使用 ansible 将递增的变量分配给主机列表

Question

我想要的应该很简单，但我似乎找不到答案。我想运行不同输入的数学模拟。我可以访问 40 个服务器的列表（我没有 root 权限）所以我的想法是同时测试 40 个不同的系数集。目前尚不清楚我如何在 ansible 中使用类似 for loop 的语句设置变量并将它们中的每一个分配给不同的服务器。理想情况下，我希望变量列表是类似于 a = numpy.arange(.0,1.,.1) 给我的浮点数。有什么想法吗？

服务器组设置如下： [computingCluster] cic[1:40]

Answer 1

让我们创建一个包含两个剧本的剧本：

首先Play将从每个主机的模板生成主机变量文件。
第二个 Play 将在主机上执行实际任务。

目录结构：

/tmp/ansible
├── [host_vars]
├── inventory
├── my_template.yml.j2
└── playbook.yml

库存文件：

[computingCluster]
cic[1:10]

用于加载主机变量 (http://docs.ansible.com/ansible/intro_inventory.html#splitting-out-host-and-group-specific-data) 的模板 my_template.yml.j2:

coefficient: {{ item.0 }}

有两部剧本的剧本：

---
- hosts: localhost
  connection: local

  tasks:

    - name: Create Variable File for Each host
      template: src=my_template.yml.j2 dest=host_vars/{{ item.1 }}
      with_indexed_items: "{{ groups['computingCluster'] }}"


- hosts: computingCluster

  pre_tasks:

    - name: Load Host Specific Generated Variables
      include_vars: host_vars/{{ inventory_hostname }}


  tasks:

    - debug: var=coefficient

这是结果 ansible-playbook -i inventory playbook.yml:

PLAY [localhost] **************************************************************

TASK: [Create Variable File for Each host] ************************************
ok: [localhost] => (item=(0, 'cic1'))
ok: [localhost] => (item=(1, 'cic2'))
ok: [localhost] => (item=(2, 'cic3'))
ok: [localhost] => (item=(3, 'cic4'))
ok: [localhost] => (item=(4, 'cic5'))
ok: [localhost] => (item=(5, 'cic6'))
ok: [localhost] => (item=(6, 'cic7'))
ok: [localhost] => (item=(7, 'cic8'))
ok: [localhost] => (item=(8, 'cic9'))
ok: [localhost] => (item=(9, 'cic10'))

PLAY [computingCluster] *******************************************************

GATHERING FACTS ***************************************************************
ok: [cic1]
ok: [cic5]
ok: [cic4]
ok: [cic2]
ok: [cic3]
ok: [cic6]
ok: [cic9]
ok: [cic10]
ok: [cic8]
ok: [cic7]

TASK: [debug var=coefficient] *************************************************
ok: [cic1] => {
    "var": {
        "coefficient": "0"
    }
}
ok: [cic2] => {
    "var": {
        "coefficient": "1"
    }
}
ok: [cic3] => {
    "var": {
        "coefficient": "2"
    }
}
ok: [cic4] => {
    "var": {
        "coefficient": "3"
    }
}
ok: [cic6] => {
    "var": {
        "coefficient": "5"
    }
}
ok: [cic5] => {
    "var": {
        "coefficient": "4"
    }
}
ok: [cic7] => {
    "var": {
        "coefficient": "6"
    }
}
ok: [cic8] => {
    "var": {
        "coefficient": "7"
    }
}
ok: [cic9] => {
    "var": {
        "coefficient": "8"
    }
}
ok: [cic10] => {
    "var": {
        "coefficient": "9"
    }
}

PLAY RECAP ********************************************************************
cic1                       : ok=2    changed=0    unreachable=0    failed=0
cic10                      : ok=2    changed=0    unreachable=0    failed=0
cic2                       : ok=2    changed=0    unreachable=0    failed=0
cic3                       : ok=2    changed=0    unreachable=0    failed=0
cic4                       : ok=2    changed=0    unreachable=0    failed=0
cic5                       : ok=2    changed=0    unreachable=0    failed=0
cic6                       : ok=2    changed=0    unreachable=0    failed=0
cic7                       : ok=2    changed=0    unreachable=0    failed=0
cic8                       : ok=2    changed=0    unreachable=0    failed=0
cic9                       : ok=2    changed=0    unreachable=0    failed=0
localhost                  : ok=1    changed=0    unreachable=0    failed=0

您始终可以使用 jinja 模板来使用 coefficient 变量...

参考文献：

http://docs.ansible.com/ansible/playbooks_loops.html#looping-over-a-list-with-an-index

Answer 2


    me@pc:~/Ansible/playbooks/test_iterate$ ansible-playbook test0.yml 

    PLAY ***************************************************************************

    TASK [setup] *******************************************************************
    ok: [srv-db1]
    ok: [srv-db-temp]

    TASK [debug] *******************************************************************
    ok: [srv-db-temp] => {
        "msg": "101"
    }
    ok: [srv-db1] => {
        "msg": "102"
    }

    PLAY RECAP *********************************************************************
    srv-db-temp          : ok=2    changed=0    unreachable=0    failed=0   
    srv-db1              : ok=2    changed=0    unreachable=0    failed=0

test0.yml:

     hosts: srv-dbs
      vars: 
        - priority_start: 100
      tasks:
       - debug: msg="{% for thishost in play_hosts %}{% if inventory_hostname==thishost %}{{ priority_start + loop.index }}{% endif %}{% endfor %}"

使用 ansible 将递增的变量分配给主机列表

Assign incremented variables to list of hosts with ansible

ansible

ansible-playbook