如何在ansible中为不同的主机在另一个任务中使用一个任务的return值

Question

我正在尝试为由 2 个 mysql 主机组成的主机组设置 mysql 主从复制和 ansible。

这是我的场景：

我运行在第一个主机中执行一个任务并跳过第二个主机，所以第一个任务（即主复制状态）returns一些值，如位置、文件等

然后，我运行第二台主机中的另一个任务（跳过第一台主机），该任务使用第一台任务的 return 值，如 master.Position、master.File等

现在，当我运行剧本时，第一个任务的变量似乎在第二个任务中不起作用

库存文件

    [mysql]
    stagmysql01 ansible_host=1.1.1.1 ansible_ssh_user=ansible ansible_connection=ssh
    stagmysql02 ansible_host=1.1.1.2 ansible_ssh_user=ansible ansible_connection=ssh

Master 上的任务

- name: Mysql - Check master replication status.
  mysql_replication: mode=getmaster
  register: master

- debug: var=master

Slave 上的任务

- name: Mysql - Configure replication on the slave.
  mysql_replication:
    mode: changemaster
    master_host: "{{ replication_master }}"
    master_user: "{{ replication_user }}"
    master_password: "{{ replication_pass }}"
    master_log_file: "{{ master.File }}"
    master_log_pos: "{{ master.Position }}"
  ignore_errors: True

主输出

TASK [Mysql_Base : Mysql - Check master replication status.] ****************
skipping: [stagmysql02]
ok: [stagmysql01]

TASK [Mysql_Base : debug] ***************************************************
ok: [stagmysql01] => {
    "master": {
        "Binlog_Do_DB": "", 
        "Binlog_Ignore_DB": "mysql,performance_schema", 
        "Executed_Gtid_Set": "", 
        "File": "mysql-bin.000003", 
        "Is_Master": true, 
        "Position": 64687163, 
        "changed": false, 
        "failed": false
    }
}
ok: [stagmysql02] => {
    "master": {
        "changed": false, 
        "skip_reason": "Conditional result was False", 
        "skipped": true
    }
}

从机输出

TASK [Mysql_Base : Mysql - Configure replication on the slave.] *************
skipping: [stagmysql01]
fatal: [stagmysql02]: FAILED! => {"failed": true, "msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'File'\n\nThe error appears to have been in '/root/ansible/roles/Mysql_Base/tasks/replication.yml': line 30, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Mysql - Configure replication on the slave.\n  ^ here\n\nexception type: <class 'ansible.errors.AnsibleUndefinedVariable'>\nexception: 'dict object' has no attribute 'File'"}
...ignoring

正如您在上面看到的那样，由于未定义的变量，第二个主机的第二个任务失败了。但是，第一台主机的第一项任务中存在所需的变量。

如何在另一个任务中使用从第 1 台主机到第 2 台主机的变量 return？

P.S：我看到了使用{{ hostvars[[=52=]]['variable'] }}的方法。但是我对这种方法很困惑，因为需要直接添加 inventory_hostname 或 IP 地址。我一直在寻找可用于不同库存文件和剧本的通用模板。

Answer 1

我能够通过将变量定义为新的 虚拟主机 然后在整个剧本中使用它来解决我的问题 hostvars .

How do I set register a variable to persist between plays in ansible?中的一个答案中已经提到了类似的解决方案但是直到我发布这个问题我才注意到它。

这是我在 ansible 任务中所做的：

我创建了一个虚拟主机 master_value_holder 并定义了所需的变量。（这里我需要 master_log_file 和 master_log_Postion)
使用 hostvars[[=52=]]['master_log_file']

Master 上的任务

- name: Mysql - Check master replication status.
  mysql_replication: mode=getmaster
  register: master

- name: "Add master return values to a dummy host"
  add_host:
    name:   "master_value_holder"
    master_log_file: "{{ master.File }}"
    master_log_pos: "{{ master.Position }}"

从属任务

- name: Mysql - Displaying master replication status
  debug: msg="Master Bin Log File  is {{ hostvars['master_value_holder']['master_log_file'] }} and Master Bin Log Position is {{ hostvars['master_value_holder']['master_log_pos'] }}"

- name: Mysql - Configure replication on the slave.
  mysql_replication:
    mode: changemaster
    master_host: "{{ replication_master }}"
    master_user: "{{ replication_user }}"
    master_password: "{{ replication_pass }}"
    master_log_file: "{{ hostvars['master_value_holder']['master_log_file'] }}"
    master_log_pos: "{{ hostvars['master_value_holder']['master_log_pos'] }}"
  when: ansible_eth0.ipv4.address != replication_master and not slave.Slave_SQL_Running

输出

TASK [Mysql_Base : Mysql - Check master replication status.] ****************
skipping: [stagmysql02]
ok: [stagmysql01]

TASK [AZ-Mysql_Base : Add master return values to a dummy host] ****************
changed: [stagmysql01]

TASK [AZ-Mysql_Base : Mysql - Displaying master replication status] ************
ok: [stagmysql01] => {
    "msg": "Master Bin Log File  is mysql-bin.000001 and Master Bin Log Position is 154"
}
ok: [stagmysql02] => {
    "msg": "Master Bin Log File  is mysql-bin.000001 and Master Bin Log Position is 154"
}

TASK [AZ-Mysql_Base : Mysql - Configure replication on the slave.] *************
skipping: [stagmysql01]
skipping: [stagmysql02]

从上面的输出可以看出，主复制状态现在可用于两台主机。

如何在ansible中为不同的主机在另一个任务中使用一个任务的return值

How to use return values of one task in another task for a different host in ansible

mysql

ansible

ansible-2.x

ansible-facts