Ansible：尝试一次性在多个区域中创建多个 EC2 实例

Question

我正在尝试创建一个 AWS EC2 ansible playbook：

1) 首先在三个 Region 上分别分配一个 VPC，它们是： us-west-1、ap-northeast-1 和 eu-west-1。

2) 为每个区域查找最新的 ubuntu AMI (ec2_ami_search)，

3) 然后使用从 1) 和 2) 中发现的结果， 使用最新的 ubuntu AMI（针对该区域）为每个区域创建一个 EC2 实例 具有可用区 us-west-1a、ap-northeast-1a 和 eu-west-1a。

使用 Ansible，我对步骤 1) 和 2) 没有任何问题，这很简单：

> 

  tasks:
  - name: create a vpc
    ec2_vpc:
      state: present
      region: "{{ item.region }}"
      internet_gateway: True
      resource_tags: { env: production}
      cidr_block: 10.0.0.0/16
      subnets:
        - cidr: 10.0.0.0/24
          az: "{{ item.az }}"
          resource_tags:
            env: production
            tier: public
      route_tables:
        - subnets:
          - 10.0.0.0/24
          routes:
          - dest: 0.0.0.0/0
            gw: igw
    with_items:
      - region: us-west-1
        az: us-west-1a
      - region: ap-northeast-1
        az: ap-northeast-1a
      - region: eu-west-1
        az: eu-west-1a
...
  - name: Get the ubuntu trusty AMI
    ec2_ami_search: distro=ubuntu release=trusty virt=hvm region={{ item }}
    with_items:
      - us-west-1
      - ap-northeast-1
      - eu-west-1
    register: ubuntu_image
...
>

以及带有调试模块的 ubuntu_image 变量的输出：

TASK: [print out ubuntu images] *********************************************** 
ok: [localhost] => {
    "ubuntu_image": {
        "changed": false, 
        "msg": "All items completed", 
        "results": [
            {
                "aki": null, 
                "ami": "ami-b33dccf7", 
                "ari": null, 
                "changed": false, 
                "invocation": {
                    "module_args": "distro=ubuntu release=trusty virt=hvm region=us-west-1", 
                    "module_name": "ec2_ami_search"
                }, 
                "item": "us-west-1", 
                "serial": "20150629", 
                "tag": "release"
            }, 
            {
                "aki": null, 
                "ami": "ami-9e5cff9e", 
                "ari": null, 
                "changed": false, 
                "invocation": {
                    "module_args": "distro=ubuntu release=trusty virt=hvm region=ap-northeast-1", 
                    "module_name": "ec2_ami_search"
                }, 
                "item": "ap-northeast-1", 
                "serial": "20150629", 
                "tag": "release"
            }, 
            {
                "aki": null, 
                "ami": "ami-7c4b0a0b", 
                "ari": null, 
                "changed": false, 
                "invocation": {
                    "module_args": "distro=ubuntu release=trusty virt=hvm region=eu-west-1", 
                    "module_name": "ec2_ami_search"
                }, 
                "item": "eu-west-1", 
                "serial": "20150629", 
                "tag": "release"
            }
        ]
    }
}

但是，我不知道如何进行第 3 步） 从 ubuntu_image 寄存器变量中获取结果 然后确定给定 EC2 实例属于 3 个 AMI 和子网中的哪一个。 请参阅下面的解决方法，我手动硬编码了 ami 和子网值 我只是从上面的 ubuntu_image 打印输出中得到的：

  - name: start the instances
    ec2:
      image: "{{ item.ami }}"  # MANUALLY HARDCODED
      region: "{{ item.region }}"
      instance_type: "{{ instance_type }}"
      assign_public_ip: True
      key_name: "{{ item.name }}"
      group: ["http deployment", "ssh deployment", "outbound deployment"]
      instance_tags: { Name: "{{ item.name }}", type: ss, env: production}
      exact_count: "{{ count }}"
      count_tag: {  Name: "{{ item.name }}" }
      vpc_subnet_id: "{{ item.subnet }}" #MANUALLY HARDCODED
      wait: yes
    register: ec2
    with_items:
      - region: us-west-1
        name: ss12
        ami: ami-b33dccf7  # MANUALLY HARDCODED
        subnet: subnet-35a22550  # MANUALLY HARDCODED
      - region: ap-northeast-1
        name: ss21
        ami: ami-9e5cff9e  # MANUALLY HARDCODED
        subnet: subnet-88c47dff  # MANUALLY HARDCODED
      - region: eu-west-1
        name: ss32
        ami: ami-7c4b0a0b  # MANUALLY HARDCODED
        subnet: subnet-23f59554  # MANUALLY HARDCODED

虽然硬编码 ami/子网有效，但您能想出一个解决方案来避免对 ami/子网进行这种硬编码吗？ 我尝试弄乱 set_fact 无济于事，因为我无法让它成为“区域到 ami”值映射的字典

Answer 1

请记住，Ansible 是一个“可插入”系统，因此为您自己定制它真的很容易。有时，它甚至比尝试使用“原生”模块找到解决方法更容易、更快捷。

在您的情况下，您可以轻松编写自己的自定义 lookup_plugin 来搜索正确的 subnet。

例如：

1. 在您的主文件夹中创建一个名为 lookup_plugins 的文件夹。
2. 创建一个名为ansible.cfg 的文件（如果没有的话）

[defaults]
lookup_plugins = lookup_plugins

在lookup_plugins 中创建一个名为subnets.py 的文件

import boto.vpc
class LookupModule(object):
    def __init__(self, basedir=None, **kwargs):
        self.basedir = basedir
        self.plugin_name = 'subnets'
    def run(self, regions, variable=None, **kwargs):
        if not isinstance(regions, list):
            regions = [regions]
        for region in regions:
            return [boto.vpc.connect_to_region(region).get_all_subnets()[0].id]

上面的简单代码将在给定区域中查找子网。当然你可以随意定制它。

然后在你的剧本中引用这个插件来找到正确的子网：

例子：

- hosts: localhost
  gather_facts: no
  tasks:
    - name: Start instance
      debug: msg="Starting instance {{ item.ami }} in {{ item.region }} in {{ item.subnet }}"
      with_items:
        - region: us-west-1
          name: ss12
          ami: ami-b33dccf7  
          subnet: "{{ lookup('subnets', 'us-west-1') }}"
        - region: ap-northeast-1
          name: ss21
          ami: ami-9e5cff9e  
          subnet: "{{ lookup('subnets', 'ap-northeast-1') }}"
        - region: eu-west-1
          name: ss32
          ami: ami-7c4b0a0b 
          subnet: "{{ lookup('subnets', 'ap-northeast-1') }}"

在您的情况下，您可能需要引用正确的 AMI 和关联的 Region 。

Answer 2

如果您仍然想在没有其他模块帮助的情况下执行此操作，您可以计算服务器的模“%”和子网长度：

"{{subnets[item.0 | int % subnets | length | int].aws_ec2_subnets}}"

示例代码

变量：

subnets:
  - {zone: "us-east-1a", aws_ec2_subnets: 'subnet-123'}
  - {zone: "us-east-1b", aws_ec2_subnets: 'subnet-456'}
  - {zone: "us-east-1d", aws_ec2_subnets: 'subnet-789'}

server_list:
  - server1
  - server2
  - server3

任务：

- name: Create new ec2 instance
  ec2:
    profile: "{{aws_profile}}"
    key_name: "{{aws_key_name}}"
    group_id: "{{aws_security_group}}"
    instance_type: "{{aws_instance_type}}"
    image: "{{aws_ami}}"
    region: "{{region}}"
    exact_count: "1"
    #instance_profile_name: none
    wait: yes
    wait_timeout: 500
    volumes: "{{volumes}}"
    monitoring: no
    vpc_subnet_id: "{{subnets[item.0 | int % subnets | length | int].aws_ec2_subnets}}"
    assign_public_ip: no
    tenancy: default
    termination_protection: yes
    instance_tags:
      App: "{{app_name}}"
      Environment: "{{environment_type}}"
      Platform: "{{platform_name}}"
      Name: "{{item.1}}"
    count_tag:
      App: "{{app_name}}"
      Environment: "{{environment_type}}"
      Platform: "{{platform_name}}"
      Name: "{{item.1}}"
  register: ec2_new_instance
  with_indexed_items:
    - "{{server_list}}"

Answer 3

这就是我的做法。 launchNodes.yml 只是一个带有一些标记的简单 ec2

- debug:
    msg: "launching {{ nodeCount }} nodes in these subnets {{ec2SubnetIds}}"

- name: clear finalSubnetList
  set_fact:
    finalSubnetList: []

- name: build final list
  set_fact:
    finalSubnetList: "{{ finalSubnetList }} + [ '{{ ec2SubnetIds[ ( ec2subnet|int % ec2SubnetIds|length)|int ] }}' ]"
  with_sequence: count={{nodeCount}}  
  loop_control:
    loop_var: ec2subnet

- debug:
    msg: "finalSubnetList {{finalSubnetList}} "

- include_tasks: launchNodes.yml
      ec2SubnetId="{{ finalSubnetList[index|int -1] }}"
      nodeCount=1
  with_sequence: count="{{ finalSubnetList|length }}"
  loop_control:
    loop_var: index