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

# AWS::NetworkFirewall::FirewallPolicy Dimension
<a name="aws-properties-networkfirewall-firewallpolicy-dimension"></a>

The value to use in an Amazon CloudWatch custom metric dimension. This is used in the `PublishMetrics` custom action. A CloudWatch custom metric dimension is a name/value pair that's part of the identity of a metric. 

AWS Network Firewall sets the dimension name to `CustomAction` and you provide the dimension value. 

For more information about CloudWatch custom metric dimensions, see [Publishing Custom Metrics](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/publishingMetrics.html#usingDimensions) in the [Amazon CloudWatch User Guide](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/WhatIsCloudWatch.html).

## Syntax
<a name="aws-properties-networkfirewall-firewallpolicy-dimension-syntax"></a>

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

### JSON
<a name="aws-properties-networkfirewall-firewallpolicy-dimension-syntax.json"></a>

```
{
  "[Value](#cfn-networkfirewall-firewallpolicy-dimension-value)" : {{String}}
}
```

### YAML
<a name="aws-properties-networkfirewall-firewallpolicy-dimension-syntax.yaml"></a>

```
  [Value](#cfn-networkfirewall-firewallpolicy-dimension-value): {{String}}
```

## Properties
<a name="aws-properties-networkfirewall-firewallpolicy-dimension-properties"></a>

`Value`  <a name="cfn-networkfirewall-firewallpolicy-dimension-value"></a>
The value to use in the custom metric dimension.  
*Required*: Yes  
*Type*: String  
*Pattern*: `^[a-zA-Z0-9-_ ]+$`  
*Minimum*: `1`  
*Maximum*: `128`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)