chore(refactor): refactors go code (#2443)

internal/auth/proxy.go

@@ -0,0 +1,58 @@
+package auth
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"net/http"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type contextKey string
+
+const RemoteUser contextKey = "remoteUser"
+
+type User struct {
+	Username string `json:"username"`
+	Email    string `json:"email"`
+	Name     string `json:"name"`
+	Avatar   string `json:"avatar,omitempty"`
+}
+
+func hashEmail(email string) string {
+	email = strings.TrimSpace(email)
+	email = strings.ToLower(email)
+	hash := md5.Sum([]byte(email))
+
+	return hex.EncodeToString(hash[:])
+}
+
+func newUser(username, email, name string) *User {
+	avatar := ""
+	if email != "" {
+		avatar = "https://gravatar.com/avatar/" + hashEmail(email)
+	}
+	return &User{
+		Username: username,
+		Email:    email,
+		Name:     name,
+		Avatar:   avatar,
+	}
+}
+
+func ForwardProxyAuthorizationRequired(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("Remote-Email") == "" {
+			log.Error("Unable to find remote email. Please check your proxy configuration. Expecting header 'Remote-Email'")
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+
+		user := newUser(r.Header.Get("Remote-User"), r.Header.Get("Remote-Email"), r.Header.Get("Remote-Name"))
+
+		ctx := context.WithValue(r.Context(), RemoteUser, user)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}