Example of self-referencing security group in AWS

aws-cfn-self-referencing-sg.yaml

Parameters:

  VPC:
    Description: VPC that will be used for Cluster.
    Type: AWS::EC2::VPC::Id

Resources:

  MyTestSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      VpcId: !Ref VPC
      GroupDescription: Just my testing security group.
      Tags:
        - Key: Name
          Value: sg-mytest

  MyTestSecurityGroupIngress:
    Type: AWS::EC2::SecurityGroupIngress
    DependsOn: MyTestSecurityGroup
    Properties:
      Description: Allow access from anywhere to my security group.
      GroupId: !Ref MyTestSecurityGroup
      IpProtocol: tcp
      FromPort: 80
      ToPort: 80
      CidrIp: '0.0.0.0/0'

  MyTestSecurityGroupIngress2:
    Type: AWS::EC2::SecurityGroupIngress
    DependsOn: MyTestSecurityGroup
    Properties:
      GroupId: !Ref MyTestSecurityGroup
      Description: Allow access between security groups.
      IpProtocol: tcp
      FromPort: '0'
      ToPort: '65535'
      SourceSecurityGroupId: !Ref MyTestSecurityGroup