API Gateway ResourcePolicy

apigw_template.yml

Resources:
  MyAPI:
    Type: AWS::Serverless::Api
    Properties:
      StageName: dev
      DefinitionBody:
        swagger: 2.0
        info:
          title: !Ref AWS::StackName
        x-amazon-apigateway-policy:
          Version: 2012-10-17
          Statement:
          - Effect: Allow
            Principal: "*"
            Action: execute-api:Invoke
            Resource: !Sub arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:*
            Condition:
              IpAddress:
                aws:SourceIp: !If
                  - ProdDeployment
                  - [ "10.0.0.1" ]
                  - [
                      "10.0.0.2", # you can
                      "10.0.0.3/32", # list them
                      "10.0.0.4/32" # like this
                    ]