[Ansible] 04. When, Block, Hendler

[Ansible] 04. When, Block, Hendler

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🔔 자세한 모듈 내용은 아래 문서를 참고

모듈 내용 : https://docs.ansible.com/ansible/latest/collections/ansible/builtin/index.html#modules

예제 Github : https://github.com/revenge1005/Ansible_study

🔔 When, Block, Hendler

구분	설명
When	조건문, 조건이 참(True)일 경우 Task 실행, 거짓(False)일 경우 Task 미실행
Block	Task 그룹
Handler	조건부 형식 중에 하나 (조건부 형식이란, if 앞의 테스크가 동작하거나 또는 조건에 맞는다면 handler를 실행한다) Task에서 notify를 이용하여 handler의 name을 매개변수로 전달하여 알린다. 모든 Task가 모두 실행된 후에 Handler가 실행된다. 여러 차레 알람을 받아도 핸들러는 한 번만 실행된다. 플레이에 여러 handler를 포함하면, 해당 핸들러는 알림 순서가 아니라, handler 섹션에 정의된 순서대로 항상 실행된다.

🔔 Managed 노드의 OS 정보 확인

$ ansible all -m gather_facts --limit node01 | grep ansible_distribution
        "ansible_distribution": "Rocky",
        "ansible_distribution_file_parsed": true,
        "ansible_distribution_file_path": "/etc/redhat-release",
        "ansible_distribution_file_variety": "RedHat",
        "ansible_distribution_major_version": "8",
        "ansible_distribution_release": "Green Obsidian",
        "ansible_distribution_version": "8.5",

📜 예제1. 다른 OS 별로 Apache 설치 (Wen 사용)

(1) Ubuntu 노드 추가

$ cat <<EOF >> /etc/hosts
192.168.219.203  node03  node03.test.com
EOF

ssh-copy-id -i ~/.ssh/id_ed25519.pub node03

cat <<EOF >> inventory
node03
EOF

$ ansible -m ping all

(2) Playbook 작성

$ cat <<EOF > install_apache2.yml
---

- hosts: all
  become: true
  tasks:

  - name: update repository index (Ubuntu)
    apt:
      update_cache: yes
    when: ansible_distribution == "Ubuntu" and ansible_distribution_version == "20.04"

  - name: install apache2 package (Ubuntu)
    apt:
      name: apache2
      state: latest
    when: ansible_distribution in ["Ubuntu", "Debiain"]

  - name: apache2 Service Start & enable (Ubuntu)
    service:
      name: apache2
      state: started
      enabled: yes
    when: ansible_distribution in ["Ubuntu", "Debiain"]

  - name: update repository index (Rocky)
    dnf:
      update_cache: yes
    when: ansible_distribution == "Rocky"

  - name: install httpd packge (Rocky)
    dnf:
      name: httpd
      state: latest
    when: ansible_distribution == "Rocky"

  - name: httpd Service Start & enable (Rocky)
    service:
      name: httpd
      state: started
      enabled: yes
    when: ansible_distribution == "Rocky"
EOF

$ ansible-playbook install_apache2.yml

📜 예제2. Handler 예시

(1) 구성

$ # tree .
.
├── ansible.cfg
├── files
│   └── index.html
├── install_apache3.yml
└── inventory

# cat files/index.html
<h1>Hello World!!!</h1>

(2) Playbook 작성

$ cat <<EOF > install_apache3.yml
---
- name: Install Apache and Upload my Home Page
  hosts: all
  become: yes

  vars:
    source_file: ./files/index.html
    destin_file: /var/www/html/

  tasks:

  - name: Install Apache WEB Server
    dnf:
      name: httpd
      state: latest
    when: ansible_distribution == "Rocky"

  - name: Copy HomePage file to WEB Server
    copy:
      src: "{{ source_file  }}"
      dest: "{{ destin_file  }}"
      mode: 0555
    when: ansible_distribution == "Rocky"
    notify: Restart Apache

  - name: Start WEB Server service
    service:
      name: httpd
      state: started
      enabled: yes
    when: ansible_distribution == "Rocky"

  handlers:
  - name: Restart Apache
    service:
      name: httpd
      state: restarted
EOF

$ ansible-playbook install_apache3.yml

📜 예제3. block, When 예제

(1) 구성

$ tree .
.
├── ansible.cfg
├── files
│   └── index.html
├── install_apache4.yml
└── inventory

$ cat files/index.html
<h1>Hello World!!!</h1>

(2) Playbook 작성

$ cat <<EOF > install_apache4.yml
---
- name: Install Apache and Upload my Home Page
  hosts: all
  become: yes

  vars:
    source_file: ./files/index.html
    destin_file: /var/www/html/

  tasks:

  - name: Check and Print Linux Version
    debug:
      var: ansible_os_family

  - block:   # ======Block for RedHat======

      - name: Install Apache WEB Server for RedHat
        yum:
          name: httpd
          state: latest

      - name: Copy HomePage file to WEB Server
        copy:
          src: "{{ source_file  }}"
          dest: "{{ destin_file  }}"
          mode: 0555
        notify: Restart Apache RedHat

      - name: Start WEB Server service for RedHat
        service:
          name: httpd
          state: started
          enabled: yes

    when: ansible_os_family == "RedHat"

  - block:   # ======Block for Debian======

      - name: Install Apache WEB Server for Debian
        apt:
          name: apache2
          state: latest

      - name: Copy HomePage file to WEB Server
        copy:
          src: "{{ source_file  }}"
          dest: "{{ destin_file  }}"
          mode: 0555
        notify: Restart Apache Debian

      - name: Start WEB Server service for Debian
        service:
          name: apache2
          state: started
          enabled: yes

    when: ansible_os_family == "Debian"

  handlers:
  - name: Restart Apache RedHat
    service:
      name: httpd
      state: restarted

  - name: Restart Apache Debian
    service:
      name: apache2
      state: restarted
EOF

$ ansible-playbook install_apache4.yml

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