Interface ICfnConditionExpression
Represents a CloudFormation element that can be used within a Condition.
Inherited Members
Namespace: Amazon.CDK
Assembly: Amazon.CDK.dll
Syntax (csharp)
public interface ICfnConditionExpression : IResolvable
Syntax (vb)
Public Interface ICfnConditionExpression
Inherits IResolvable
Remarks
You can use intrinsic functions, such as Fn.conditionIf
,
Fn.conditionEquals
, and Fn.conditionNot
, to conditionally create
stack resources. These conditions are evaluated based on input parameters
that you declare when you create or update a stack. After you define all your
conditions, you can associate them with resources or resource properties in
the Resources and Outputs sections of a template.
You define all conditions in the Conditions section of a template except for
Fn.conditionIf
conditions. You can use the Fn.conditionIf
condition
in the metadata attribute, update policy attribute, and property values in
the Resources section and Outputs sections of a template.
You might use conditions when you want to reuse a template that can create resources in different contexts, such as a test environment versus a production environment. In your template, you can add an EnvironmentType input parameter, which accepts either prod or test as inputs. For the production environment, you might include Amazon EC2 instances with certain capabilities; however, for the test environment, you want to use less capabilities to save costs. With conditions, you can define which resources are created and how they're configured for each environment type.
You can use toString
when you wish to embed a condition expression
in a property value that accepts a string
. For example:
new Queue(this, "MyQueue", new QueueProps {
QueueName = Fn.ConditionIf("Condition", "Hello", "World").ToString()
});