Build a dynamic proxy using RPC and internal routing

Work in progress (requires uWSGI 1.9.14, we use PyPy as the engine)

step 1: build your mapping function

we use the hostname as the mapping (you can use whatever you need)

import uwsgi

def my_mapper(hostname):
    return "127.0.0.1:3031"

uwsgi.register_rpc('the_mapper', my_mapper)

save it as myfuncs.py

step 2: building a routing table

[uwsgi]
; enable the pypy engine
pypy-home = /opt/pypy
; execute the myfuncs.py file (the 'the_mapper' rpc function will be registered)
pypy-exec = myfuncs.py

; bind to a port
http-socket = :9090

; let's define our routing table

; at every request (route-run execute the action without making check, use it instead of --route .*) run the_mapper passing HTTP_HOST as argument
; and place the result in the MYNODE variable
route-run = rpcvar:MYNODE the_mapper ${HTTP_HOST}
; print the MYNODE variable (just for fun)
route-run = log:${MYNODE}
; proxy the request to the chosen backend node
route-run = http:${MYNODE}

; enable offloading for automagic non-blocking behaviour
; a good value for offloading is the number of cpu cores
offload-threads = 2