앵앵

ㅁ when_dict

- dictionary : key:value.형태의 자료

 users (dictionary) 라면,   

alice(key) :          name: Alice (value)  phone: 123-456(value) 

bob(key)  :          name: bob name(value) phone: 678-910(value)

- 실행결과

TASK [user.key is value] ***************************************************************************************************************************

MSG:

 bob is bob name  678-910 

MSG:

 alice is Alice  123-456 

(참조: - https://docs.ansible.com/ansible/latest/user_guide/playbooks_conditionals.html#the-when-statement)

ㅁWhen조건

 - 조건이 참(true) 일경우 task 실행, 거짓(false)일 경우 task 미실행

ㅁ when활용

- task요약 : 

- name: /etc/passwd | use cut command

 ▶ cut --delimiter=':' --fields=1 /etc/passwd 수행하고, register를 이용해 usernames_result 변수 선언

- name: command set_fact

▶ set_fact에  username_list == usernames_result.stdout_lines 선언

- name: result refered to username_list

▶ 조건문 when 실행,   'testuser1'이  username_list에 있는지 in 연산자를 사용해 확인

---

- name: command result 

  hosts: localhost

  tasks:

   - name: /etc/passwd | use cut command

     command: cut --delimiter=':' --fields=1 /etc/passwd

     register: usernames_result

   - name: username_result debug

     debug:

        var: usernames_result

   - name: command set_fact

     set_fact:

       username_list: "{{ usernames_result.stdout_lines }}"

   - name: result refered to username_list

     debug:

       msg: this server exists test1

     when: "'testuser1' in username_list"

- 결과 (when이  true일 경우)

[root@system1 yaml]# ansible-playbook get-users.yml

PLAY [command result] ************************************************************************************

TASK [Gathering Facts] ***********************************************************************************

ok: [localhost]

TASK [/etc/passwd | use cut command] *********************************************************************

changed: [localhost]

TASK [username_result debug] *****************************************************************************

-- 생략 

TASK [command set_fact] **********************************************************************************

ok: [localhost]

TASK [result refered to username_list] *******************************************************************

ok: [localhost] => {}

MSG:

this server exists test1

PLAY RECAP ***********************************************************************************************

localhost                  : ok=5    changed=1    unreachable=0    failed=0   

- 결과2 (when이 false, 즉 testuser1이 username_list 內 없을 경우)

 ▶ when이 있는 task는  skipping이 출력됨

  . skipping : when이 지정한 조건을 만족하지 않았을때 하는 동작 

[root@system1 yaml]# ansible-playbook get-users.yml

PLAY [command result] ************************************************************************************

TASK [Gathering Facts] ***********************************************************************************

ok: [localhost]

TASK [/etc/passwd | use cut command] *********************************************************************

changed: [localhost]

TASK [username_result debug] *****************************************************************************

-- 생략 

TASK [command set_fact] **********************************************************************************

ok: [localhost]

TASK [result refered to username_list] *******************************************************************

skipping: [localhost]

PLAY RECAP ***********************************************************************************************

localhost                  : ok=4    changed=1    unreachable=0    failed=0   

ㅁ 진자2(jinja2)?

  - 진자2 템플릿 엔진으로 앤서블의 변수 확장으로 주로 씀

ㅁ 진자2 변수 활용방법

 - 진자2는 반드시 {{,}}로 묶어서 사용하며,  변수를 활용할시에는 " "로 묶어서 사용해야함

 - playbook 예제

---

- name: vars_ jinja

  hosts: localhost

  vars:

    my_var: song

  tasks:

    - name: my_var debug

      debug:

        msg: " vars values is {{ my_var }}"

           ---> 진자2 라인은  "{{ 변수 }}"   로 묶었다

 - playbook result

[root@system1 yaml]# ansible-playbook debug-var.yml

PLAY [vars_ jinja] ***************************************************************************************

TASK [Gathering Facts] ***********************************************************************************

ok: [localhost]

TASK [my_var debug] **************************************************************************************

ok: [localhost] => {}

MSG:

 vars values is song

PLAY RECAP ***********************************************************************************************

localhost                  : ok=2    changed=0    unreachable=0    failed=0   

( 참조 : https://docs.ansible.com/ansible/latest/user_guide/playbooks_conditionals.html#register-variables)

- ansible register:  플레이북에서의 결과를 변수로 정하기 위해 사용되는 모듈

ㅁ Playbook 예제

- /home하위에 디렉토리 변수 저장

1) yaml

- name: registered variable usage as a loop list
  hosts: all
  tasks:

    - name: retrieve the list of home directories
      command: ls /home
      register: home_dirs

    - name: debug ls /home
      debug:
      var: home_dirs

2) 결과

- stdout_lines를 확인가능

PLAY [registered variable usage as a loop list] ****************************************************************************************************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************************

ok: [localhost]

TASK [retrieve the list of home directories] ***************************************************************************************************************************

changed: [localhost]

TASK [debug  ls /home] ***************************************************************************************************************************

ok: [localhost] => {

    "home_dirs": {

        "changed": true, 

        "cmd": [

            "ls", 

            "/home"

        ], 

        "delta": "0:00:00.008900", 

        "end": "2018-11-26 23:07:41.673464", 

        "failed": false, 

        "rc": 0, 

        "start": "2018-11-26 23:07:41.664564", 

        "stderr": "", 

        "stderr_lines": [], 

        "stdout": "david\njohn\nlost+found\npeter\nsarah\ntestuser1\ntestuser2", 

        "stdout_lines": [

            "david", 

            "john", 

            "lost+found", 

            "peter", 

            "sarah", 

            "testuser1", 

            "testuser2"

        ]

    }

}

ㅁ cut 명령예시

[root@system1 ~]# cut --delimiter=':' --fields=1 /etc/passwd| head -5

root

bin

daemon

adm

lp

- delimiter : 구분자

- fields : 출력할 필드