Ansible 安裝 Redis Replication 更新版

之前筆記 使用 Ansible 安裝 Redis Replication 中紀錄使用 Ansible 來安裝 Redis Replication，但畢竟是 Ansible 新手，很多好用的 function 都沒真的用上，多數都是土法鍊鋼用 script 硬上的，經過一段時間的練習，來更新一下自己覺得比較好的寫法，做為比較紀錄

基本環境說明

1. Azure VM B2s (2 vcpu,4GiB memory)
2. CentOS-based 7.7
3. Redis 5.0.7
4. epel-release.noarch 0:7-11
5. ius-release.noarch 0:2-1.el7.ius
6. ansible 2.9.10
7. python 2.7.15

安裝語法

1. 專案結構

   • roles
     • redis-replication
       • handlers
         • main.yml
       • tasks
         • checkdir.yml
         • installredis.yml
         • installtools.yml
         • main.yml
         • prepareservice.yml
         • prepareredisconfig.yml
         • preparesentinelconfig.yml
         • uninstall.yml
         • upgrade.yml
       • templates
         • config.j2
         • sentinel.j2
         • service.j2
       • vars
         • main.yml
       • inventories
         • dev.ini
       • README.md
   • ansible.cfg
   • main.yml

2. 完整內容

   • roles

     • redis-replication

       • handlers

         • main.yml

           ---
           - name: "Restart Redis Service"
           listen: restart-service
           systemd:
             name: "redis_{{redis_port}}"
             daemon_reload: yes
             enabled: yes
             state: restarted
           

       • tasks

         • checkdir.yml

           ---
           - name: Ensures dir exists
           file:
             path: "{{ item.folder }}"
             state: directory
             mode: 0755
             owner: redis
             recurse: yes
           

         • installredis.yml

           ---
           - name: Install Redis
           yum:
             name: "{{redisversion}}"
             state: latest
           

         • installtools.yml

           - name: Install IUS
           yum:
             name:
               - https://repo.ius.io/ius-release-el7.rpm
               - https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
             state: latest
                             
           - include_tasks: installredis.yml
                             
           - include_tasks: checkdir.yml
           with_items:
           - {folder: "/etc/redis"}
                             
           - name: Remove default redis service
           shell: |
             systemctl disable redis
                             
           - name: Delete redis service
           file: 
             path: "{{ item }}"
             state: absent
           with_items: 
             - /usr/lib/systemd/system/redis.service
             - /etc/systemd/system/redis.service.d
             - /etc/systemd/system/redis-sentinel.service.d
                             
           - name: Disable SELinux
           shell: |
             setenforce 0
             sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
                             
           - name: Allow Overcommit Memory
           sysctl:
             name: vm.overcommit_memory
             value: "1"
             state: present
             reload: yes
             ignoreerrors: yes
                             
           - name: Stop and disable firewalld.
           service:
             name: firewalld
             state: stopped
             enabled: False
           

         • main.yml

           ---
           - include_tasks: uninstall.yml
           when: action == 'uninstall' or action == 'reinstall'
                             
           - include_tasks: installtools.yml
           when: action == 'install'
                             
           - include_tasks: upgrade.yml
           when: action == 'upgrade'
                             
           - include_tasks: prepareservice.yml
           when: action == 'install' or action == 'reinstall'
                             
           - include_tasks: prepareredisconfig.yml
           when: action != 'uninstall'
                             
           - include_tasks: preparesentinelconfig.yml
           when: action != 'uninstall'
           

         • prepareservice.yml

           ---
           - name: Prepare services
           template:
             src: service.j2
             dest: "/etc/systemd/system/redis_{{redis_port}}.service"
             owner: redis
           

         • prepareredisconfig.yml

           ---
           - include_tasks: checkdir.yml
           with_items: 
           - {folder: "/etc/redis/redis_{{ redis_port }}"}
                             
           - name: Prepare Master Configs
           template:
             src: config.j2
             dest: "/etc/redis/redis_{{ redis_port }}.conf"
             owner: redis
           when: redis_role == "master" or redis_role == "slave"
           notify: restart-service
           

         • preparesentinelconfig.yml

           ---
           - include_tasks: checkdir.yml
           with_items: 
           - {folder: "/etc/redis"}
                             
           - name: Prepare Sentinel Configs
           template:
             src: sentinel.j2
             dest: "/etc/redis/redis_{{redis_port}}.conf"
             owner: redis
           when: redis_role == "sentinel"
           notify: restart-service
           

         • uninstall.yml

           - name: Stop Service
           service:
             name: "redis_{{redis_port}}"
             state: stopped
                             
           - name: Disable Service
           shell: |
             systemctl disable redis_{{redis_port}}
                             
           - name: Delete config
           file:
             path: "{{ item }}"
             state: absent
           with_items:
             - /etc/redis/redis_{{redis_port}}.conf
             - /etc/systemd/system/redis_{{redis_port}}.service
           
           

         • upgrade.yml

           ---
           - include_tasks: installredis.yml
           

       • templates

         • config.j2

           dir /etc/redis/redis_{{redis_port}}
           bind {{redis_ip}} 127.0.0.1
           requirepass {{redispass}}
           {% if redis_role == "slave" and master_target is defined %}
           replicaof {{hostvars[master_target]['redis_ip']}} {{hostvars[master_target]['redis_port']                    }}
           {% endif %}
           masterauth {{redispass}}
           port {{redis_port}}
           pidfile /var/run/redis_{{redis_port}}.pid
           maxclients 100000
           maxmemory-policy volatile-lru
           loglevel notice
           

         • sentinel.j2

           bind {{redis_ip}}
           port {{redis_port}}
                               
           {% for master in groups['redis_masters'] %}
           dir /etc/redis/redis_{{redis_port}}
                               
           sentinel monitor master_{{ loop.index }} {{hostvars[master]['redis_ip']}} {{hostvars [master]['redis_port']}} {{ 1 if groups['redis_sentinels']|length < 2 else (groups                    ['redis_sentinels']|length)-2 }}
           sentinel auth-pass master_{{ loop.index }} {{redispass}}
           sentinel down-after-milliseconds master_{{ loop.index }}  3000
           sentinel parallel-syncs master_{{ loop.index }}  1
           sentinel failover-timeout master_{{ loop.index }}  18000
           {% endfor %}
           

         • service.j2

           [Unit]
           Description=Redis persistent key-value database
           After=network.target
           After=network-online.target
           Wants=network-online.target
                               
           [Service]
           {% if redis_role == 'sentinel' %}
           ExecStart=/usr/bin/redis-sentinel /etc/redis/redis_{{redis_port}}.conf --supervised                     systemd
           {% else %}
           ExecStart=/usr/bin/redis-server /etc/redis/redis_{{redis_port}}.conf --supervised systemd
           {% endif %}
                               
           ExecStop=/usr/libexec/redis-shutdown
           Type=notify
           User=redis
           Group=redis
           RuntimeDirectory=redis_{{redis_port}}
           RuntimeDirectoryMode=0755
                               
           [Install]
           WantedBy=multi-user.target
           

       • vars

         • main.yml

           action: update
           redispass: pass.123
           redisversion: redis5-5.0.7-1.el7.ius
           

       • inventories

         • dev.ini

           [redis_instances]
           redis1 ansible_host=192.168.50.51 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123
           redis2 ansible_host=192.168.50.51 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123
           redis_sentinel_1 ansible_host=192.168.50.51 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123
           redis_sentinel_2 ansible_host=192.168.50.51 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123
           redis_sentinel_3 ansible_host=192.168.50.51 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123
           
           [redis_masters]
           redis1 redis_port=6379 redis_role=master
           
           [redis_slaves]
           redis2 redis_port=6380 redis_role=slave master_target=redis1
           
           [redis_sentinels]
           redis_sentinel_1 redis_port=26379 redis_role=sentinel
           redis_sentinel_2 redis_port=26380 redis_role=sentinel
           redis_sentinel_3 redis_port=26381 redis_role=sentinel
           
           [redis_all:children]
           redis_masters
           redis_slaves
           redis_sentinels
           

       • README.md

         ## 全新安裝
         
             ```bash
             ansible-playbook -i roles/redis-replication/inventories/dev.ini -e "action=install" main.yml
             ```
         
         ## 重新安裝
         
             > 先 uninstall 並排除安裝基本套件
         
             ```bash
             ansible-playbook -i roles/redis-replication/inventories/dev.ini -e                 "action=reinstall" main.yml
             ```
         
         ## 更新 config
         
             ```bash
             ansible-playbook -i roles/redis-replication/inventories/dev.ini main.yml
             ```
         
         ## 升級
         
             ```
             ansible-playbook -i roles/redis-replication/inventories/dev.ini -e "action=upgrade" main.yml
             ```
                         
         ## restart service
         
             ```
             ansible-playbook -i roles/redis-replication/inventories/dev.ini -e "action=restart" main.yml
             ```
         

   • ansible.cfg

     [ironman]
     roles_path = ./roles
     
     [defaults]
     host_key_checking = False
     

   • main.yml

     - hosts: redis_all
     roles:
       - redis-replication
     

心得

完整程式碼請參考 ansible-redis-replication

大致流程與之前筆記 使用 Ansible 安裝 Redis Replication 相去不遠，只是改用 ansible 的 function 來處理

另外比較大的變化是使用 ansible role 的功能來管理，讓 ansible 的 script 可以擁有較高的共用性

參考資訊

1. 使用 Ansible 安裝 Redis Replication
2. ansible-redis-replication