如果该值在Python(即,它不从CloudFormation参数激活的),你可以使用已知字典可选属性添加到资源在对流层模板:
from troposphere import Template
import troposphere.elasticloadbalancing as elb
template = Template()
my_idle_timeout = 30 # replace this with your method for determining the value
my_elb_params = {}
if my_idle_timeout is not None:
my_elb_params['ConnectionSettings'] = elb.ConnectionSettings(
IdleTimeout=my_idle_timeout,
)
my_elb = template.add_resource(elb.LoadBalancer(
'ElasticLoadBalancer',
Listeners=[
elb.Listener(
LoadBalancerPort="80",
InstancePort="80",
Protocol="HTTP",
),
],
**my_elb_params,
))
print(template.to_json())
如果该值从CloudFormation参数起源,你需要创建一个Condition
测试参数的值,如果没有提供参数值,则使用Ref("AWS::NoValue")
,例如:
from troposphere import Template, Parameter, Equals, Ref, If
import troposphere.elasticloadbalancing as elb
template = Template()
my_idle_timeout = template.add_parameter(Parameter(
"ElbIdleTimeout",
Description="Idle timeout for the Elastic Load Balancer",
Type="Number",
))
no_idle_timeout = "NoIdleTimeout"
template.add_condition(
no_idle_timeout,
Equals(Ref(my_idle_timeout), ""),
)
my_elb = template.add_resource(elb.LoadBalancer(
'ElasticLoadBalancer',
Listeners=[
elb.Listener(
LoadBalancerPort="80",
InstancePort="80",
Protocol="HTTP",
),
],
ConnectionSettings=If(
no_idle_timeout,
Ref("AWS::NoValue"),
elb.ConnectionSettings(
IdleTimeout=Ref(my_idle_timeout),
),
),
))
print(template.to_json())
谢谢。这样可行。在经过仔细阅读(设置'instance.ImageId')之后,我在README文件中只找到了这个特性的参考,也许文档可以更突出地突出这一点。 –