11.8. 使用资源限制配置高可用性集群

步骤

1. 创建包含以下内容的 playbook 文件，如 ~/playbook.yml ：

   ---
   - name: Create a high availability cluster with resource constraints
     hosts: node1 node2
     roles:
       - rhel-system-roles.ha_cluster
     vars:
       ha_cluster_cluster_name: my-new-cluster
       ha_cluster_hacluster_password: <password>
       ha_cluster_manage_firewall: true
       ha_cluster_manage_selinux: true
       # In order to use constraints, we need resources the constraints will apply
       # to.
       ha_cluster_resource_primitives:
         - id: xvm-fencing
           agent: 'stonith:fence_xvm'
           instance_attrs:
             - attrs:
                 - name: pcmk_host_list
                   value: node1 node2
         - id: dummy-1
           agent: 'ocf:pacemaker:Dummy'
         - id: dummy-2
           agent: 'ocf:pacemaker:Dummy'
         - id: dummy-3
           agent: 'ocf:pacemaker:Dummy'
         - id: dummy-4
           agent: 'ocf:pacemaker:Dummy'
         - id: dummy-5
           agent: 'ocf:pacemaker:Dummy'
         - id: dummy-6
           agent: 'ocf:pacemaker:Dummy'
       # location constraints
       ha_cluster_constraints_location:
         # resource ID and node name
         - resource:
             id: dummy-1
           node: node1
           options:
             - name: score
               value: 20
         # resource pattern and node name
         - resource:
             pattern: dummy-\d+
           node: node1
           options:
             - name: score
               value: 10
         # resource ID and rule
         - resource:
             id: dummy-2
           rule: '#uname eq node2 and date in_range 2022-01-01 to 2022-02-28'
         # resource pattern and rule
         - resource:
             pattern: dummy-\d+
           rule: node-type eq weekend and date-spec weekdays=6-7
       # colocation constraints
       ha_cluster_constraints_colocation:
         # simple constraint
         - resource_leader:
             id: dummy-3
           resource_follower:
             id: dummy-4
           options:
             - name: score
               value: -5
         # set constraint
         - resource_sets:
             - resource_ids:
                 - dummy-1
                 - dummy-2
             - resource_ids:
                 - dummy-5
                 - dummy-6
               options:
                 - name: sequential
                   value: "false"
           options:
             - name: score
               value: 20
       # order constraints
       ha_cluster_constraints_order:
         # simple constraint
         - resource_first:
             id: dummy-1
           resource_then:
             id: dummy-6
           options:
             - name: symmetrical
               value: "false"
         # set constraint
         - resource_sets:
             - resource_ids:
                 - dummy-1
                 - dummy-2
               options:
                 - name: require-all
                   value: "false"
                 - name: sequential
                   value: "false"
             - resource_ids:
                 - dummy-3
             - resource_ids:
                 - dummy-4
                 - dummy-5
               options:
                 - name: sequential
                   value: "false"
       # ticket constraints
       ha_cluster_constraints_ticket:
         # simple constraint
         - resource:
             id: dummy-1
           ticket: ticket1
           options:
             - name: loss-policy
               value: stop
         # set constraint
         - resource_sets:
             - resource_ids:
                 - dummy-3
                 - dummy-4
                 - dummy-5
           ticket: ticket2
           options:
             - name: loss-policy
               value: fence

   这个示例 playbook 文件配置一个运行 firewalld 和 selinux 服务的集群。集群包括资源位置约束、资源托管约束、资源顺序约束和资源票据约束。

   为生产环境创建 playbook 文件时，vault 会加密密码，如在 使用 Ansible Vault 加密内容 中所述。

2. 验证 playbook 语法：

   $ ansible-playbook --syntax-check ~/playbook.yml

   请注意，这个命令只验证语法，不会防止错误但有效的配置。

3. 运行 playbook：

   $ ansible-playbook ~/playbook.yml