HTTP middleware for Go 1.8 and beyond.
go-mw is a small library for making http middleware in Go. It is not a web framework: Handling routes, rate limiting et al is up to some other library (or framework, your pick), but handling middleware is where this is key.
go-mw is based upon two observations I have done while programming web servers with Ring in Clojure:
- Passing data around as values gives you the power to separate domain logic with serialisation and socket concerns
- Wrapping the context (db transactions, caches, user id etc) in custom types means you can implicitly provide Context to the user, and avoid unnecessarily many error checks.
The former is not as common in Go as far as I know: All the HTTP frameworks I
have seen so far focus on embracing the (w *http.ResponseWriter, r http.Request) pattern in some way – either by adding additional functions on
top of the ResponseWriter (typically WriteJSON or something similar) or just
using the plain old http.ServeHTTP.
Of course, this is necessary if you can't opt out of the web framework and need to stream while processing/doing domain logic; whether it is due to performance or something else. And passing by value will be slower. However, for the vast majority of users, pass-by-value will not likely be slow enough for it to matter.
Copyright © 2017 Jean Niklas L'orange
Distributed under the BSD 3-clause license, which is available in the file LICENSE.