如何在HEAT user_data中传递json/list值给模板

Question

需要将资源组中的user_data替换为comma_delimited_list中的动态值。

%index%不工作

heat_template_version: 2015-10-15
test_parameter:
type: comma_delimited_list
label: test param  list
description: test descr
default: 'test_param_1,test_param_2'
.......
...... 
type: OS::Heat::ResourceGroup
properties:
.........
.........
user_data:
    str_replace:
      template: |
        get the local value of the instance : $val
      params:
        $val: { get_param: [ test_parameter, %index% ] } 
        
        

如何在HEAT-user_data中传递json/list值给模板

Answer 1

遗憾的是，基于aws-cloudformation的仍然在一定程度上限制了您通常可以做的事情，而特定于热的语言(仍然基于aws-cloudformation)也受到同样的限制。

通常，最好的解决方案是在模板的顶部放置一个"选择"列表，并将其中的一些选择传递给资源。在下面的例子中，其中一个选项要求安装一个特定的web应用程序(从nginx和apache)，并将其作为变量传递给模板的user-data部分:

heat_template_version: 2015-04-30
description: >
  Hello world HOT template that just defines a single server.
  Contains just base features to verify base HOT support.
parameters:
  key_name:
    type: string
    description: Name of an existing key pair to use for the server
    default: "topcat-01"
    constraints:
      - custom_constraint: nova.keypair
  flavor:
    type: string
    description: Flavor for the server to be created
    default: m1.normal
    constraints:
      - custom_constraint: nova.flavor
  image:
    type: string
    description: Image ID or image name to use for the server
    default: Ubuntu-1404lts-32-Cloud
    constraints:
      - custom_constraint: glance.image
  my_network:
    type: string
    description: Neutron Network
    default: public-internet-access
    constraints:
      - custom_constraint: neutron.network
  application-install:
    type: string
    default: apache
    constraints: 
      - allowed_values: [apache, nginx]
        description: Value must be one of 'apache', or 'nginx'
resources:
  server:
    type: OS::Nova::Server
    properties:
      key_name: { get_param: key_name }
      image: { get_param: image }
      flavor: { get_param: flavor }
      security_groups: 
        - default
      name: test-single-topcat-instance
      networks:
        - network: { get_param: my_network }
      user_data_format: RAW
      user_data:
        str_replace:
          template: |
            #!/bin/bash
            myapp="$selectedapp01"
            echo "MY APP IS $myapp"
            PATH=$PATH:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin
            case $myapp in
            apache)
                echo "INSTALLING APACHE"
                if [ -f /etc/debian_version ]
                then
                   aptitude -y update
                   aptitude -y install apache2
                fi
                if [ -f /etc/redhat-release ]
                then
                   yum -y install httpd
                   chkconfig httpd on
                   echo "" >> /var/www/html/index.html
                   service httpd start
                fi
                ;;
            nginx)
                echo "INSTALLING NGINX"
                if [ -f /etc/debian_version ]
                then
                   aptitude -y update
                   aptitude -y install nginx-full
                fi
                if [ -f /etc/redhat-release ]
                then
                   yum -y install nginx
                   chkconfig nginx on
                   service nginx start
                fi
                ;;
            esac
          params:
            $selectedapp01: {get_param: application-install}
outputs:
  server_networks:
    description: The networks of the deployed server
    value: { get_attr: [server, networks] }

从上面的例子中，"application-install"参数(可以是apache或nginx)将被解释为user-data部分末尾的"$selectedapp01"，以及user-data部分开头的"$myapp" (myapp="$selectedapp01")。

这并不完美，但却是正常的做法。大多数云形成部署工具从一组"问答"构造最终模板，并且您完成了静态(或半静态)模板。

我在这里添加的这个例子，会问你很多东西，并设置一些默认值。

希望能有所帮助。