Ansible Playbooks Phần 3: Conditionals, Loops và Tags

tasks:
  - name: Install Apache on Debian/Ubuntu
    apt:
      name: apache2
      state: present
    when: ansible_os_family == "Debian"

  - name: Install Apache on RedHat/CentOS
    yum:
      name: httpd
      state: present
    when: ansible_os_family == "RedHat"

  - name: Start service only on production
    service:
      name: nginx
      state: started
    when: env == "production"

tasks:
  - name: Install package on Ubuntu 20.04
    apt:
      name: nginx
      state: present
    when:
      - ansible_distribution == "Ubuntu"
      - ansible_distribution_version == "20.04"

  # Hoặc viết trên một dòng
  - name: Same as above
    apt:
      name: nginx
      state: present
    when: ansible_distribution == "Ubuntu" and ansible_distribution_version == "20.04"

tasks:
  - name: Install on Debian or Ubuntu
    apt:
      name: nginx
      state: present
    when: ansible_distribution == "Debian" or ansible_distribution == "Ubuntu"

  # Hoặc dùng list
  - name: Install on Debian family
    apt:
      name: nginx
      state: present
    when: ansible_distribution in ["Debian", "Ubuntu"]

tasks:
  - name: Check if nginx is installed
    command: which nginx
    register: nginx_check
    ignore_errors: yes

  - name: Install nginx if not present
    apt:
      name: nginx
      state: present
    when: nginx_check.rc != 0

  - name: Check disk usage
    shell: df -h / | awk 'NR==2 {print $5}' | sed 's/%//'
    register: disk_usage

  - name: Warning if disk > 80%
    debug:
      msg: "WARNING: Disk usage is {{ disk_usage.stdout }}%"
    when: disk_usage.stdout|int > 80

tasks:
  - name: Install specific version on old Ubuntu
    apt:
      name: nginx=1.18.0-0ubuntu1
      state: present
    when:
      - ansible_distribution == "Ubuntu"
      - ansible_distribution_major_version|int < 22

  - name: Set timezone on physical machines
    timezone:
      name: Asia/Ho_Chi_Minh
    when: ansible_virtualization_role != "guest"

tasks:
  - name: Check if config exists
    stat:
      path: /etc/nginx/nginx.conf
    register: config_file

  - name: Backup config if exists
    copy:
      src: /etc/nginx/nginx.conf
      dest: /etc/nginx/nginx.conf.backup
      remote_src: yes
    when: config_file.stat.exists

  - name: Create config if not exists
    copy:
      src: templates/nginx.conf
      dest: /etc/nginx/nginx.conf
    when: not config_file.stat.exists

vars:
  install_monitoring: true
  enable_ssl: false

tasks:
  - name: Install monitoring agent
    apt:
      name: node-exporter
      state: present
    when: install_monitoring

  - name: Configure SSL
    template:
      src: ssl.conf.j2
      dest: /etc/nginx/ssl.conf
    when: enable_ssl | bool

- name: Install multiple packages
  apt:
    name: "{{ item }}"
    state: present
  loop:
    - nginx
    - git
    - vim
    - htop
    - curl

- name: Create multiple users
  user:
    name: "{{ item.name }}"
    state: present
    groups: "{{ item.groups }}"
    shell: "{{ item.shell }}"
  loop:
    - { name: 'john', groups: 'developers', shell: '/bin/bash' }
    - { name: 'jane', groups: 'admins', shell: '/bin/bash' }
    - { name: 'bob', groups: 'developers', shell: '/bin/zsh' }

- name: Create directories with permissions
  file:
    path: "{{ item.path }}"
    state: directory
    owner: "{{ item.owner }}"
    mode: "{{ item.mode }}"
  loop:
    - { path: '/opt/app', owner: 'appuser', mode: '0755' }
    - { path: '/var/log/app', owner: 'appuser', mode: '0755' }
    - { path: '/etc/app', owner: 'root', mode: '0644' }

vars:
  packages:
    - nginx
    - postgresql
    - redis
  
  users:
    - alice
    - bob
    - charlie

tasks:
  - name: Install packages
    apt:
      name: "{{ item }}"
      state: present
    loop: "{{ packages }}"

  - name: Create users
    user:
      name: "{{ item }}"
      state: present
    loop: "{{ users }}"

- name: Install packages only on Ubuntu
  apt:
    name: "{{ item }}"
    state: present
  loop:
    - nginx
    - apache2
    - mysql-server
  when: ansible_distribution == "Ubuntu"

- name: Create users only in production
  user:
    name: "{{ item }}"
    state: present
  loop:
    - produser1
    - produser2
  when: env == "production"

- name: Check multiple services
  systemd:
    name: "{{ item }}"
  register: service_status
  loop:
    - nginx
    - mysql
    - redis

- name: Display service status
  debug:
    msg: "{{ item.item }} is {{ item.status.ActiveState }}"
  loop: "{{ service_status.results }}"

- name: Create files in multiple directories
  file:
    path: "{{ item.0 }}/{{ item.1 }}"
    state: touch
  loop: "{{ directories | product(files) | list }}"
  vars:
    directories:
      - /tmp/dir1
      - /tmp/dir2
    files:
      - file1.txt
      - file2.txt

- name: Install packages with index
  apt:
    name: "{{ item }}"
    state: present
  loop:
    - nginx
    - git
    - vim
  loop_control:
    index_var: idx
    label: "Installing {{ item }}"

- name: Process with pause between iterations
  command: process_item.sh {{ item }}
  loop:
    - item1
    - item2
    - item3
  loop_control:
    pause: 5  # Pause 5 seconds between iterations

- name: Wait for service to be ready
  uri:
    url: http://localhost:8080/health
    status_code: 200
  register: health_check
  until: health_check.status == 200
  retries: 10
  delay: 5  # Wait 5 seconds between retries