哈喽大家好，我是koten，本篇文章给大家介绍jinja2模板，这是python的全功能模板引擎。在Ansible中，通常会使用jinja2模板来修改被管理主机的配置文件（saltstack中也会用到）
Ansible中使用的jinja2模板其实就是使用template模块，该模块与copy模块一样，都有复制管理机的配置文件到客户机的作用，区别在于template模块可以获取到文件中的变量，而copy则是原封不动把文件内容复制过去。如：我们想把脚本中的变量名改成主机名，如果使用copy推送的就是{
{ ansible_fqdn }}，如果使用template，则会变成对应的主机名。
需要注意的是，Ansible允许jinja2模板中使用条件判断和循环，但是不允许在playbook中使用，只能在传输的文件中使用。
Ansible Jinja2模板使用
1、基本语法
1、playbook文件使用template模块 2、模板文件里面变量使用{{名称}}，比如{{ port }}或使用facts
2、Jinja2模板逻辑判断
#循环表达式 {% for i in EXPR %} {% endfor %} #条件判断 {% if EXPR %} {% elif EXPR %} {% else %} {% endif %} #注释 {# COMMENT #}
3、Jinja2示例
1、编辑playbook
[root@Ansible test]# cat jinja2.yml - hosts: web_group tasks: - name: copy template file template: src: motd.j2 dest: /etc/motd
2、准备motd.j2文件
[root@Ansible test]# cat motd.j2 Welcome to {{ ansible_fqdn }} This system total mem is : {{ ansible_memtotal_mb }} MB This system free mem is : {{ ansible_memfree_mb }} MB
3、执行playbook并查看效果
[root@Ansible test]# ansible-playbook jinja2.yml PLAY [web_group] *************************************************************** TASK [Gathering Facts] ********************************************************* ok: [web01] ok: [web02] TASK [copy template file] ****************************************************** changed: [web01] changed: [web02] PLAY RECAP ********************************************************************* web01 : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 web02 : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 [root@Ansible test]# ansible web_group -a 'cat /etc/motd' web01 | CHANGED | rc=0 >> Welcome to Web01 This system total mem is : 972 MB This system free mem is : 441 MB web02 | CHANGED | rc=0 >> Welcome to Web02 This system total mem is : 972 MB This system free mem is : 84 MB
Ansible Jinja2管理nginx
Ansible使用jinja2的for循环表达式渲染出nginx负载均衡的配置文件
1、编辑playbook
[root@Ansible test]# cat lb.yml - hosts: lb_group vars: http_port: 80 server_name: www.koten.vip tasks: - name: copy template: src: proxy_7.conf.j2 dest: /etc/nginx/conf.d/proxy_7.conf notify: reload nginx handlers: - name: reload nginx systemd: name: nginx state: reloaded
2、准备配置文件
[root@Ansible test]# cat proxy_7.conf.j2 upstream {{ server_name }} { {% for n in range(21) %} server 172.16.1.{{ n }}:{{ http_port }} {% endfor %} } server{ listen 80; server_name {{ server_name }}; location / { root /code index index.html proxy_pass http://{{ server_name }} proxy_set_header Host $http_host } }
3、执行playbook并查看客户机上的效果
[root@Ansible test]# ansible-playbook lb.yml PLAY [lb_group] **************************************************************** TASK [Gathering Facts] ********************************************************* ok: [lb00] ok: [lb01] ok: [lb02] TASK [copy] ******************************************************************** changed: [lb01] changed: [lb00] changed: [lb02] RUNNING HANDLER [reload nginx] ************************************************* changed: [lb00] changed: [lb02] changed: [lb01] PLAY RECAP ********************************************************************* lb00 : ok=3 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 lb01 : ok=3 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 lb02 : ok=3 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
查看效果
[root@LB00 ~]# cat /etc/nginx/conf.d/proxy_7.conf upstream www.koten.vip { server 172.16.1.0:80 server 172.16.1.1:80 server 172.16.1.2:80 server 172.16.1.3:80 server 172.16.1.4:80 server 172.16.1.5:80 server 172.16.1.6:80 server 172.16.1.7:80 server 172.16.1.8:80 server 172.16.1.9:80 server 172.16.1.10:80 server 172.16.1.11:80 server 172.16.1.12:80 server 172.16.1.13:80 server 172.16.1.14:80 server 172.16.1.15:80 server 172.16.1.16:80 server 172.16.1.17:80 server 172.16.1.18:80 server 172.16.1.19:80 server 172.16.1.20:80 } server{ listen 80; server_name www.koten.vip; location / { root /code index index.html proxy_pass http://www.koten.vip proxy_set_header Host $http_host } }
Ansible Jinja2管理keepalived
ansible使用jinja模板的if判断表达式渲染出keepalived高可用配置文件，并推送到lb主机上
1、编辑playbook
[root@Ansible test]# cat keepalived.yml - hosts: lb_group tasks: - name: copy file template: src: keepalived.conf.j2 dest: /etc/keepalived/keepalived.conf notify: restart keepalived when: (ansible_hostname is match "LB01") or (ansible_hostname is match "LB02") handlers: - name: restart keepalived systemd: name: keepalived state: restarted when: (ansible_hostname is match "LB01") or (ansible_hostname is match "LB02")
2、编写keepalived配置文件
可以看着keepalive master配置文件和keepalive backup配置文件参考着编写
[root@Ansible test]# cat keepalived.conf.j2 global_defs { router_id {{ ansible_fqdn }} } vrrp_instance VI_1 { {% if ansible_fqdn == "LB01" %} state MASTER priority 150 {% else %} state BACKUP priority 100 {% endif %} interface eth0 virtual_router_id 50 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.0.0.3 } }
3、执行playbook并查看效果
[root@Ansible test]# ansible-playbook keepalived.yml PLAY [lb_group] **************************************************************************************** TASK [Gathering Facts] ********************************************************************************* ok: [lb02] ok: [lb00] ok: [lb01] TASK [copy file] *************************************************************************************** skipping: [lb00] changed: [lb02] changed: [lb01] RUNNING HANDLER [restart keepalived] ******************************************************************* changed: [lb01] changed: [lb02] PLAY RECAP ********************************************************************************************* lb00 : ok=1 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 lb01 : ok=3 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 lb02 : ok=3 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 [root@LB01 ~]# cat /etc/keepalived/keepalived.conf global_defs { router_id LB01 } vrrp_instance VI_1 { state MASTER priority 150 interface eth0 virtual_router_id 50 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.0.0.3 } } [root@LB02 ~]# cat /etc/keepalived/keepalived.conf global_defs { router_id LB02 } vrrp_instance VI_1 { state BACKUP priority 100 interface eth0 virtual_router_id 50 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.0.0.3 } }
我是koten，10年运维经验，持续分享运维干货，感谢大家的阅读和关注！
