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# `Fn::GetAtt`
The `Fn::GetAtt` intrinsic function returns the value of an attribute from a resource in the template.
## Declaration
### JSON
```
{ "Fn::GetAtt" : [ "logicalNameOfResource", "attributeName" ] }
```
### YAML
Syntax for the full function name:
```
Fn::GetAtt: [ logicalNameOfResource, attributeName ]
```
Syntax for the short form:
```
!GetAtt logicalNameOfResource.attributeName
```
## Parameters
`logicalNameOfResource`
The logical name (also called *logical ID*) of the resource that contains the attribute that you want.
`attributeName`
The name of the resource-specific attribute whose value you want. See the resource's reference page for details about the attributes available for that resource type.
## Return value
The attribute value. For information about `GetAtt` return values for resources, see the documentation for the resources in the [Resource and property reference](aws-template-resource-type-ref.md).
## Examples
### Return an attribute value
The following examples return a string containing the DNS name of the load balancer with the logical name `myELB`.
#### JSON
```
"Fn::GetAtt" : [ "myELB" , "DNSName" ]
```
#### YAML
```
!GetAtt myELB.DNSName
```
#### Return multiple attribute values
The following examples return the `SourceSecurityGroup.OwnerAlias` and `SourceSecurityGroup.GroupName` of the load balancer with the logical name `myELB`.
##### JSON
```
{
"AWSTemplateFormatVersion": "2010-09-09",
"Resources": {
"myELB": {
"Type": "AWS::ElasticLoadBalancing::LoadBalancer",
"Properties": {
"AvailabilityZones": [
"eu-west-1a"
],
"Listeners": [
{
"LoadBalancerPort": "80",
"InstancePort": "80",
"Protocol": "HTTP"
}
]
}
},
"myELBIngressGroup": {
"Type": "AWS::EC2::SecurityGroup",
"Properties": {
"GroupDescription": "ELB ingress group",
"SecurityGroupIngress": [
{
"IpProtocol": "tcp",
"FromPort": 80,
"ToPort": 80,
"SourceSecurityGroupOwnerId": {
"Fn::GetAtt": [
"myELB",
"SourceSecurityGroup.OwnerAlias"
]
},
"SourceSecurityGroupName": {
"Fn::GetAtt": [
"myELB",
"SourceSecurityGroup.GroupName"
]
}
}
]
}
}
}
}
```
##### YAML
```
AWSTemplateFormatVersion: 2010-09-09
Resources:
myELB:
Type: AWS::ElasticLoadBalancing::LoadBalancer
Properties:
AvailabilityZones:
- eu-west-1a
Listeners:
- LoadBalancerPort: '80'
InstancePort: '80'
Protocol: HTTP
myELBIngressGroup:
Type: AWS::EC2::SecurityGroup
Properties:
GroupDescription: ELB ingress group
SecurityGroupIngress:
- IpProtocol: tcp
FromPort: 80
ToPort: 80
SourceSecurityGroupOwnerId: !GetAtt myELB.SourceSecurityGroup.OwnerAlias
SourceSecurityGroupName: !GetAtt myELB.SourceSecurityGroup.GroupName
```
#### Use `Fn::Sub` inside `Fn::GetAtt` function
**Note**
When you use the `AWS::LanguageExtensions` transform, you can use `Fn::GetAtt` in combination with other intrinsic functions. For supported functions, see [Supported functions](#getatt-supported-functions).
The following examples show how to use `Fn::GetAtt` with [`Fn::Sub`](intrinsic-function-reference-sub.md), in conjuction with [`Fn::ForEach`](intrinsic-function-reference-foreach.md), in the `Outputs` section of a template to reduce the template length and verbosity. The use of `Fn::Sub` within `Fn::GetAtt` allows the template to contain one intrinsic function that can reference a different bucket at every iteration of the `Fn::ForEach` call.
##### JSON
```
{
"AWSTemplateFormatVersion": "2010-09-09",
"Transform": "AWS::LanguageExtensions",
"Mappings": {
"Buckets": {
"Properties": {
"Identifiers": ["A", "B", "C"]
}
}
},
"Resources": {
"Fn::ForEach::Buckets": [
"Identifier",
{"Fn::FindInMap": ["Buckets", "Properties", "Identifiers"]},
{
"S3Bucket${Identifier}": {
"Type": "AWS::S3::Bucket",
"Properties": {
"AccessControl": "PublicRead",
"MetricsConfigurations": [
{
"Id": {"Fn::Sub": "EntireBucket${Identifier}"}
}
],
"WebsiteConfiguration": {
"IndexDocument": "index.html",
"ErrorDocument": "error.html",
"RoutingRules": [
{
"RoutingRuleCondition": {
"HttpErrorCodeReturnedEquals": "404",
"KeyPrefixEquals": "out1/"
},
"RedirectRule": {
"HostName": "ec2-11-22-333-44.compute-1.amazonaws.com",
"ReplaceKeyPrefixWith": "report-404/"
}
}
]
}
},
"DeletionPolicy": "Retain",
"UpdateReplacePolicy": "Retain"
}
}
]
},
"Outputs": {
"Fn::ForEach::BucketOutputs": [
"Identifier",
{"Fn::FindInMap": ["Buckets", "Properties", "Identifiers"]},
{
"Fn::ForEach::GetAttLoop": [
"Property",
["Arn", "DomainName", "WebsiteURL"],
{
"S3Bucket${Identifier}${Property}": {
"Value": {
"Fn::GetAtt": [{"Fn::Sub": "S3Bucket${Identifier}"}, {"Ref": "Property"}]
}
}
}
]
}
]
}
}
```
##### YAML
```
AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Mappings:
Buckets:
Properties:
Identifiers:
- A
- B
- C
Resources:
'Fn::ForEach::Buckets':
- Identifier
- Fn::FindInMap:
- Buckets
- Properties
- Identifiers
- 'S3Bucket${Identifier}':
Type: AWS::S3::Bucket
Properties:
AccessControl: PublicRead
MetricsConfigurations:
- Id:
Fn::Sub: 'EntireBucket${Identifier}'
WebsiteConfiguration:
IndexDocument: index.html
ErrorDocument: error.html
RoutingRules:
- RoutingRuleCondition:
HttpErrorCodeReturnedEquals: '404'
KeyPrefixEquals: out1/
RedirectRule:
HostName: ec2-11-22-333-44.compute-1.amazonaws.com
ReplaceKeyPrefixWith: report-404/
DeletionPolicy: Retain
UpdateReplacePolicy: Retain
Outputs:
'Fn::ForEach::BucketOutputs':
- Identifier
- Fn::FindInMap:
- Buckets
- Properties
- Identifiers
- 'Fn::ForEach::GetAttLoop':
- Property
- - Arn
- DomainName
- WebsiteURL
- 'S3Bucket${Identifier}${Property}':
Value: !GetAtt
- !Sub 'S3Bucket${Identifier}'
- !Ref Property
```
## Supported functions
When you use the [AWS::LanguageExtensions transform](transform-aws-languageextensions.md), you can use the following functions within the `Fn::GetAtt` function. This is true with either the `Fn::GetAtt` logical resource name or the `Fn::GetAtt` attribute name.
+ [`Fn::Base64`](intrinsic-function-reference-base64.md)
+ [`Fn::FindInMap`](intrinsic-function-reference-findinmap.md)
+ [`Fn::If`](intrinsic-function-reference-conditions.md#intrinsic-function-reference-conditions-if)
+ [`Fn::Join`](intrinsic-function-reference-join.md)
+ [`Fn::Sub`](intrinsic-function-reference-sub.md)
+ [`Fn::ToJsonString`](intrinsic-function-reference-ToJsonString.md)
+ [`Ref`](intrinsic-function-reference-ref.md)
When the `AWS::LanguageExtensions` transform is not used:
+ The `Fn::GetAtt` attribute name can only use the [`Ref`](intrinsic-function-reference-ref.md) function.
+ The `Fn::GetAtt` logical resource name can't use functions. You must specify a string that's a resource's logical ID.