利用ansible进行自动化构建etcd集群
上一篇进行了手动安装etcd集群，此篇利用自动化工具ansible为三个节点构建etcd集群
环境：
master：192.168.101.14，node1：192.168.101.15，node2：192.168.101.19
1、首先查看该role（etcd集群）的目录树结构：
[root@master ansible]# tree
.
├── ansible.cfg
├── hosts
├── roles
│ └── etcd
│ ├── files
│ │ ├── etcd
│ │ └── etcdctl
│ ├── handlers
│ ├── meta
│ ├── tasks
│ │ └── main.yaml
│ ├── templates
│ │ └── etcd.service.j2
│ └── vars
└── work_dir
├── install_etcd_cluster.retry
└── install_etcd_cluster.yaml
首先在hosts文件中定义节点：
[root@master ansible]# egrep -v "^#|^$" hosts [etcd_cluster] 192.168.101.14 192.168.101.15 192.168.101.19
在roles目录下面创建了etcd这个角色，角色目录下面为个节点提供了命令文件etcd、etcdctl，然后查看tasks下面的main.yaml：
[root@master ansible]# cat roles/etcd/tasks/main.yaml - name: copy etcd to nodes copy: src: ../files/etcd dest: /usr/local/bin/etcd mode: 0750 - name: copy etcdctl to nodes copy: src: ../files/etcdctl dest: /usr/local/bin/etcdctl mode: 0750 - name: create data directory for etcd file: path: /var/lib/etcd state: directory - name: provide etcd.service to nodes template: src: etcd.service.j2 dest: /usr/lib/systemd/system/etcd.service register: result - name: start etcd service systemd: daemon_reload: true name: etcd state: started enabled: true when: result|success
前面三个任务是copy命令文件到各节点，和在各节点上创建数据目录，在下面的任务中定义了template，首先查看template下面的j2文件：
[root@master ansible]# cat roles/etcd/templates/etcd.service.j2 [Unit] Description=etcd server After=network.target After=network-online.target Wants=network-online.target [Service] Type=notify WorkingDirectory=/var/lib/etcd/ EnvironmentFile=-/etc/etcd/etcd.conf ExecStart=/usr/local/bin/etcd --name {{ ansible_hostname }} --initial-advertise-peer-urls http://{{ ansible_ens33.ipv4.address }}:2380 --listen-peer-urls http://{{ ansible_ens33.ipv4.address }}:2380 --listen-client-urls http://{{ ansible_ens33.ipv4.address }}:2379,http://127.0.0.1:2379 --advertise-client-urls http://{{ ansible_ens33.ipv4.address }}:2379 --initial-cluster-token etcd-cluster-1 --initial-cluster master=http://192.168.101.14:2380,node1=http://192.168.101.15:2380,node2=http://192.168.101.19:2380 --initial-cluster-state new --data-dir=/var/lib/etcd Restart=on-failure RestartSec=5 LimitNOFILE=65536 [Install] WantedBy=multi-user.target
可以看见上面的j2文件里面运用了变量{{ ansible_hostname }}和{{ ansible_ens33.ipv4.address }}，这两个变量可以根据模块setup进行获得（获取各节点的hostname和ip地址）
在运用了template模板下面，在j2文件中定义了变量，于是ansible将该j2文件分发给各节点上，然后各节点根据自己的hostname和ip进行相应修改，于是创建的配置文件与自己的hostname和ip是一一对应的
在配置文件中使用变量可以使用template模块，创建对应的j2文件
[root@master ansible]# cat work_dir/install_etcd_cluster.yaml - hosts: etcd_cluster remote_user: root roles: - etcd
[root@master ansible]# ansible-playbook work_dir/install_etcd_cluster.yaml PLAY [etcd_cluster] *********************************************************************************************************************************** TASK [Gathering Facts] ******************************************************************************************************************************** ok: [192.168.101.19] ok: [192.168.101.14] ok: [192.168.101.15] TASK [etcd : copy etcd to nodes] ********************************************************************************************************************* ok: [192.168.101.15] ok: [192.168.101.19] ok: [192.168.101.14] TASK [etcd : copy etcdctl to nodes] ******************************************************************************************************************* ok: [192.168.101.15] ok: [192.168.101.19] ok: [192.168.101.14] TASK [etcd : create data directory for etcd] ********************************************************************************************************** ok: [192.168.101.15] ok: [192.168.101.19] ok: [192.168.101.14] TASK [etcd : provide etcd.service to nodes] *********************************************************************************************************** ok: [192.168.101.19] ok: [192.168.101.15] ok: [192.168.101.14] TASK [etcd : start etcd service] ********************************************************************************************************************** changed: [192.168.101.15] changed: [192.168.101.19] changed: [192.168.101.14] PLAY RECAP ******************************************************************************************************************************************** 192.168.101.14 : ok=6 changed=1 unreachable=0 failed=0 192.168.101.15 : ok=6 changed=1 unreachable=0 failed=0 192.168.101.19 : ok=6 changed=1 unreachable=0 failed=0
执行完成后，在任意节点上查看member列表：
[root@master ~]# etcdctl member list 192d36c71643c39d: name=node2 peerURLs=http://192.168.101.19:2380 clientURLs=http://192.168.101.19:2379 isLeader=false 5f3835545a5f41e4: name=master peerURLs=http://192.168.101.14:2380 clientURLs=http://192.168.101.14:2379 isLeader=false 77c1ac60c5100363: name=node1 peerURLs=http://192.168.101.15:2380 clientURLs=http://192.168.101.15:2379 isLeader=true
验证集群的监控状态：
[root@master ~]# etcdctl cluster-health member 192d36c71643c39d is healthy: got healthy result from http://192.168.101.19:2379 member 5f3835545a5f41e4 is healthy: got healthy result from http://192.168.101.14:2379 member 77c1ac60c5100363 is healthy: got healthy result from http://192.168.101.15:2379 cluster is healthy
于是etcd集群基于ansible的无TSL认证的搭建成功完成
附上当配置文件change之后触发handler：
[root@master ansible]# cat roles/etcd/handlers/main.yaml - name: restart etcd systemd: name: etcd state: restarted
[root@master ansible]# cat roles/etcd/tasks/main.yaml - name: copy etcd to nodes copy: src: ../files/etcd dest: /usr/local/bin/etcd mode: 0750 - name: copy etcdctl to nodes copy: src: ../files/etcdctl dest: /usr/local/bin/etcdctl mode: 0750 - name: create data directory for etcd file: path: /var/lib/etcd state: directory - name: provide etcd.service to nodes template: src: etcd.service.j2 dest: /usr/lib/systemd/system/etcd.service register: result - name: start etcd service systemd: daemon_reload: true name: etcd state: started enabled: true when: result|success - name: provide configfile changed to etcd template: src: etcd.service_https_auto.j2 dest: /usr/lib/systemd/system/etcd.service notify: restart etcd
改变后的配置文件：
[root@master ansible]# cat roles/etcd/templates/etcd.service_https_auto.j2 [Unit] Description=etcd server After=network.target After=network-online.target Wants=network-online.target [Service] Type=notify WorkingDirectory=/var/lib/etcd/ EnvironmentFile=-/etc/etcd/etcd.conf ExecStart=/usr/local/bin/etcd --name {{ ansible_hostname }} --auto-tls --peer-auto-tls --initial-advertise-peer-urls https://{{ ansible_ens33.ipv4.address }}:2380 --listen-peer-urls https://{{ ansible_ens33.ipv4.address }}:2380 --listen-client-urls https://{{ ansible_ens33.ipv4.address }}:2379,https://127.0.0.1:2379 --advertise-client-urls https://{{ ansible_ens33.ipv4.address }}:2379 --initial-cluster-token etcd-cluster-1 --initial-cluster master=https://192.168.101.14:2380,node1=https://192.168.101.15:2380,node2=https://192.168.101.19:2380 --initial-cluster-state new --data-dir=/var/lib/etcd Restart=on-failure RestartSec=5 LimitNOFILE=65536 [Install] WantedBy=multi-user.target
