Ansible 반복문과 조건문

#1 이론

   1. 반복문

• Ansible 플레이북에서 작업이나 코드 일부를 여러 번 반복 사용
• loop 지시문에 반복할 값 명시, 순서대로 한번 씩 item 변수에 삽입
• loop안에 있는 요소는 위에서부터 순차적으로 하나씩 삽입
• 모두 다 넣으면 완료
• item : 반복문에서 사용하는 전용 변수

---
- name: Apache and Tomcat are running
service:
name: "{{ item }}"
state: started
loop:
- httpd
- tomcat

 

   2. 조건문

• when : 테스트 조건이 값으로 입력
• 조건을 충족치 않으면 건너뜀
• 가장 마지막에 두는 것이 일반적

 

#2 실습

   1. 반복문

• loop-exam1.yaml
• - name: Working with loop module
    hosts: seoul
    gather_facts: false
    tasks:
      - name: Iterate over hashes
        debug:
          msg:
            - "Hello '{{ item.fname }}', nice to meet you"
            - "Your last name as per our record is '{{ item.lname }}'"
            - "Your country of residence is '{{ item.location }}'"
        loop:
          - { fname: 'deepak', lname: 'prasad', location: 'India' }
          - { fname: 'amit', lname: 'kumar', location: 'Argentina' }
          - { fname: 'rahul', lname: 'sharma', location: 'Canada' }
          - { fname: 'vivek', lname: 'mittal', location: 'Brazil' }
          - { fname: 'chul', lname: 'jeong', location: 'Korea' }
• loop-exam2.yaml
• - name: Working with loop module
    hosts: seoul
    gather_facts: false
    tasks:
      - name: Iterate over dictionary
        debug:
          msg:
            - "The {{ item.key }} of your car is {{ item.value }}"
        loop: "{{ my_car | dict2items }}"
        vars:
          my_car:
            Color: Black
            Model: Benz GLC400
            Transition: Manual
            Price: $200,000
• loop-register.yaml
• - name: Loop Register Test
    gather_facts: no
    hosts: seoul
    tasks:
      - name: Looping Task
        shell: "echo This is my item: {{ item }}"
        loop:
          - tiger
          - lion
        register: results1
  
      - name: Show results variable
        debug:
          var: results1
• create_user.yaml
• - hosts: seoul
    become: yes
    tasks:
      - name: Create new users
        user:
          name: '{{ item.name }}'
          uid: '{{ item.uid }}'
          state: present
        loop:
          - name: park
            uid: 1020
          - name: kim
            uid: 1030
          - name: lee
            uid: 1040

vim loop-exam1.yaml
ansible-playbook loop-exam1.yaml

vim loop-exam2.yaml
ansible-playbook loop-exam2.yaml

vim loop-register.yaml
ansible-playbook loop-register.yaml

vim create_user.yaml
ansible-playbook create_user.yaml

loop-exam1	loop-exam2
loop-register	create_user

 

    2. 조건문

• when-exam1.yaml
• - name: when conditional operator
    hosts: seoul
    gather_facts: false
    vars:
      x: 10
      y: 15
      list: [10, 20, 30]
    tasks:
      - debug:
          msg:
            - "The value of x is {{ x }} and the value of y is {{ y }}"
            - "Our list contains: {{ list }}"
        when: x == y
  
      - debug:
          msg: "x is present in the list"
        when: x in list
• when-exam2.yaml
• - name: List when test
    hosts: seoul
    vars:
      supported_distros:
        - RedHat
        - CentOS
        - Fedora
        - Ubuntu
    tasks:
      - name: debug
        debug:
          msg: "{{ ansible_distribution }}"
  
      - name: Install httpd using yum
        yum:
          name: httpd
          state: present
        when: ansible_distribution in supported_distros
• when-exam3.yaml
• - hosts: seoul
    vars:
      user: nana
    tasks:
      - name: Check if file already exists
        command: ls /home/{{ user }}/myfile
        register: file_exists
        ignore_errors: yes
  
      - name: create file for user
        file:
          path: /home/{{ user }}/myfile
          state: touch
        when: file_exists is failed
  
      - name: show message if file exists
        debug:
          msg: The user file already exists.
        when: file_exists is succeeded

vim when-exam1.yaml
ansible-playbook when-exam1.yaml

vim when-exam2.yaml
ansible-playbook when-exam2.yaml

vim when-exam3.yaml
ansible-playbook when-exam3.yaml

 

#3 남은 것!

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