dagyr_tornado_proxy

A simple tornado proxy which wraps dagyr DAGs

Disclaimer: this is still a prototype, its very likely things won't quite work :)

High-Level Operation

The DAG execution is allowed to modify the request/response in hooks (ingress, egress, etc.) which will then be used by the proxy. The basic request flow is:

accept -> create state -> ingress hook -> make downstream request -> egress hook -> serve response

RequestState

This object encapsulates the http request/response state. This is what the underlying proxy uses to determine how to handle the request. This contains 4 objects: pristine_request, request, pristine_response, response. "pristine" meaning untouched-- specifically that we don't allow modification of these entries as processing_nodes may want to switch based off of the original request/response before mutation.

RequestState object format

Note: this is still a rough skeleton, so this will change dramatically

These objects are really just dicts of data. The data today looks something like:

    {
        'code': 200,
        'headers': {'X-Foo': 'bar'},
        'body': 'the body!',
    }

These objects are used by the underlying proxy to represent the transaction at the various phases. This will be expanded to include transaction_overrideable configuration (timeouts, lb options, etc.).