Serverless: [AWS] Unable to create role resource with policy

Question

I am learning how to make use of serverless framework and i am at the point of creating roles on which some specific functions will assume, but cloudformation throws an error indicating:

An error occurred: LambdaAdminRole - Unknown field Policies (Service: AmazonIdentityManagement; Status Code: 400; Error Code: MalformedPolicyDocument; Request ID: 07cb3916-78c5-11e9-b0f6-37c9c6cd9547).

The way how the resource is defined in serverless is like this:

resources:
  Resources:
    LambdaAdminRole:
      Type: AWS::IAM::Role
      Properties:
        RoleName: ${self:service}-${self:provider.stage}-lambda-admin-role
        AssumeRolePolicyDocument:
          Version: '2017'
          Statement:
            - Effect: Allow
              Principal:
                Service:
                  - lambda.amazonaws.com
              Action: sts:AssumeRole
          Policies:
            - PolicyName: ${self:service}-${self:provider.stage}-lambda-cognito-admin-policy
              PolicyDocument:
                Version: '2017'
                Statement:
                  - Effect: Allow
                    Action:
                      - cognito-idp:ListUsersInGroup
                      - cognito-idp:ListUsers
                    Resource:
                      - 'Fn::Join':
                          - ':'
                          - - 'arn:aws:cognito-idp'
                            - ${self:provider.region}
                            - Ref: 'AWS::AccountId'
                            - 'userpool/*'

Is this not the proper way to create a role with serverless?, i was following the examples that serverless's docuentation show: https://serverless.com/framework/docs/providers/aws/guide/iam/

Answer 1

You have incorrect indentation, Policies attribute belongs to Properties , not to AssumeRolePolicyDocument which is the case in your document.

(unindent the whole Policies section by one)

Answer 2

如官方文档中所述， Policies属于Properties ，而不属于AssumeRolePolicyDocument