简化基于字典的Oracle配置文件模板

Question

我试图使用一个模板，生成包含信息的配置文件，如主机，端口，用户名，密码，…
我想使用一个模板并在模板任务中传递标签，因此模板将选择在相应标签中定义的变量，即:

- name: generate config
template:
src: /test/debezium_oracle_cdc_source.j2
dest: "/config/debz-oracle-test_1.json"
vars:
tags: "{{ oracle['tag1']  }}"
bootstrap_servers: "kafka:9092"
- name: generate config
template:
src: /test/debezium_oracle_cdc_source.j2
dest: "/config/debz-oracle-test_2.json"
vars:
tags: "{{ oracle['tag2']  }}"
bootstrap_servers: "kafka:9092"

变量文件

oracle:
tag1:
tables:
- DEPT
- EMPLOYEE
db_host: localhost
db_name: root
db_user: root
db_port: 1521

tag2:
tables:
- SALES
- SALES_ITEM
db_host: localhost
db_name: root
db_user: root
db_port: 1521

debezium_oracle_cdc_source.j2:

{
"database.hostname": "{{ db_host }}",
"database.port": "{{ db_port }}"
}

基本上，我想让我的变量文件更可读。

Answer 1

您的问题来自tags是Ansible中的保留词，因为它是一个现有的关键字。

这可以通过一个简单的任务来复制和确认:

- debug:
msg: "{{ tags }}"
vars:
tags: I guess I am buggy?

出错:

fatal: [localhost]: FAILED! => 
msg: |-
The task includes an option with an undefined variable. 
The error was: 'tags' is undefined. 'tags' is undefined

The error appears to be in '/usr/local/ansible/play.yml': 
line 7, column 7, but may be elsewhere in the file 
depending on the exact syntax problem.

The offending line appears to be:

tasks:
- debug:
^ here

这可以很容易地修复，例如，通过在变量前面加上下划线:

- debug:
msg: "{{ _tags }}"
vars:
_tags: I guess I am buggy?

这将产生预期的:

ok: [localhost] => 
msg: I guess I am buggy?

---

所以在模板debezium_oracle_cdc_source的情况下。包含:j2

{
"database.hostname": "{{ _tags.db_host }}",
"database.port": "{{ _tags.db_port }}"
}

和任务:

- template:
src: debezium_oracle_cdc_source.j2
dest: "/config/debz-oracle-test_{{ item }}.json"
loop: "{{ range(1, 3) }}"
vars:
_tags: "{{ oracle['tag' ~ item]  }}"
oracle:
tag1:
db_host: host1.localhost
db_port: 1234
tag2:
db_host: host2.localhost
db_port: 5678

我们得到了两个预期的JSON:

• /config/debz-oracle-test_1.json:

  {
  "database.hostname": "host1.localhost",
  "database.port": "1234"
  }
  

• /config/debz-oracle-test_2.json:

  
  {
  "database.hostname": "host2.localhost",
  "database.port": "5678"
  }
  

Answer 2

在模板中使用字典标签

{
"database.hostname": "{{ tags.db_host }}",
"database.port": "{{ tags.db_port }}"
}