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ansible - Ansible：如何编写以服务为中心的清单？

问题描述

Ansible 通常以主机为中心工作：如果您的主机在清单中的多个组中具有一些主机变量，则该主机的所有变量将被合并，并且具有相同名称的变量将相互覆盖。例子：

# Inventory

[app_stages:children]
stage_development
stage_acceptance

[stage_development]
localhost db_unique_name=scdev oracle_version_db=12.1.0.2 oracle_edition_db=SE2
localhost db_unique_name=ecdev oracle_version_db=12.1.0.2 oracle_edition_db=EE

[stage_acceptance]
localhost db_unique_name=scacp oracle_version_db=18 oracle_edition_db=SE2
localhost db_unique_name=ecacp oracle_version_db=18 oracle_edition_db=EE

# Playbook
- name: test inventory
  hosts: "{{ hostgroup }}"

  tasks:
    - name: show variables
      debug:
        msg: host {{ ansible_hostname }}, db_name = {{ db_unique_name }}, db_version = {{ oracle_version_db }}, db_edition = {{ oracle_edition_db }}

结果：

   ansible-playbook playbook_1.yml -i inventory_1 -e hostgroup=stage_development

   TASK [show variables]  ******************************************************************************************************************
   ok: [localhost] => {
       "msg": "host server_1, db_name = ecacp, db_version = 18, db_edition = EE"
   }

这表明即使我要求 ansible 在 stage_development 上工作，它也只会使用并显示在另一个组中设置的变量。

我需要一种不同的方法：首先我想用一些基本参数（例如数据库名称、版本等，见上文）来指定服务。是否将它们中的一部分或全部部署到同一主机是次要的。这个工作但不是那么优雅，因为有关服务的信息在剧本中，而不是在稍后应该由一些外部工具（CMS）生成的清单中：

# Inventory
[app_stages:children]
stage_development
stage_acceptance

[stage_development:children]
srv_scdev
srv_ecdev

[stage_acceptance:children]
srv_scacp
srv_ecacp

[srv_scdev]
localhost

[srv_ecdev]
localhost

[srv_scacp]
localhost

[srv_ecacp]
localhost

# Playbook
---

- name: stage development, setup database scdev
  hosts: srv_scdev
  vars:
    db_unique_name: scdev
    oracle_version_db: 12.1.0.2
    oracle_edition_db: SE2
  tasks:
    - name: show variables
      debug:
        msg: host {{ ansible_hostname }}, db_name = {{ db_unique_name }}, db_version = {{ oracle_version_db }}, db_edition = {{ oracle_edition_db }}

- name: stage development, setup database ecdev
  hosts: srv_ecdev
  vars:
    db_unique_name: ecdev
    oracle_version_db: 12.1.0.2
    oracle_edition_db: EE
  tasks:
    - name: show variables
      debug:
        msg: host {{ ansible_hostname }}, db_name = {{ db_unique_name }}, db_version = {{ oracle_version_db }}, db_edition = {{ oracle_edition_db }}

- name: stage acceptance, setup database scacp
  hosts: srv_scacp
  vars:
    db_unique_name: scacp
    oracle_version_db: 18
    oracle_edition_db: SE2
  tasks:
    - name: show variables
      debug:
        msg: host {{ ansible_hostname }}, db_name = {{ db_unique_name }}, db_version = {{ oracle_version_db }}, db_edition = {{ oracle_edition_db }}

- name: stage acceptance, setup database ecacp
  hosts: srv_ecacp
  vars:
    db_unique_name: ecacp
    oracle_version_db: 18
    oracle_edition_db: EE
  tasks:
    - name: show variables
      debug:
        msg: host {{ ansible_hostname }}, db_name = {{ db_unique_name }}, db_version = {{ oracle_version_db }}, db_edition = {{ oracle_edition_db }}

...

问题：如何正确/可重复使用/优雅？

标签： ansibleansible-inventory

解决方案

ansible_host一个更改最少的解决方案是通过设置并为库存本身引入一个假名称来扩展您的库存，例如

# Inventory

[app_stages:children]
stage_development
stage_acceptance

[stage_development]
dev1 ansible_host=localhost db_unique_name=scdev oracle_version_db=12.1.0.2 oracle_edition_db=SE2
dev2 ansible_host=localhost db_unique_name=ecdev oracle_version_db=12.1.0.2 oracle_edition_db=EE

[stage_acceptance]
stage1 ansible_host=localhost db_unique_name=scacp oracle_version_db=18 oracle_edition_db=SE2
stage2 ansible_host=localhost db_unique_name=ecacp oracle_version_db=18 oracle_edition_db=EE

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