Ansible 安裝 Redis Cluster

已有更新版，請參考 Ansible 安裝 Redis Cluster (更新版)

之前筆記 Ansible 安裝 Redis Replication 更新版 紀錄了以 ansible 內建 function 為主的 redis replication 安裝 script，順手紀錄一下 redis cluster 的安裝方式

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-cluster
        • handlers
          • main.yml
        • tasks
          • checkdir.yml
          • createcluster.yml
          • installredis.yml
          • installtools.yml
          • main.yml
          • prepareservice.yml
          • prepareredisconfig.yml
          • uninstall.yml
          • upgrade.yml
        • templates
          • config.j2
          • service.j2
        • vars
          • main.yml
        • inventories
          • dev.ini
        • README.md
    • ansible.cfg
    • main.yml

  2. 完整內容

    • roles

      • redis-cluster

        • 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

          • createcluster.yml

            ---
- name: Create Cluster debug
debug:
  msg: redis-cli -a {{redispass}} --cluster-replicas 1 --cluster create {% for redis_node in groups['redis_all'] %}{{ hostvars[redis_node]['redis_ip'] }}:{{ hostvars[redis_node]['redis_port'] }} {% endfor %}

- name: Create Cluster
shell: |
  echo "yes" |redis-cli -a {{redispass}} --cluster-replicas 1 --cluster create {% for redis_node in groups['redis_all'] %}{{ hostvars[redis_node]['redis_ip'] }}:{{ hostvars[redis_node]['redis_port'] }} {% endfor %}

          • 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'
                  
- name: Restart Service
debug:
  msg: restart service
notify: restart-service
changed_when: true
when: action == 'restart'
                  
- meta: flush_handlers
                  
- include_tasks: createcluster.yml
run_once: true
when: action == 'install' or action == 'reinstall'

          • 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
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}}
masterauth {{redispass}}
port {{redis_port}}
pidfile /var/run/redis_{{redis_port}}.pid
maxclients 100000
# 啟用 redis cluster
cluster-enabled yes
# 每個 node 需要獨立，cluster 自行維護使用，不需人為介入
cluster-config-file nodes_{{redis_port}}.conf
# node 判斷失效的時間
cluster-node-timeout 5000
maxmemory-policy volatile-lru
loglevel notice

          • service.j2

            [Unit]
Description=Redis persistent key-value database
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
ExecStart=/usr/bin/redis-server /etc/redis/redis_{{redis_port}}.conf --supervisedsystemd

ExecStop=/usr/libexec/redis-shutdown  redis_{{redis_port}}
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_all]
redis1 ansible_host=127.0.0.1 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123 redis_port=7000
redis2 ansible_host=127.0.0.1 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123 redis_port=7001
redis3 ansible_host=127.0.0.1 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123 redis_port=7002
redis4 ansible_host=127.0.0.1 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123 redis_port=7003
redis5 ansible_host=127.0.0.1 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123 redis_port=7004
redis6 ansible_host=127.0.0.1 redis_ip=10.0.1.5 ansible_ssh_user=root ansible_ssh_pass=pass.123 redis_port=7005

        • 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-cluster

心得

完整程式碼請參考 ansible-redis-cluster

安裝方式跟 redis-replication 一樣，而流程甚至更簡單：不用自行管理 master、slave 與 sentinel，不過中間還是有些需要注意的重點

  1. 建立 cluster 前需要確保所有 redis service 都已啟動 (flush_handlers)
  2. 另外是 cluster 的建立行為只需要執行一次 (run_once: true)

已有更新版，請參考 Ansible 安裝 Redis Cluster (更新版)

參考資訊

  1. Ansible 安裝 Redis Replication 更新版
  2. ansible-redis-cluster