yaml SAM local with dynamo db

I'm trying to create a set of lambda functions that depend on DynamoDB. I've written a valid SAM template like this:

---
AWSTemplateFormatVersion: 2010-09-09

Transform: AWS::Serverless-2016-10-31

Resources:
  Get:
    Type: AWS::Serverless::Function
    Properties:
      Handler: ./lambdas/get/main
      Runtime: go1.x
      Events:
        PostEvent:
          Type: Api
          Properties:
            Path: /
            Method: get
  Portfolios:
    Type: AWS::DynamoDB::Table
    TableName: "entities"
    Properties: 
      AttributeDefinitions: 
        - 
          AttributeName: "Id"
          AttributeType: "S"
        - 
          AttributeName: "Name"
          AttributeType: "S"
      KeySchema: 
        - 
          AttributeName: "Id"
          KeyType: "HASH"
        - 
          AttributeName: "Name"
          KeyType: "RANGE"
      ProvisionedThroughput: 
        ReadCapacityUnits: 5
        WriteCapacityUnits: 5
      Tags:
        - Key: foo
          Value: bar         


Outputs:
  Endpoint:
    Value:  !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/"

but when I try to execute any of the lambdas they timeout when trying to call putItem. What do I need to do to ensure that my lambdas can talk to my local dynamodb?

    sess := session.Must(session.NewSessionWithOptions(session.Options{
        SharedConfigState: session.SharedConfigEnable,
    }))
    endpoint := "localhost:3000"
    db := dynamodb.New(sess, &aws.Config{
        Endpoint: &endpoint,
    })
    entity := &models.Entities{}
    json.Unmarshal([]byte(event.Body), portfolio)

    av, err := dynamodbattribute.MarshalMap(entity)
    if err != nil {
        fmt.Println("Got error marshalling:")
        fmt.Println(err.Error())
        os.Exit(1)
    }

    input := &dynamodb.PutItemInput{
        Item:      av,
        TableName: aws.String("entities"),
    }

    _, err = db.PutItem(input) // Times out here
    if err != nil {
        fmt.Println("Got error calling PutItem:")
        fmt.Println(err.Error())
        return events.APIGatewayProxyResponse{StatusCode: 500}, nil
    }

How can I make sure that my table is even being created correctly?

turns out SAM local will NOT create the dynamodb table: https://github.com/awslabs/aws-sam-cli/issues/105

To do so you'll have to create the docker container manually and create the tables outside of SAM.