AWS::Lambda::Permission
The AWS::Lambda::Permission
resource grants an Amazon 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
. To grant permission to an organization
defined in Amazon Organizations, specify the organization ID as the PrincipalOrgID
. For Amazon
services, the principal is a domain-style identifier defined by the service, like s3.amazonaws.com
or
sns.amazonaws.com
. For Amazon 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.
If your function has a function URL, you can specify the FunctionUrlAuthType
parameter. This adds a condition to your
permission that only applies when your function URL's AuthType
matches the specified FunctionUrlAuthType
. For
more information about the AuthType
parameter, see
Security and auth model for Lambda function URLs.
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 Amazon CloudFormation template, use the following syntax:
JSON
{ "Type" : "AWS::Lambda::Permission", "Properties" : { "Action" :
String
, "EventSourceToken" :String
, "FunctionName" :String
, "FunctionUrlAuthType" :String
, "Principal" :String
, "PrincipalOrgID" :String
, "SourceAccount" :String
, "SourceArn" :String
} }
YAML
Type: AWS::Lambda::Permission Properties: Action:
String
EventSourceToken:String
FunctionName:String
FunctionUrlAuthType:String
Principal:String
PrincipalOrgID: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]+|[*])$
Minimum:
1
Maximum:
256
Update requires: Replacement
EventSourceToken
-
For Alexa Smart Home functions, a token that the invoker must supply.
Required: No
Type: String
Pattern:
^[a-zA-Z0-9._\-]+$
Minimum:
1
Maximum:
256
Update requires: Replacement
FunctionName
-
The name or ARN 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
Pattern:
^(arn:(aws[a-zA-Z-]*)?:lambda:)?([a-z]{2}((-gov)|(-iso([a-z]?)))?-[a-z]+-\d{1}:)?(\d{12}:)?(function:)?([a-zA-Z0-9-_]+)(:(\$LATEST|[a-zA-Z0-9-_]+))?$
Minimum:
1
Maximum:
140
Update requires: Replacement
-
FunctionUrlAuthType
-
The type of authentication that your function URL uses. Set to
AWS_IAM
if you want to restrict access to authenticated users only. Set toNONE
if you want to bypass IAM authentication to create a public endpoint. For more information, see Security and auth model for Lambda function URLs.Required: No
Type: String
Allowed values:
AWS_IAM | NONE
Update requires: Replacement
Principal
-
The Amazon Web Services service, Amazon Web Services account, IAM user, or IAM role 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:
^.*$
Minimum:
1
Maximum:
256
Update requires: Replacement
PrincipalOrgID
-
The identifier for your organization in Amazon Organizations. Use this to grant permissions to all the Amazon Web Services accounts under this organization.
Required: No
Type: String
Pattern:
^o-[a-z0-9]{10,32}$
Minimum:
12
Maximum:
34
Update requires: Replacement
SourceAccount
-
For Amazon Web Services service, the ID of the Amazon Web Services account that owns the resource. Use this together with
SourceArn
to ensure that the specified account owns the resource. 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}$
Minimum:
12
Maximum:
12
Update requires: Replacement
SourceArn
-
For Amazon Web Services services, the ARN of the Amazon resource that invokes the function. For example, an Amazon S3 bucket or Amazon SNS topic.
Note that Lambda configures the comparison using the
StringLike
operator.Required: No
Type: String
Pattern:
^arn:(aws[a-zA-Z0-9-]*):([a-zA-Z0-9\-])+:([a-z]{2}((-gov)|(-iso([a-z]?)))?-[a-z]+-\d{1})?:(\d{12})?:(.*)$
Minimum:
12
Maximum:
1024
Update requires: Replacement
Examples
Cross Account Invoke
Grant account 123456789012 permission to invoke a function resource named lambdaFunction
created in
the same template.
YAML
permission: Type: AWS::Lambda::Permission Properties: FunctionName: !Ref lambdaFunction Action: lambda:InvokeFunction Principal: 123456789012
Public Function URL Invoke
Grant public, unauthenticated access to invoke your function named lambdaFunction
via its function URL.
YAML
permissionForURLInvoke: Type: AWS::Lambda::Permission Properties: FunctionName: !Ref lambdaFunction FunctionUrlAuthType: 'NONE' Action: lambda:InvokeFunctionUrl Principal: '*'
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