IAM Role via CloudFormation Error in Principle - amazon-web-services

Question

I am trying to create an IAM role via cloudformation for an existing IAM user as principle and an existing dynamodb table. I have verified through yamllint and yaml is well-formatted and yet cloudformation is complaining about malformatted file.
Following is my cloudformation template:
AWSTemplateFormatVersion: 2010-09-09
Parameters:
vTableName:
Type: String
Description: the tablename
Default: arn:aws:dynamodb:ap-southeast-2:1234567:table/test-table
vUserName:
Type: String
Description: New account username
Default: mytestuser
Resources:
DynamoRoleForTest:
Type: 'AWS::IAM::Role'
Properties:
AssumeRolePolicyDocument:
Statement:
- Effect: Allow
Principal:
AWS:
- !Sub 'arn:aws:iam::${AWS::AccountId}:user/${vUserName}'
Action:
- sts:AssumeRole
Path: /
Policies:
- PolicyName: DynamoPolicy
PolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
- Action:
- dynamodb:BatchGet*
- dynamodb:DescribeStream
- dynamodb:DescribeTable
- dynamodb:Get*
- dynamodb:Query
- dynamodb:Scan
Resource: !Ref vTableName
and following is error I receive,when I try to create this template:
Syntax errors in policy. (Service: AmazonIdentityManagement; Status Code: 400; Error Code: MalformedPolicyDocument; Request ID: 237dd218-a2a2-4194-9063-104f8022cb80)
Thanks for any advice.

Answer 1

There is not-needed - in your Action:
- Action:
Therefore, your template should be (removed -):
AWSTemplateFormatVersion: 2010-09-09
Parameters:
vTableName:
Type: String
Description: the tablename
Default: arn:aws:dynamodb:ap-southeast-2:1234567:table/test-table
vUserName:
Type: String
Description: New account username
Default: mytestuser
Resources:
DynamoRoleForTest:
Type: 'AWS::IAM::Role'
Properties:
AssumeRolePolicyDocument:
Statement:
- Effect: Allow
Principal:
AWS:
- !Sub 'arn:aws:iam::${AWS::AccountId}:user/${vUserName}'
Action:
- sts:AssumeRole
Path: /
Policies:
- PolicyName: DynamoPolicy
PolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
Action:
- dynamodb:BatchGet*
- dynamodb:DescribeStream
- dynamodb:DescribeTable
- dynamodb:Get*
- dynamodb:Query
- dynamodb:Scan
Resource: !Ref vTableName
Principle is fine, assuming it exists.