ansible-playbook模板的使用-when

需求

系统版本不同,根据系统版本使用对应的nginx模板

具体实现

1. 不知系统版本变量名称的情况下搜索变量名

[root@localhost ansible]# ansible all -m setup | grep version
       "ansible_bios_version": "VirtualBox",
       "ansible_distribution_major_version": "6",
       "ansible_distribution_version": "6.10",
       "ansible_kernel_version": "#1 SMP Mon Apr 27 15:30:33 UTC 2020",
       "ansible_product_version": "1.2",
           "version": {
           "version_info": [
       "ansible_python_version": "2.6.6",
       "ansible_bios_version": "VirtualBox",
       "ansible_distribution_major_version": "7",
       "ansible_distribution_version": "7.2",
       "ansible_kernel_version": "#1 SMP Mon Jan 25 22:07:14 UTC 2016",
       "ansible_product_version": "1.2",
           "version": {
           "version_info": [
       "ansible_python_version": "2.7.5",
           "version": "1.4.0"
               "version": "VirtualBox"
       "facter_facterversion": "3.1.4",
       "facter_kernelmajversion": "3.10",
       "facter_kernelversion": "3.10.0",
       "facter_puppetversion": "4.3.2",
           "version": "2.1.8"
       "ansible_bios_version": "VirtualBox",
       "ansible_distribution_major_version": "7",
       "ansible_distribution_version": "7.2",
       "ansible_kernel_version": "#1 SMP Mon Jan 25 22:07:14 UTC 2016",
       "ansible_product_version": "1.2",
           "version": {
           "version_info": [
       "ansible_python_version": "2.7.5",
           "version": "1.4.0"
               "version": "VirtualBox"
       "facter_facterversion": "3.1.4",
       "facter_kernelmajversion": "3.10",
       "facter_kernelversion": "3.10.0",
       "facter_puppetversion": "4.3.2",
           "version": "2.1.8"

通过分析可以看出ansible_distribution_major_version即为系统版本.

2. setup模块的filter过滤

[root@localhost playbook]# ansible all -m setup -a 'filter=ansible_distribution_major_version'
192.168.0.109 | SUCCESS => {
    "ansible_facts": {
        "ansible_distribution_major_version": "6",
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false
}
192.168.0.107 | SUCCESS => {
    "ansible_facts": {
        "ansible_distribution_major_version": "7",
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false
}
192.168.0.108 | SUCCESS => {
    "ansible_facts": {
        "ansible_distribution_major_version": "7",
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false
}

3. 编写nginx.yaml文件,添加when条件,具体如下:

[root@localhost playbook]# cat nginx.yaml
---
- hosts: all
  remote_user: root
  vars:
    - pkg1: nginx

  tasks:
    - name: install {{ pkg1 }}
      yum: name=nginx
    - name: copy template for centos6
      template: src=nginx.conf6.j2 dest=/etc/nginx/nginx.conf
      when: ansible_distribution_major_version == "6"
      notify: restartsrv
    - name: copy template for centos7
      template: src=nginx.conf7.j2 dest=/etc/nginx/nginx.conf
      when: ansible_distribution_major_version == "7"
      notify: restartsrv
    - name: start {{ pkg1 }} server
      service: name=nginx state=started enabled=yes

  handlers:
    - name: restartsrv
      service: name=nginx state=restarted

4. 准备不同系统版本的nginx模板文件

[root@localhost playbook]# ls templates/
nginx.conf6.j2  nginx.conf7.j2

5. 修改模板文件内容,详见worker_processes参数配置:

[root@localhost playbook]# cat templates/nginx.conf6.j2
user nginx;
worker_processes {{  ansible_processor_vcpus+4 }};

[root@localhost playbook]# cat templates/nginx.conf7.j2
user daemon;
worker_processes {{ ansible_processor_vcpus*2 }};

    server {
        listen       {{ port }}  default_server;
        listen       [::]:{{ port }} default_server;
    }
}

6. 执行

[root@localhost playbook]# ansible-playbook nginx.yaml