Ansible：如何获取列表（stdout_lines）的值？

Question

感谢您给我一些时间阅读这个问题。 :)

我完整的剧本是：

---

- hosts: all
  remote_user: secret_user
  become: yes

  tasks:

    - include_vars: vars.yml

    - name: Copy set of rpms/binaries/and Java scripts to server.
      copy:
        src: "{{ item }}"
        dest: "{{ tempdir }}"
      with_items:
        - files/mongo-10gen-2.4.4-5.el6.x86_64.rpm
        - files/mongo-10gen-server-2.4.4-5.el6.x86_64.rpm
        - files/mongo-10gen-2.6-1.el6.x86_64.rpm
        - files/mongo-10gen-server-2.6-1.el6.x86_64.rpm
        - files/mongo26
        - bash/javascript/populateDB.js

    - name: Create mongo user.
      user:
        name: mongod
        comment: For mongo installation.
        home: /var/lib/mongo
        shell: /bin/false

    - name: Install mongo-2.4
      yum:
        name: "{{ item }}"
        state: present
      with_items:
        - "{{ tempdir }}/mongo-10gen-2.4.4-5.el6.x86_64.rpm"
        - "{{ tempdir }}/mongo-10gen-server-2.4.4-5.el6.x86_64.rpm"

    - name: Send configuration files.
      template:
        src: "{{ item.src }}"
        dest: "{{ item.dest }}"
      with_items:
              - { src: 'templates/mongod.j2', dest: '/etc/mongod.conf' }
              - { src: 'templates/mongodb-configsvr.j2', dest: '/etc/mongodb-configsvr.conf' }

    - name: Create directories to storing logs.
      file:
        path: "{{ item }}"
        state: directory
        owner: mongod
        group: mongod
        mode: u=rwx,g=rw,o=rw
        recurse: yes
      with_items:
        - /var/log/mongodb/
        - /var/lib/mongodb/
        - /var/lib/mongodb-config/

    - name: Create files to storing logs.
      file:
        path: "{{ item }}"
        state: touch
        owner: mongod
        group: mongod
      with_items:
        - /var/log/mongodb/mongod.log

    - name: Start mongo2.4 service
      shell: "{{ item }}"
      with_items:
        - /usr/bin/mongod -f /etc/mongod.conf
        - /usr/bin/mongod -f /etc/mongodb-configsvr.conf
      ### Remove or comment once test is finished.
      ignore_errors: yes

      #name: mongod
      # state: started
      #  args: -f /etc/mongod.conf

      #### Finished Pre tasks

    - name: Check who is the master.
      script:
        cmd: bash/checkmaster.sh
        chdir: "{{ tempdir }}"
      register: master
      when: inventory_hostname == play_hosts[0]

    - name: Check who are the secondary nodes.
      script:
        cmd: bash/checksecond.sh
        chdir: "{{ tempdir }}"
      register: secondary
      when: inventory_hostname == play_hosts[0]

    - name: debug var name.
      debug:
        var: master

    - name: debug var name - second.
      debug:
        var: secondary

    - name: Populate DB. (Execute only if is a NEW INSTALLATION).
      script:
        cmd: bash/populateDB.sh
        chdir: "{{ tempdir }}"
      register: populateDB
      with_items:
        - "{{ master.stdout_lines }}"

    - name: (Before upgrade.) Execute V2.6 script to validate if is good to proceed.
      script: 
        cmd: bash/mongo2.6.sh
        chdir: "{{ tempdir }}"
      register: Mongo26
      failed_when:
        - '"Everything is ready for the upgrade!" not in Mongo26.stdout'
      with_items:
        - "{{ master.stdout_lines }}"

      # Starting with upgrade.

    - name: Upgrading on SECONDARY NODES - Stop and installing service node:1.
      shell: pgrep mongo | xargs kill -2; rpm -Uvh "{{ tempdir }}/mongo-10gen-2.6-1.el6.x86_64.rpm"; rpm -Uvh "{{ tempdir }}/mongo-10gen-server-2.6-1.el6.x86_64.rpm"
      throttle: 1
      with_items:
        - "{{ secondary.stdout_lines[0] }}"
        - "{{ secondary.stdout_lines[1] }}"

我的问题是最后一个名为Upgrading on secondary nodes的任务。 我想要实现的是获取列表secondary.stdoutlines的值，以便仅将最后一个任务传递给这些服务器。 这个变量的内容有：

TASK [debug var name - second.] ****************************************************************************************************************************************************************************
ok: [192.168.33.2] => {
    "secondary": {
        "changed": true,
        "failed": false,
        "rc": 0,
        "stderr": "Shared connection to 192.168.33.2 closed.\r\n",
        "stderr_lines": [
            "Shared connection to 192.168.33.2 closed."
        ],
        "stdout": "\r\nmongodb02.ppc.us\r\nmongodb03.ppc.us\r\n",
        "stdout_lines": [
            "",
            "mongodb02.ppc.us",
            "mongodb03.ppc.us"
        ]
    }
}
ok: [192.168.33.3] => {
    "secondary": {
        "changed": false,
        "skip_reason": "Conditional result was False",
        "skipped": true
    }
}
ok: [192.168.33.4] => {
    "secondary": {
        "changed": false,
        "skip_reason": "Conditional result was False",
        "skipped": true
    }
}

所以，我试图在{{secondary.stdout_lines}}上列出的节点上运行最后一个任务。 每次我运行剧本时，都会：

      with_items:
        - "{{ secondary.stdout_lines[0] }}"
        - "{{ secondary.stdout_lines[1] }}"

此任务在第一个节点 (mongodb01) 上执行，而不是在 secondary.stdout_lines (mongodb02, mongodb03) 中执行。

有没有人知道如何实现这一目标？

提前致谢！

编辑：这是新问题：

inventory:

---
all:
  hosts:
    mongodb01.ppc.us:
      ansible_host: 192.168.33.2
    mongodb02.ppc.us:
      ansible_host: 192.168.33.3
    mongodb03.ppc.us:
      ansible_host: 192.168.33.4
  vars:
    ansible_python_interpreter: /usr/bin/python

调试任务：

• 变量：主

TASK [debug] ***********************************************************************************************************************************************************************************************
ok: [mongodb01.ppc.us] => {
    "master": {
        "changed": true,
        "failed": false,
        "rc": 0,
        "stderr": "Shared connection to mongodb01.ppc.us closed.\r\n",
        "stderr_lines": [
            "Shared connection to mongodb01.ppc.us closed."
        ],
        "stdout": "\r\nmongodb01.ppc.us\r\n",
        "stdout_lines": [
            "",
            "mongodb01.ppc.us"
        ]
    }
}
ok: [mongodb02.ppc.us] => {
    "master": {
        "changed": true,
        "failed": false,
        "rc": 0,
        "stderr": "Shared connection to mongodb02.ppc.us closed.\r\n",
        "stderr_lines": [
            "Shared connection to mongodb02.ppc.us closed."
        ],
        "stdout": "\r\nmongodb01.ppc.us\r\n",
        "stdout_lines": [
            "",
            "mongodb01.ppc.us"
        ]
    }
}
ok: [mongodb03.ppc.us] => {
    "master": {
        "changed": true,
        "failed": false,
        "rc": 0,
        "stderr": "Shared connection to mongodb03.ppc.us closed.\r\n",
        "stderr_lines": [
            "Shared connection to mongodb03.ppc.us closed."
        ],
        "stdout": "\r\nmongodb01.ppc.us\r\n",
        "stdout_lines": [
            "",
            "mongodb01.ppc.us"
        ]
    }
}

• inventory_hostname 的调试

TASK [debug] ***********************************************************************************************************************************************************************************************
ok: [mongodb01.ppc.us] => {
    "inventory_hostname": "mongodb01.ppc.us"
}
ok: [mongodb02.ppc.us] => {
    "inventory_hostname": "mongodb02.ppc.us"
}
ok: [mongodb03.ppc.us] => {
    "inventory_hostname": "mongodb03.ppc.us"
}
[WARNING]: Could not match supplied host pattern, ignoring: role_master

PLAY [role_master] *****************************************************************************************************************************************************************************************
skipping: no hosts matched

PLAY [role_secondary] **************************************************************************************************************************************************************************************

• 检查主节点任务：

TASK [check master node] ***********************************************************************************************************************************************************************************
changed: [mongodb01.ppc.us] => {"changed": true, "rc": 0, "stderr": "Shared connection to 192.168.33.2 closed.\r\n", "stderr_lines": ["Shared connection to 192.168.33.2 closed."], "stdout": "\r\nmongodb01.ppc.us\r\n", "stdout_lines": ["", "mongodb01.ppc.us"]}
changed: [mongodb02.ppc.us] => {"changed": true, "rc": 0, "stderr": "Shared connection to 192.168.33.3 closed.\r\n", "stderr_lines": ["Shared connection to 192.168.33.3 closed."], "stdout": "\r\nmongodb01.ppc.us\r\n", "stdout_lines": ["", "mongodb01.ppc.us"]}
changed: [mongodb03.ppc.us] => {"changed": true, "rc": 0, "stderr": "Shared connection to 192.168.33.4 closed.\r\n", "stderr_lines": ["Shared connection to 192.168.33.4 closed."], "stdout": "\r\nmongodb01.ppc.us\r\n", "stdout_lines": ["", "mongodb01.ppc.us"]}

Answer 1

首先，让我们看看你的问题。

在您的游戏中的第一个主机（ play_hosts[0] ）上，您将secondary变量设置为运行bash/checksecond.sh的结果。 您明确没有在剧中的任何其他主机上执行此操作。 这意味着当您运行此任务时...

    - name: Upgrading on SECONDARY NODES - Stop and installing service node:1.
      shell: pgrep mongo | xargs kill -2; rpm -Uvh "{{ tempdir }}/mongo-10gen-2.6-1.el6.x86_64.rpm"; rpm -Uvh "{{ tempdir }}/mongo-10gen-server-2.6-1.el6.x86_64.rpm"
      throttle: 1
      with_items:
        - "{{ secondary.stdout_lines[0] }}"
        - "{{ secondary.stdout_lines[1] }}"

... secondary变量仅在play_hosts[0]上具有有用的值。 它将在剧中的任何其他主机上未定义。 您没有显示您的剧本的 output，但我希望这个剧本在您的辅助节点上失败。

您真的想通过仅针对相关节点的播放来处理这种“仅在某些节点上运行”行为。 您可以使用group_by模块创建动态的节点组。 例如，如果我们假设您的bash/checkmaster.sh脚本输出主节点的名称，我们可以执行以下操作：

---
- hosts: all
  gather_facts: false
  tasks:
    - name: check master node
      script:
        cmd: bash/checkmaster.sh
      register: master

    - set_fact:
        is_master: "{{ master.stdout_lines[0] == inventory_hostname }}"

    - group_by:
        key: "role_{{ 'master' if is_master else 'secondary' }}"

此播放完成后，您将拥有一个名为role_master的组，其中包含主节点，以及一个名为role_secondary的组，其中包含辅助节点。 然后，您可以像这样在随后的游戏中定位这些：

- hosts: role_master
  gather_facts: false
  tasks:
    - debug:
        msg: "tasks on master node"

- hosts: role_secondary
  gather_facts: false
  tasks:
    - debug:
        msg: "tasks on secondary nodes"

我在https://github.com/larsks/so-example-barra51中整理了一个可运行的示例。