This is the new *Amazon CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [Amazon CloudFormation User Guide](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::VpcLattice::Rule
<a name="aws-resource-vpclattice-rule"></a>

Creates a listener rule. Each listener has a default rule for checking connection requests, but you can define additional rules. Each rule consists of a priority, one or more actions, and one or more conditions. For more information, see [Listener rules](https://docs.amazonaws.cn/vpc-lattice/latest/ug/listeners.html#listener-rules) in the *Amazon VPC Lattice User Guide*.

## Syntax
<a name="aws-resource-vpclattice-rule-syntax"></a>

To declare this entity in your Amazon CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-vpclattice-rule-syntax.json"></a>

```
{
  "Type" : "AWS::VpcLattice::Rule",
  "Properties" : {
      "[Action](#cfn-vpclattice-rule-action)" : {{Action}},
      "[ListenerIdentifier](#cfn-vpclattice-rule-listeneridentifier)" : {{String}},
      "[Match](#cfn-vpclattice-rule-match)" : {{Match}},
      "[Name](#cfn-vpclattice-rule-name)" : {{String}},
      "[Priority](#cfn-vpclattice-rule-priority)" : {{Integer}},
      "[ServiceIdentifier](#cfn-vpclattice-rule-serviceidentifier)" : {{String}},
      "[Tags](#cfn-vpclattice-rule-tags)" : {{[ Tag, ... ]}}
    }
}
```

### YAML
<a name="aws-resource-vpclattice-rule-syntax.yaml"></a>

```
Type: AWS::VpcLattice::Rule
Properties:
  [Action](#cfn-vpclattice-rule-action): {{
    Action}}
  [ListenerIdentifier](#cfn-vpclattice-rule-listeneridentifier): {{String}}
  [Match](#cfn-vpclattice-rule-match): {{
    Match}}
  [Name](#cfn-vpclattice-rule-name): {{String}}
  [Priority](#cfn-vpclattice-rule-priority): {{Integer}}
  [ServiceIdentifier](#cfn-vpclattice-rule-serviceidentifier): {{String}}
  [Tags](#cfn-vpclattice-rule-tags): {{
    - Tag}}
```

## Properties
<a name="aws-resource-vpclattice-rule-properties"></a>

`Action`  <a name="cfn-vpclattice-rule-action"></a>
Describes the action for a rule.  
*Required*: Yes  
*Type*: [Action](aws-properties-vpclattice-rule-action.md)  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`ListenerIdentifier`  <a name="cfn-vpclattice-rule-listeneridentifier"></a>
The ID or ARN of the listener.  
*Required*: No  
*Type*: String  
*Pattern*: `^((listener-[0-9a-z]{17})|(arn(:[a-z0-9]+([.-][a-z0-9]+)*){2}(:([a-z0-9]+([.-][a-z0-9]+)*)?){2}:service/svc-[0-9a-z]{17}/listener/listener-[0-9a-z]{17}))$`  
*Minimum*: `20`  
*Maximum*: `2048`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Match`  <a name="cfn-vpclattice-rule-match"></a>
The rule match.  
*Required*: Yes  
*Type*: [Match](aws-properties-vpclattice-rule-match.md)  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Name`  <a name="cfn-vpclattice-rule-name"></a>
The name of the rule. The name must be unique within the listener. The valid characters are a-z, 0-9, and hyphens (-). You can't use a hyphen as the first or last character, or immediately after another hyphen.  
If you don't specify a name, CloudFormation generates one. However, if you specify a name, and later want to replace the resource, you must specify a new name.  
*Required*: No  
*Type*: String  
*Pattern*: `^(?!rule-)(?![-])(?!.*[-]$)(?!.*[-]{2})[a-z0-9-]+$`  
*Minimum*: `3`  
*Maximum*: `63`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Priority`  <a name="cfn-vpclattice-rule-priority"></a>
The priority assigned to the rule. Each rule for a specific listener must have a unique priority. The lower the priority number the higher the priority.  
*Required*: Yes  
*Type*: Integer  
*Minimum*: `1`  
*Maximum*: `100`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`ServiceIdentifier`  <a name="cfn-vpclattice-rule-serviceidentifier"></a>
The ID or ARN of the service.  
*Required*: No  
*Type*: String  
*Pattern*: `^((svc-[0-9a-z]{17})|(arn(:[a-z0-9]+([.-][a-z0-9]+)*){2}(:([a-z0-9]+([.-][a-z0-9]+)*)?){2}:service/svc-[0-9a-z]{17}))$`  
*Minimum*: `20`  
*Maximum*: `2048`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Tags`  <a name="cfn-vpclattice-rule-tags"></a>
The tags for the rule.  
*Required*: No  
*Type*: Array of [Tag](aws-properties-vpclattice-rule-tag.md)  
*Minimum*: `0`  
*Maximum*: `50`  
*Update requires*: [No interruption](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

## Return values
<a name="aws-resource-vpclattice-rule-return-values"></a>

### Ref
<a name="aws-resource-vpclattice-rule-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the Amazon Resource Name (ARN) of the rule.

For more information about using the `Ref` function, see [https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-ref.html).

### Fn::GetAtt
<a name="aws-resource-vpclattice-rule-return-values-fn--getatt"></a>

The `Fn::GetAtt` intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.

For more information about using the `Fn::GetAtt` intrinsic function, see [https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-getatt.html).

#### 
<a name="aws-resource-vpclattice-rule-return-values-fn--getatt-fn--getatt"></a>

`Arn`  <a name="Arn-fn::getatt"></a>
The Amazon Resource Name (ARN) of the rule.

`Id`  <a name="Id-fn::getatt"></a>
The ID of the listener.