如何创建自己的ansible module

什么是 ansible module?

Ansible modules 是一种使用python写成的一些功能块，可以在yaml文件中调用，也就是playbook中可以调用的模块，例如常见的模块 copy ， debug

Ansible 本身就提供了很多很多的模块地址

什么时候和什么情况下我们会需要自己写module?

绝大多数情况下，我们不需要创建自己的模块module,然而，有些时候官方提供的模块无法提供我们需要的功能，我们只能通过自己的模块来处理一些代码

通常，module和哪些提供了丰富api接口的服务对接起来会更加流畅，例如Github 或者 Pivotal ，当然我们可以通过url来和这些服务进行交互，但是，有时候这个方法太不cool 了，我们要牛B的方法

创建一个简单的例子

幸运的是创建一个ansible module是非常容易的

我们将创建一个简单的例子：从github上删除或者创建一个repo

我们先来一个简单的输出的例子

创建如下文件：

play.yml  
[library]
  |_ github_repo.py
  |_ test_github_repo.py

play.yml

[library]

|_ github_repo.py

|_ test_github_repo.py

library/github_repo.py

Python

#!/usr/bin/python

from ansible.module_utils.basic import *

def main():

    module = AnsibleModule(argument_spec={})
    response = {"hello": "world"}
    module.exit_json(changed=False, meta=response)


if __name__ == '__main__':  
    main()

#!/usr/bin/python

from ansible.module_utils.basic import *

def main():

module = AnsibleModule(argument_spec={})

response = {"hello": "world"}

module.exit_json(changed=False, meta=response)

if __name__ == '__main__':

main()

Notes

main() 是你的程序入口
#!/usr/bin/python is 这个是必须的，就和些shell脚本一样
AnsibleModule 是从 ansible.module_utils.basic 总导入的，import * 必须是导入全部的 *
AnsibleModule 有一些已经写好的方法让我们调用，例如exit_json

play.yml

YAML

- hosts: localhost
  tasks:
    - name: Test that my module works
      github_repo: 
      register: result

    - debug: var=result

- hosts: localhost

tasks:

- name: Test that my module works

github_repo:

- debug: var=result

上边是一个非常简单的例子，调用了我们的module: github_repo，并注册到一个变量result中，并打印这个变量的值

我们来跑一下:

$ ansible-playbook play.yml

1 2	$ ansible-playbook play.yml

(note: 命令中未指定 -i ，所以旧的版本可能需要你手动指定一个host文件-i).

输出:

Bash

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

TASK [setup] *******************************************************************  
ok: [localhost]

TASK [Test that my module works] ***********************************************  
ok: [localhost]

TASK [debug] *******************************************************************  
ok: [localhost] => {  
    "result": {
        "changed": false, 
        "meta": {
            "hello": "world"
        }
    }
}

PLAY RECAP *********************************************************************  
localhost                  : ok=3    changed=0    unreachable=0    failed=0

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

TASK [setup] *******************************************************************

ok: [localhost]

TASK [Test that my module works] ***********************************************

ok: [localhost]

TASK [debug] *******************************************************************

ok: [localhost] => {

"result": {

"changed": false,

"meta": {

"hello": "world"

}

PLAY RECAP *********************************************************************

localhost : ok=3 changed=0 unreachable=0 failed=0

非常漂亮，运行成功了

加入一些变量

当然，一个好的模块一定会有输入的，因为我们要创建repo，所以我们直接拿来一些代码复用 (其实就是创建一个repo需要的参数)

YAML

    - name: Create a github Repo
      github_repo:
        github_auth_key: "..."
        name: "Hello-World",
        description: "This is your first repository",
        private: yes
        has_issues: no
        has_wiki: no
        has_downloads: no
        state: present
      register: result

- name: Create a github Repo

github_repo:

github_auth_key: "..."

description: "This is your first repository",

private: yes

has_issues: no

has_wiki: no

has_downloads: no

state: present

好，然后我们在代码中添加如下内容:

Python

def main():

  fields = {
        "github_auth_key": {"required": True, "type": "str"},
        "name": {"required": True, "type": "str" },
        "description": {"required": False, "type": "str"},
        "private": {"default": False, "type": "bool" },
        "has_issues": {"default": True, "type": "bool" },
        "has_wiki": {"default": True, "type": "bool" },
        "has_downloads": {"default": True, "type": "bool" },
        "state": {
            "default": "present", 
            "choices": ['present', 'absent'],  
            "type": 'str' 
        },
    }

    module = AnsibleModule(argument_spec=fields)
    module.exit_json(changed=False, meta=module.params)

def main():

fields = {

"github_auth_key": {"required": True, "type": "str"},

"name": {"required": True, "type": "str" },

"description": {"required": False, "type": "str"},

"private": {"default": False, "type": "bool" },

"has_issues": {"default": True, "type": "bool" },

"has_wiki": {"default": True, "type": "bool" },

"has_downloads": {"default": True, "type": "bool" },

"state": {

"default": "present",

"choices": ['present', 'absent'],

"type": 'str'

}

module = AnsibleModule(argument_spec=fields)

module.exit_json(changed=False, meta=module.params)

注意:

输入的变量是字典形式错在的
参数类型: str, bool, dict, list, …
我们可以指定一些default，required之类的.

上边的例子，我们什么都没有做，只是把传递的值有传递到了exit_json

如果这时候跑一下的话，输出结果将会是我们传递的字典内容

好的，我们现在将一下如何处理这些传递进module的参数

在pythyon的头部我们添加两个函数（函数名称随意，但是要和下变的对应）

Python

def github_repo_present(data):  
    has_changed = False
    meta = {"present": "not yet implemented"}
    return (has_changed, meta)

def github_repo_absent(data=None):  
    has_changed = False
    meta = {"absent": "not yet implemented"}

def github_repo_present(data):

has_changed = False

meta = {"present": "not yet implemented"}

return (has_changed, meta)

def github_repo_absent(data=None):

has_changed = False

meta = {"absent": "not yet implemented"}

These are the functions that will actually do the work. Back in our main()method, let’s add some code to call the desired function:

这两个方法是真正用来处理数据的地方,让我们在main还数中添加如何调用这两个函数的部分

Python

def main():  
    fields = {..}
    choice_map = {
      "present": github_repo_present,
      "absent": github_repo_absent, 
    }
    module = AnsibleModule(argument_spec=fields)
    has_changed, result = choice_map.get(module.params['state'])(module.params)
    module.exit_json(changed=has_changed, meta=result)

def main():

fields = {..}

choice_map = {

"present": github_repo_present,

"absent": github_repo_absent,

}

module = AnsibleModule(argument_spec=fields)

has_changed, result = choice_map.get(module.params['state'])(module.params)

module.exit_json(changed=has_changed, meta=result)

We use a map to map the state provided to a function that will handle that state.

我们通过map来控制这两个函数

最后的事情就是，让我们的函数真正具有创建和删除的功能（就是调用github的接口，原理还是通过url来访问接口）

Python

def github_repo_present(data):

    api_key = data['github_auth_key']

    del data['state']
    del data['github_auth_key']

    headers = {
        "Authorization": "token {}" . format(api_key)
    }
    url = "{}{}" . format(api_url, '/user/repos')
    result = requests.post(url, json.dumps(data), headers=headers)

    if result.status_code == 201:
        return False, True, result.json()
    if result.status_code == 422:
        return False, False, result.json()

    # default: something went wrong
    meta = {"status": result.status_code, 'response': result.json()}
    return True, False, meta


def github_repo_absent(data=None):  
    headers = {
        "Authorization": "token {}" . format(data['github_auth_key'])
    }
    url = "{}/repos/{}/{}" . format(api_url, "toast38coza", data['name'])
    result = requests.delete(url, headers=headers)

    if result.status_code == 204:
        return False, True, {"status": "SUCCESS"}
    if result.status_code == 404:
        result = {"status": result.status_code, "data": result.json()}
        return False, False, result
    else:
        result = {"status": result.status_code, "data": result.json()}
        return True, False, result

def github_repo_present(data):

api_key = data['github_auth_key']

del data['state']

del data['github_auth_key']

headers = {

"Authorization": "token {}" . format(api_key)

}

url = "{}{}" . format(api_url, '/user/repos')

result = requests.post(url, json.dumps(data), headers=headers)

if result.status_code == 201:

return False, True, result.json()

if result.status_code == 422:

return False, False, result.json()

# default: something went wrong

meta = {"status": result.status_code, 'response': result.json()}

return True, False, meta

def github_repo_absent(data=None):

headers = {

"Authorization": "token {}" . format(data['github_auth_key'])

}

url = "{}/repos/{}/{}" . format(api_url, "toast38coza", data['name'])

result = requests.delete(url, headers=headers)

if result.status_code == 204:

return False, True, {"status": "SUCCESS"}

if result.status_code == 404:

result = {"status": result.status_code, "data": result.json()}

return False, False, result

else:

result = {"status": result.status_code, "data": result.json()}

return True, False, result

我们再添加一块来删除刚刚创建的repo:

YAML

- hosts: localhost
  vars: 
    - github_token: "..."
  tasks:
    - name: Create a github Repo
      github_repo:
        github_auth_key: "{{github_token}}"
        name: "Hello-World"
        description: "This is your first repository"
        private: yes
        has_issues: no
        has_wiki: no
        has_downloads: no

    - name: Delete that repo 
      github_repo:
        github_auth_key: "{{github_token}}"
        name: "Hello-World"
        state: absent

- hosts: localhost

vars:

- github_token: "..."

tasks:

- name: Create a github Repo

github_repo:

github_auth_key: "{{github_token}}"

description: "This is your first repository"

private: yes

has_issues: no

has_wiki: no

has_downloads: no

- name: Delete that repo

github_repo:

github_auth_key: "{{github_token}}"

state: absent

最后一步，我们来添加一些主事，和测试的例子

Python

DOCUMENTATION = '''  
---
module: github_repo  
short_description: Manage your repos on Github  
'''

EXAMPLES = '''  
- name: Create a github Repo
  github_repo:
    github_auth_key: "..."
    name: "Hello-World"
    description: "This is your first repository"
    private: yes
    has_issues: no
    has_wiki: no
    has_downloads: no
  register: result

- name: Delete that repo 
  github_repo:
    github_auth_key: "..."
    name: "Hello-World"
    state: absent
  register: result
'''

DOCUMENTATION = '''

---

module: github_repo

short_description: Manage your repos on Github

'''

EXAMPLES = '''

- name: Create a github Repo

github_repo:

github_auth_key: "..."

description: "This is your first repository"

private: yes

has_issues: no

has_wiki: no

has_downloads: no

- name: Delete that repo

github_repo:

github_auth_key: "..."

state: absent

'''

结论：

你已经成功的创建了你第一个module.

完整代码：

#!/usr/bin/python

DOCUMENTATION = '''
---
module: github_repo
short_description: Manage your repos on Github
'''

EXAMPLES = '''
- name: Create a github Repo
  github_repo:
    github_auth_key: "..."
    name: "Hello-World"
    description: "This is your first repository"
    private: yes
    has_issues: no
    has_wiki: no
    has_downloads: no
  register: result
- name: Delete that repo 
  github_repo:
    github_auth_key: "..."
    name: "Hello-World"
    state: absent
  register: result
'''

from ansible.module_utils.basic import *
import requests

api_url = "https://api.github.com"


def github_repo_present(data):

    api_key = data['github_auth_key']

    del data['state']
    del data['github_auth_key']

    headers = {
        "Authorization": "token {}" . format(api_key)
    }
    url = "{}{}" . format(api_url, '/user/repos')
    result = requests.post(url, json.dumps(data), headers=headers)

    if result.status_code == 201:
        return False, True, result.json()
    if result.status_code == 422:
        return False, False, result.json()

    # default: something went wrong
    meta = {"status": result.status_code, 'response': result.json()}
    return True, False, meta


def github_repo_absent(data=None):
    headers = {
        "Authorization": "token {}" . format(data['github_auth_key'])
    }
    url = "{}/repos/{}/{}" . format(api_url, "toast38coza", data['name'])
    result = requests.delete(url, headers=headers)

    if result.status_code == 204:
        return False, True, {"status": "SUCCESS"}
    if result.status_code == 404:
      result = {"status": result.status_code, "data": result.json()}
        return False, False, result
    else:
        result = {"status": result.status_code, "data": result.json()}
        return True, False, result


def main():

    fields = {
        "github_auth_key": {"required": True, "type": "str"},
        "name": {"required": True, "type": "str"},
        "description": {"required": False, "type": "str"},
        "private": {"default": False, "type": "bool"},
        "has_issues": {"default": True, "type": "bool"},
        "has_wiki": {"default": True, "type": "bool"},
        "has_downloads": {"default": True, "type": "bool"},
        "state": {
            "default": "present",
            "choices": ['present', 'absent'],
            "type": 'str'
        },
    }

    choice_map = {
        "present": github_repo_present,
        "absent": github_repo_absent,
    }

    module = AnsibleModule(argument_spec=fields)
    is_error, has_changed, result = choice_map.get(
        module.params['state'])(module.params)

    if not is_error:
        module.exit_json(changed=has_changed, meta=result)
    else:
        module.fail_json(msg="Error deleting repo", meta=result)


if __name__ == '__main__':
    main()

100

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#!/usr/bin/python

DOCUMENTATION = '''

---

module: github_repo

short_description: Manage your repos on Github

'''

EXAMPLES = '''

- name: Create a github Repo

github_repo:

github_auth_key: "..."

description: "This is your first repository"

private: yes

has_issues: no

has_wiki: no

has_downloads: no

- name: Delete that repo

github_repo:

github_auth_key: "..."

state: absent

'''

from ansible.module_utils.basic import *

import requests

api_url = "https://api.github.com"

def github_repo_present(data):

api_key = data['github_auth_key']

del data['state']

del data['github_auth_key']

headers = {

"Authorization": "token {}" . format(api_key)

}

url = "{}{}" . format(api_url, '/user/repos')

result = requests.post(url, json.dumps(data), headers=headers)

if result.status_code == 201:

return False, True, result.json()

if result.status_code == 422:

return False, False, result.json()

# default: something went wrong

meta = {"status": result.status_code, 'response': result.json()}

return True, False, meta

def github_repo_absent(data=None):

headers = {

"Authorization": "token {}" . format(data['github_auth_key'])

}

url = "{}/repos/{}/{}" . format(api_url, "toast38coza", data['name'])

result = requests.delete(url, headers=headers)

if result.status_code == 204:

return False, True, {"status": "SUCCESS"}

if result.status_code == 404:

result = {"status": result.status_code, "data": result.json()}

return False, False, result

else:

result = {"status": result.status_code, "data": result.json()}

return True, False, result

def main():

fields = {

"github_auth_key": {"required": True, "type": "str"},

"name": {"required": True, "type": "str"},

"description": {"required": False, "type": "str"},

"private": {"default": False, "type": "bool"},

"has_issues": {"default": True, "type": "bool"},

"has_wiki": {"default": True, "type": "bool"},

"has_downloads": {"default": True, "type": "bool"},

"state": {

"default": "present",

"choices": ['present', 'absent'],

"type": 'str'

}

choice_map = {

"present": github_repo_present,

"absent": github_repo_absent,

}

module = AnsibleModule(argument_spec=fields)

is_error, has_changed, result = choice_map.get(

module.params['state'])(module.params)

if not is_error:

module.exit_json(changed=has_changed, meta=result)

else:

module.fail_json(msg="Error deleting repo", meta=result)

if __name__ == '__main__':

main()

翻译原文地址：http://blog.toast38coza.me/custom-ansible-module-hello-world/

About
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Zhiming Zhang

Senior devops at Appannie

一个奔跑在运维路上的胖子

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熟悉Ansible,Docker,Zabbix,Python,Shell,Iptables的这么一个devops

什么是 ansible module?

什么时候和什么情况下我们会需要自己写module?

创建一个简单的例子

结论：

Zhiming Zhang

Latest posts by Zhiming Zhang (see all)

本文共 3 个回复

王 2017/03/12 10:11

kevin 2018/08/05 11:24

Zhiming Zhang 博主 2018/08/06 07:28