Files
remark42/app/rest/middleware.go
T
2017-12-20 15:29:54 -06:00

105 lines
2.6 KiB
Go

package rest
import (
"log"
"net/http"
"os"
"strings"
"time"
"github.com/didip/tollbooth"
"github.com/go-chi/render"
)
var org = "Umputun"
// JSON is a map alias, just for convenience
type JSON map[string]interface{}
// Limiter middleware defines max recs/sec for given client. Client detected as a combination
// of source IP, auth key and user agent. Requests rejected with 429 status code.
func Limiter(recSec int, excludeIps ...string) func(http.Handler) http.Handler {
return func(h http.Handler) http.Handler {
l := tollbooth.NewLimiter(int64(recSec), time.Second)
fn := func(w http.ResponseWriter, r *http.Request) {
for _, exclIP := range excludeIps {
if strings.HasPrefix(r.RemoteAddr, exclIP) {
h.ServeHTTP(w, r)
return
}
}
keys := []string{
r.Header.Get("Authorization"),
r.Header.Get("X-Forwarded-For"),
r.Header.Get("X-Real-IP"),
r.Header.Get("RemoteAddr"),
r.Header.Get("User-Agent"),
}
if httpError := tollbooth.LimitByKeys(l, keys); httpError != nil {
render.Status(r, httpError.StatusCode)
render.JSON(w, r, JSON{"error": httpError.Message})
return
}
h.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
}
// AppInfo adds custom app-info to header
func AppInfo(app string, version string) func(http.Handler) http.Handler {
f := func(h http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Org", org)
w.Header().Set("App-Name", app)
w.Header().Set("App-Version", version)
if mhost := os.Getenv("MHOST"); mhost != "" {
w.Header().Set("Host", mhost)
}
h.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
return f
}
// Ping middleware response with pong. Stops chain if ping request detected
func Ping(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
if r.Method == "GET" && strings.HasSuffix(strings.ToLower(r.URL.Path), "/ping") {
w.Header().Set("Content-Type", "text/plain")
w.WriteHeader(http.StatusOK)
if _, err := w.Write([]byte("pong")); err != nil {
log.Printf("[WARN] can't send pong, %s", err)
}
return
}
next.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
// Recoverer is a middleware that recovers from panics, logs the panic and returns a HTTP 500 status if possible.
func Recoverer(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
defer func() {
if rvr := recover(); rvr != nil {
log.Printf("[ERROR] request panic, %v", rvr)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
}()
next.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}