【IT Notes】RHCE測驗第八題 USE ROLES FROM ANSIBLE GALAXY

 Create a playbook called /home/student/ansible/roles.yml with the following requirements:

• The playbook contains a play that runs on hosts in the balancers host group and uses the balancer role.

  • This role configures a service to load balance web server requests between hosts in the webservers host group.
  • Browsing to hosts in the balancers host group (for example http://node5.example.com/) produces the following output:

    Welcome to node3.example.com on 172.25.250.12

  • Reloading the browser produces output from the alternate web server:

    Welcome to node4.example.com on 172.25.250.13

• The playbook contains a play that runs on hosts in the webservers host group and uses the phpinfo role.

• Browsing to hosts in the webservers host group with the URL /hello.php produces the following output:

  Hello PHP World from FQDN

  where FQDN is the fully qualified domain name of the host.

• For example, browsing to http://node3.example.com/hello.php, produces the following output:

  Hello PHP World from node3.example.com

  along with various details of the PHP configuration including the version of PHP that is installed.

• Similarly, browsing to http://node4.example.com/hello.php, produces the following output:

  Hello PHP World from node4.example.com

  along with various details of the PHP configuration including the version of PHP that is installed.

【題前說明】

這題落落長寫了一大堆看似很嚇人，卻是解題過程最短的，乍看之下以為要做什麼大工程，其實就只是把第六題下載並安裝好的兩個roles分別套用到兩個群組上：balancer套用在balancers群組上；phpinfo套用在webservers群組，用的指令是ansible-galaxy，最後還要自己驗證一下結果。

一．解題過程：

[student@workstation ansible]$ vim roles.yml

---
- name: gather facts
  hosts: webservers

- name: config balancer
  hosts: balancers
  roles:
    - balancer

- name: config phpinfo
  hosts: webservers
  roles:
    - phpinfo

二．驗證結果

[student@workstation ansible]$ ansible-playbook -C roles.yml　\\試跑看看是否正常

[student@workstation ansible]$ ansible-playbook roles.yml　\\沒問題就正式跑

驗證balancer的付載平衡功能是否正常，用curl指令來檢查node5，每次戳它都會自動切換就表示成功了。

[student@workstation ansible]$ curl node5

Welcome to node3 on 172.25.250.12

[student@workstation ansible]$ curl node5

Welcome to node4 on 172.25.250.13

用瀏覽器打開node3和node4，看看是否有把訊息秀出來就知道是否成功。

三．恢復解題前的環境

恢復解題前的方式就是用ansible-galaxy，把剛剛裝過的roles都卸載即可。

[student@workstation ansible]$ vim 08-lab-galaxy-role-stop.yml

---
- name: gater facts
  hosts: webservers, balancers

- name: remove role balancer
  hosts: balancers
  tasks:
    - name: remove role balancer
      shell: ansible-galaxy remove balancer

- name: remove role phpinfo
  hosts: webservers
  tasks:
    - name: remove role phpinfo
      shell: ansible-galaxy remove phpinfo

[student@workstation ansible]$ ansible-playbook 08-lab-galaxy-role-stop.yml