AWSTemplateFormatVersion

AWSTemplateFormatVersion: 2010-09-09
Description: >
  Creates a cross-account role that your AWS account can assume
  in order to accept a VPC peering connection in the other account.
  This is pretty confusing, so to clarify,
  1. Run this CloudFormation in the OTHER account to create the cross-account role.
  2. Your account requests a peering connection with the other account.
  3. Your account assumes the role in order to access the other account
     and accept the peering connection.
Parameters:
  PeerRequesterAccountId:
    Type: String
Resources:
  AcceptVpcPeeringRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Principal:
              AWS: !Ref PeerRequesterAccountId
            Action:
              - 'sts:AssumeRole'
            Effect: Allow
      Path: /
      Policies:
        - PolicyName: root
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action: 'ec2:AcceptVpcPeeringConnection'
                Resource: '*'