18F/e-QIP-prototype

package http

import (
    "net/http"
    "strings"

    "github.com/18F/e-QIP-prototype/api"
)

// LoggingHandler is the handler for logging.
type LoggingHandler struct {
    Log api.LogService
}

// Middleware for standard logging.
func (service LoggingHandler) Middleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        service.Log.AddField("ip", ipAddress(r))
        service.Log.Info(api.WebRequest, api.LogFields{
            "method": r.Method,
            "url":    r.URL.String(),
            "remote": r.RemoteAddr,
        })
        next.ServeHTTP(w, r)
    })
}

func ipAddress(r *http.Request) string {
    ip := r.RemoteAddr
    proxies := r.Header.Get(http.CanonicalHeaderKey("x-forwarded-for"))
    if proxies != "" {
        for _, proxy := range strings.Split(proxies, ", ") {
            ip = proxy
        }
    }
    return ip
}