AWS::Lambda::Permission
The AWS::Lambda::Permission
resource grants an AWS service or another account permission to use a
function. You can apply the policy at the function level, or specify a qualifier to
restrict access to a single
version or alias. If you use a qualifier, the invoker must use the full Amazon Resource
Name (ARN) of that version
or alias to invoke the function.
To grant permission to another account, specify the account ID as the Principal
. For AWS
services, the principal is a domain-style identifier defined by the service, like
s3.amazonaws.com
or
sns.amazonaws.com
. For AWS services, you can also specify the ARN of the associated resource as the
SourceArn
. If you grant permission to a service principal without specifying the source, other
accounts could potentially configure resources in their account to invoke your Lambda
function.
This resource adds a statement to a resource-based permission policy for the function. For more information about function policies, see Lambda Function Policies.
Syntax
To declare this entity in your AWS CloudFormation template, use the following syntax:
JSON
{ "Type" : "AWS::Lambda::Permission", "Properties" : { "Action" :
String
, "EventSourceToken" :String
, "FunctionName" :String
, "Principal" :String
, "SourceAccount" :String
, "SourceArn" :String
} }
YAML
Type: AWS::Lambda::Permission Properties: Action:
String
EventSourceToken:String
FunctionName:String
Principal:String
SourceAccount:String
SourceArn:String
Properties
Action
-
The action that the principal can use on the function. For example,
lambda:InvokeFunction
orlambda:GetFunction
.Required: Yes
Type: String
Pattern:
(lambda:[*]|lambda:[a-zA-Z]+|[*])
Update requires: Replacement
EventSourceToken
-
For Alexa Smart Home functions, a token that must be supplied by the invoker.
Required: No
Type: String
Minimum:
0
Maximum:
256
Pattern:
[a-zA-Z0-9._\-]+
Update requires: Replacement
FunctionName
-
The name of the Lambda function, version, or alias.
Name formats
-
Function name -
my-function
(name-only),my-function:v1
(with alias). -
Function ARN -
arn:aws:lambda:us-west-2:123456789012:function:my-function
. -
Partial ARN -
123456789012:function:my-function
.
You can append a version number or alias to any of the formats. The length constraint applies only to the full ARN. If you specify only the function name, it is limited to 64 characters in length.
Required: Yes
Type: String
Minimum:
1
Maximum:
140
Pattern:
(arn:(aws[a-zA-Z-]*)?:lambda:)?([a-z]{2}(-gov)?-[a-z]+-\d{1}:)?(\d{12}:)?(function:)?([a-zA-Z0-9-_]+)(:(\$LATEST|[a-zA-Z0-9-_]+))?
Update requires: Replacement
-
Principal
-
The AWS service or account that invokes the function. If you specify a service, use
SourceArn
orSourceAccount
to limit who can invoke the function through that service.Required: Yes
Type: String
Pattern:
.*
Update requires: Replacement
SourceAccount
-
For Amazon S3, the ID of the account that owns the resource. Use this together with
SourceArn
to ensure that the resource is owned by the specified account. It is possible for an Amazon S3 bucket to be deleted by its owner and recreated by another account.Required: No
Type: String
Pattern:
\d{12}
Update requires: Replacement
SourceArn
-
For AWS services, the ARN of the AWS resource that invokes the function. For example, an Amazon S3 bucket or Amazon SNS topic.
Required: No
Type: String
Pattern:
arn:(aws[a-zA-Z0-9-]*):([a-zA-Z0-9\-])+:([a-z]{2}(-gov)?-[a-z]+-\d{1})?:(\d{12})?:(.*)
Update requires: Replacement
Examples
Cross Account Invoke
Grant account 123456789012 permission to invoke a function resource named function
created in
the same template.
YAML
permission: Type: AWS::Lambda::Permission Properties: FunctionName: !GetAtt function.Arn Action: lambda:InvokeFunction Principal: 123456789012
Amazon S3 Notifications
Grant Amazon S3 permission to invoke a function resource named function
created in the same
template, to process notifications for a bucket resource named bucket
.
JSON
"s3Permission": { "Type": "AWS::Lambda::Permission", "Properties": { "FunctionName": { "Fn::GetAtt": [ "function", "Arn" ] }, "Action": "lambda:InvokeFunction", "Principal": "s3.amazonaws.com", "SourceAccount": { "Ref": "AWS::AccountId" }, "SourceArn": { "Fn::GetAtt": [ "bucket", "Arn" ] } } }
YAML
s3Permission: Type: AWS::Lambda::Permission Properties: FunctionName: !GetAtt function.Arn Action: lambda:InvokeFunction Principal: s3.amazonaws.com SourceAccount: !Ref 'AWS::AccountId' SourceArn: !GetAtt bucket.Arn