧本编写中需要，而fact的信息也是可以通过变量的方式进行调用

vim test2.yaml
---
- name: this is a playbook for quote variate
  hosts: dbservers
  remote_user: root
  tasks:
   - name: reading setup fact variate
     debug: msg={
  {ansible_date_time.weekday}}
~                                                 

三、playbook中的when条件判断和变量循环使用 

3.1 when条件判断 

#选用filter=ansible_default_ipv4中的address作为when条件进行测试
ansible all -m setup -a 'filter=ansible_default_ipv4'

vim test3.yaml
---
- name: this is when test playbook
  hosts: all
  remote_user: root
  tasks:
   - name: test when
     debug: msg='判断位置'
     when: ansible_default_ipv4.address == "192.168.136.198"
 
 
ansible-playbook test3.yaml

除此之外 when条件还可以通过 ！=（不等于条件来进行判断） 

vim test3.yaml
---
- name: this is when test playbook
  hosts: all
  remote_user: root
  tasks:
   - name: test when
     debug: msg='判断位置'
     when: ansible_default_ipv4.address != "192.168.136.198"
ansible-playbook test3.yaml

四、变量循环 

（1）with_item 单循环输出

vim test4.yaml
---
- name: item test
  hosts: dbservers
  remote_user: root
  gather_facts: no
  tasks:
   - debug:
       msg: "{
  {item}}"
     with_items: [a, b, c, d]
 
ansible-playbook test4.yaml

 当列表为两个时。with_item的输出方式：

vim test4.yaml
---
- name: item test
  hosts: dbservers
  remote_user: root
  gather_facts: no
  tasks:
   - debug:
       msg: "{
  {item}}"
     with_items:
      - [a, b, c, d]
      - [1 ,2, 3, 4]
ansible-playbook test4.yaml                      

（2）with_list  每组列表一起循环的输出 

---
- name: item test
  hosts: dbservers
  remote_user: root
  gather_facts: no
  tasks:
   - debug:
       msg: "{
  {item}}"
     with_list:
      - [a, b, c, d]
      - [1 ,2, 3, 4]
~                                                                                                                                           
~                            

（3）with_together 同一列表位置数据组合输出的循环 

---
- name: item test
  hosts: dbservers
  remote_user: root
  gather_facts: no
  tasks:
   - debug:
       msg: "{
  {item}}"
     with_together:
      - [a, b, c, d]
      - [1 ,2, 3, 4]
~                        

---
- name: item test
  hosts: dbservers
  remote_user: root
  gather_facts: no
  tasks:
   - debug:
       msg: "{
  {item}}"
     with_together:
      - [a, b, c, d]
      - [1 ,2, 3, 4]
      - [A, B, C]

（4） with_nested 列表数据循环匹配的循环（根据列表个数定义有多少层的循环） 

---
- name: item test
  hosts: dbservers
  remote_user: root
  gather_facts: no
  tasks:
   - debug:
       msg: "{
  {item}}"
     with_nested:
      - [a, b, c, d]
      - [1 ,2, 3, 4]
~                      

四种迭代循环方式的总结

whith_items:  { {item}}会把所有的列表展开进行遍历输出，with_flattened也可以替代with_items

 with_list:    { {item}}会把每个列表当作一个整体输出。如果每个列表中只有一个值，则效果与with items一致。loop也可以替代ith

 with_together: { {item}}引用时会把每个列表相同位置的值对齐合并后输出

with nested:{ {item}}引用时会把每个列表的值两两组合循环输出

五、Templates 模块

Jinja是基于Python的模板引擎。Template类是Jinja的一个重要组件，可以看作是一个编译过的模板文件，用来产生目标文本，传递Python的变量给模板去替换模板中的标记。 

 本次我们以改变apche的配置文件为例，来展现Templates模块的运用

（1）先准备一个以 .j2 为后缀的 template 模板文件，设置引用的变量 

#如果没有相关的httpd的配置文件，可以先yum按住一个httpd的服务，取其主配置文件
cp httpd.conf /etc/ansible/httpd/httpd.conf.j2
 
vim /etc/ansible/httpd/httpd.conf.j2
Listen {
  {http_port}}				#42行，修改
ServerName {
  {server_name}}			#95行，修改
DocumentRoot "{
  {root_dir}}"          #119行，修改

（2） 修改主机清单文件，使用主机变量定义一个变量名相同，而值不同的变量 

vim /etc/ansible/hosts       
[webservers]
192.168.136.197 http_port=192.168.136.197:80 server_name=www.test1.com:80 root_dir=/etc/httpd/htdocs
 
[dbservers]
192.168.136.198 http_port=192.168.136.198:80 server_name=www.test2.com:80 root_dir=/etc/httpd/htdocs

 此外如果没有做DNS解析域名，还需要对主机名进行映射 ：

vim /etc/hosts
 
192.168.73.106 www.test1.com
192.168.73.107 www.test2.com

（3）编写 playbook 

mkdir /etc/ansible/templates
vim apache.yaml
---
- hosts: all
  remote_user: root
  vars:
    - package: httpd
    - service: httpd
  tasks:
    - name: install httpd package
      yum: name={
  {package}} state=latest
    - name: install configure file
      template: src=/etc/ansible/httpd/httpd.conf.j2 dest=/etc/httpd/conf/httpd.conf
      notify:
        - restart httpd
    - name: create root dir
      file: path=/etc/httpd/htdocs state=directory
    - name: start httpd server
      service: name={
  {service}} enabled=true state=started
  handlers:
    - name: restart httpd
      service: name={
  {service}} state=restarted
 
 
ansiable-playbook apache.yaml

​​​​​​​

六、Tags 

可以在一个playbook中为某个或某些任务定义“标签”，在执行此playbook时通过ansible-playbook命令使用--tags选项能实现仅运行指定的tasks。
playbook还提供了一个特殊的tags为always。作用就是当使用always作为tags的task时，无论执行哪一个tags时，定义有always的tags都会执行。

6.1 单标签的使用

vim test10.yaml
---
- name: this is a play for testing variables
  hosts: dbservers
  remote_user: root
  vars:
   filename: abc.txt
  tasks:
   - name: position 1
     debug:
       msg: 'ls /opt'
     tags:
      - only
   - name: position 2
     debug:
       msg: 'ls /mnt'
 
ansible-playbook test1.yaml --tags="only"

6.2 多标签的运用

---
- name: this is a play for testing variables
  hosts: dbservers
  remote_user: root
  vars:
   filename: abc.txt
  tasks:
   - name: position 1
     debug:
       msg: '测试标签1'
     tags:
      - one
   - name: position 2
     debug:
       msg: '测试标签2'
     tags:
      - two
 
   - name: position 3
     debug:
       msg: '测试标签3'
     tags:
      - one

6.3 通用标签always的运用  

---
- name: this is a play for testing variables
  hosts: dbservers
  remote_user: root
  vars:
   filename: abc.txt
  tasks:
   - name: position 1
     debug:
       msg: '测试标签1'
     tags:
      - one
   - name: position 2
     debug:
       msg: '测试通用标签always'
     tags:
      - always
 
   - name: position 3
     debug:
       msg: '测试标签3'
     tags:
      - one