Connected clients admin API (#217)

* Add support for ending the inbound stream. Closes #191

* Add a simple success response to API requests

* Connected clients API with geo details

* Post-rebase cleanup

* Make setting and reading geo details separate operations to unblock and speed up

* Rename file

* Fire geoip api call behind goroutine

* Add comment

* Post-rebase fixes

* Add support for the MaxMind GeoLite2 GeoIP database

utils/clientId.go

@@ -1,25 +1,41 @@
 package utils
 
 import (
+	"crypto/md5"
+	"encoding/hex"
+	"net"
 	"net/http"
 	"strings"
+
+	log "github.com/sirupsen/logrus"
 )
 
 //GenerateClientIDFromRequest generates a client id from the provided request
 func GenerateClientIDFromRequest(req *http.Request) string {
-	var clientID string
+	ipAddress := GetIPAddressFromRequest(req)
+	ipAddressComponents := strings.Split(ipAddress, ":")
+	ipAddressComponents[len(ipAddressComponents)-1] = ""
+	clientID := strings.Join(ipAddressComponents, ":") + req.UserAgent()
 
+	// Create a MD5 hash of this ip + useragent
+	hasher := md5.New()
+	hasher.Write([]byte(clientID))
+	return hex.EncodeToString(hasher.Sum(nil))
+}
+
+// GetIPAddressFromRequest returns the IP address from a http request
+func GetIPAddressFromRequest(req *http.Request) string {
+	ipAddressString := req.RemoteAddr
 	xForwardedFor := req.Header.Get("X-FORWARDED-FOR")
 	if xForwardedFor != "" {
-		clientID = xForwardedFor
-	} else {
-		ipAddressString := req.RemoteAddr
-		ipAddressComponents := strings.Split(ipAddressString, ":")
-		ipAddressComponents[len(ipAddressComponents)-1] = ""
-		clientID = strings.Join(ipAddressComponents, ":")
+		ipAddressString = xForwardedFor
 	}
 
-	// fmt.Println("IP address determined to be", ipAddress)
+	ip, _, err := net.SplitHostPort(ipAddressString)
+	if err != nil {
+		log.Errorln(err)
+		return ""
+	}
 
-	return clientID + req.UserAgent()
+	return ip
 }