如何将 ansible-playbook --limit 与 IP 地址而不是主机名一起使用？

Question

我们的 INI 样式库存如下所示：

foo-host ansible_host=1.2.3.4 some_var=bla
bar-host ansible_host=5.6.7.8 some_var=blup

我可以使用主机别名将剧本运行限制为单个主机：

$ ansible-playbook playbook.yml --limit foo-host

但我无法通过在 ansible_host 变量中提及主机的 IP 地址来限制运行:

$ ansible-playbook playbook.yml --limit 1.2.3.4
ERROR! Specified hosts and/or --limit does not match any hosts

我想这样做的原因是 Ansible 是由只知道 IP 地址但不知道别名的外部系统触发的。

有没有办法让它工作？修改 IP 地址（例如 ip_1_2_3_4）是可以接受的。

我考虑过的事情：

把它倒过来，通过 IP 地址识别所有主机：
```
1.2.3.4 some_var=bla
5.6.7.8 some_var=blup
```
但现在我们不能再使用漂亮的主机别名了，库存文件的可读性也变差了。
在常规清单之后编写运行的自定义清单脚本，并创建一个类似 ip_1_2_3_4 的组，仅包含该单个主机，因此我们可以使用 --limit ip_1_2_3_4.但是无法从库存脚本访问以前加载的库存，所以我不知道要创建哪些组。
使用 group_by module 动态创建新组。但是因为这是一个任务，所以只有在 --limit 已经确定没有主机匹配该模式之后，它才是运行，而此时 Ansible 只是放弃而不是运行 group_by 任务了。

Answer 1

Q: Playbook running a script running a playbook... it would work, but it's a bit hacky

答：FWIW。可以使用 json_query 并避免脚本。例如

- hosts: all
  gather_facts: false
  tasks:
    - set_fact:
        my_host: "{{ hostvars|dict2items|json_query(query)|first }}"
      vars:
        query: "[?value.ansible_host == '{{ my_host_ip }}' ].key"
      run_once: true
    - add_host:
        hostname: "{{ my_host }}"
        groups: my_group
      run_once: true

- hosts: my_group
  gather_facts: false
  tasks:
    - debug:
        var: inventory_hostname

Q: "Unfortunately I'm running ansible-playbook from AWX, so no wrapper scripts allowed."

A: 运行剧本中的脚本是可能的。例如下面的剧本

- hosts: all
  gather_facts: false
  tasks:
    - set_fact:
        my_host: "{{ lookup('pipe', playbook_dir ~ '/script.sh ' ~ my_host_ip) }}"
      delegate_to: localhost
      run_once: true
    - add_host:
        hostname: "{{ my_host }}"
        groups: my_group
      run_once: true

- hosts: my_group
  gather_facts: false
  tasks:
    - debug:
        var: inventory_hostname

给予

$ ansible-playbook -e 'my_host_ip=10.1.0.53' play.yml

PLAY [all] ********************

TASK [set_fact] ***************
ok: [test_01 -> localhost]

TASK [add_host] ***************
changed: [test_01]

PLAY [my_group] ***************

TASK [debug] ************
ok: [test_03] => {
    "inventory_hostname": "test_03"
}

（让脚本只打印主机名。）

Q: I can limit a playbook run to a single host by using the host alias:

$ ansible-playbook playbook.yml --limit foo-host

But I can't limit the run by mentioning the host's IP address from the ansible_host variable

$ ansible-playbook playbook.yml --limit 1.2.3.4

答：ansible-inventory和jq都可以解析主机。例如脚本

#!/bin/bash
my_host="$(ansible-inventory --list | jq '._meta.hostvars | to_entries[] | select (.value.ansible_host=="'""'") | .key')"
my_host="$(echo $my_host | sed -e 's/^"//' -e 's/"$//')"
echo host: $my_host
ansible-playbook -l $my_host play.yml

有库存

test_01 ansible_host=10.1.0.51
test_02 ansible_host=10.1.0.52
test_03 ansible_host=10.1.0.53

并与 playbook.yml

- hosts: all
  gather_facts: false
  tasks:
    - debug:
        var: inventory_hostname

给予

$ ./script.bash 10.1.0.53
host: test_03

PLAY [all] **********

TASK [debug] ************
ok: [test_03] => {
    "inventory_hostname": "test_03"
}

Answer 2

仍然欢迎更好的解决方案，但目前我正在使用一个小型库存插件来实现它，该插件（与库存脚本相反）可以访问之前添加的库存：

plugins/inventory/ip_based_groups.py

import os.path
import re

from ansible.plugins.inventory import BaseInventoryPlugin
from ansible.inventory.group import Group


PATH_PLACEHOLDER = 'IP_BASED_GROUPS'
IP_RE = re.compile('^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$')


class InventoryModule(BaseInventoryPlugin):
    '''
    This inventory plugin does not create any hosts, but just adds groups based
    on IP addresses. For each host whose ansible_host looks like an IPv4
    address (e.g. 1.2.3.4), a corresponding group is created by prefixing the
    IP address with 'ip_' and replacing dots by underscores (e.g. ip_1_2_3_4).

    Use it by putting the literal string IP_BASED_GROUPS at the end of the list
    of inventory sources.
    '''

    NAME = 'ip_based_groups'

    def verify_file(self, path):
        return self._is_path_placeholder(path)

    def parse(self, inventory, loader, path, cache=True):
        if not self._is_path_placeholder(path):
            return
        for host_name, host in inventory.hosts.items():
            ansible_host = host.vars.get('ansible_host', '')
            if self._is_ip_address(ansible_host):
                group = 'ip_' + ansible_host.replace('.', '_')
                inventory.add_group(group)
                inventory.add_host(host_name, group)

    def _is_path_placeholder(self, path):
        return os.path.basename(path) == PATH_PLACEHOLDER

    def _is_ip_address(self, s):
        return bool(IP_RE.match(s))

ansible.cfg

[defaults]

# Load plugins from these directories.
inventory_plugins = plugins/inventory

# Directory that contains all inventory files, and placeholder to create
# IP-based groups.
inventory = inventory/,IP_BASED_GROUPS

[inventory]

# Enable our custom inventory plugin.
enable_plugins = ip_based_groups, host_list, script, auto, yaml, ini, toml

如何将 ansible-playbook --limit 与 IP 地址而不是主机名一起使用？

How to use ansible-playbook --limit with an IP address, rather than a hostname?

ansible

ansible-inventory