Oxy is a Go library with HTTP handlers that enhance HTTP standard library:
- Buffer retries and buffers requests and responses
- Stream passes-through requests, supports chunked encoding with configurable flush interval
- Forward forwards requests to remote location and rewrites headers
- Roundrobin is a round-robin load balancer
- Circuit Breaker Hystrix-style circuit breaker
- Connlimit Simultaneous connections limiter
- Ratelimit Rate limiter (based on tokenbucket algo)
- Trace Structured request and response logger
It is designed to be fully compatible with http standard library, easy to customize and reuse.
- Initial design is completed
- Covered by tests
- Used as a reverse proxy engine in Vulcand
Every handler is http.Handler, so writing and plugging in a middleware is easy. Let us write a simple reverse proxy as an example:
import ( "net/http" "github.com/vulcand/oxy/v2/forward" "github.com/vulcand/oxy/v2/testutils" ) // Forwards incoming requests to whatever location URL points to, adds proper forwarding headers fwd := forward.New(false) redirect := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { // let us forward this request to another server req.URL = testutils.ParseURI("http://localhost:63450") fwd.ServeHTTP(w, req) }) // that's it! our reverse proxy is ready! s := &http.Server{ Addr: ":8080", Handler: redirect, } s.ListenAndServe()As a next step, let us add a round robin load-balancer:
import ( "net/http" "github.com/vulcand/oxy/v2/forward" "github.com/vulcand/oxy/v2/roundrobin" ) // Forwards incoming requests to whatever location URL points to, adds proper forwarding headers fwd := forward.New(false) lb, _ := roundrobin.New(fwd) lb.UpsertServer(url1) lb.UpsertServer(url2) s := &http.Server{ Addr: ":8080", Handler: lb, } s.ListenAndServe()What if we want to handle retries and replay the request in case of errors? buffer handler will help:
import ( "net/http" "github.com/vulcand/oxy/v2/forward" "github.com/vulcand/oxy/v2/buffer" "github.com/vulcand/oxy/v2/roundrobin" ) // Forwards incoming requests to whatever location URL points to, adds proper forwarding headers fwd := forward.New(false) lb, _ := roundrobin.New(fwd) // buffer will read the request body and will replay the request again in case if forward returned status // corresponding to nework error (e.g. Gateway Timeout) buffer, _ := buffer.New(lb, buffer.Retry(`IsNetworkError() && Attempts() < 2`)) lb.UpsertServer(url1) lb.UpsertServer(url2) // that's it! our reverse proxy is ready! s := &http.Server{ Addr: ":8080", Handler: buffer, } s.ListenAndServe()
