Can't get it to use my existing DynamoDB table

[matthewkogan]

I can't seem to get Flask-Session to use my existing DynamoDB table. It works fine locally, but not once deployed to AWS.

Here's my setup code:

endpoint_url = 'http://localhost:8000' if not os.getenv('BUILD_ENV') else None
dynamodb_resource = boto3.resource(
    'dynamodb',
    region_name='eu-west-1',
    endpoint_url=endpoint_url
)

app.config.update(
    {
        "SESSION_TYPE": "dynamodb",
	"SESSION_DYNAMODB": dynamodb_resource,
	"SESSION_DYNAMODB_TABLE": "my-sessions"
    }
)

Session(app)

I can see that it's just trying to create a new table instead of using the one I've already set up for it:
botocore.exceptions.ClientError: An error occurred (AccessDeniedException) when calling the CreateTable operation: User: arn:aws:sts::[redacted]:assumed-role/my-task-role/[redacted] is not authorized to perform: dynamodb:CreateTable on resource: arn:aws:dynamodb:eu-west-1:[redacted]:table/my-sessions because no identity-based policy allows the dynamodb:CreateTable action

I have checked that all the role my app is running with has all the necessary permissions on the table.

I can see that there is code committed since 0.8.0 was released that adds a SESSION_DYNAMODB_TABLE_EXISTS parameter. Is this what I need? If so, when is there likely to be a new release that includes this? Or is there another solution?

Thank you.