refactor: improve error interceptor

internal/middleware/middleware.go

@@ -17,7 +17,6 @@ limitations under the License.
 */
 import (
 	"encoding/base64"
-	"encoding/json"
 	"github.com/jkaninda/goma-gateway/pkg/logger"
 	"io"
 	"net/http"
@@ -38,48 +37,23 @@ func (jwtAuth JwtAuth) AuthMiddleware(next http.Handler) http.Handler {
 				if allowedOrigin(jwtAuth.Origins, r.Header.Get("Origin")) {
 					w.Header().Set("Access-Control-Allow-Origin", r.Header.Get("Origin"))
 				}
-				w.WriteHeader(http.StatusUnauthorized)
-				err := json.NewEncoder(w).Encode(ProxyResponseError{
-					Message: http.StatusText(http.StatusUnauthorized),
-					Code:    http.StatusUnauthorized,
-					Success: false,
-				})
-				if err != nil {
-					return
-				}
+				RespondWithError(w, http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized), jwtAuth.ErrorInterceptor)
 				return
+
 			}
 		}
 		//token := r.Header.Get("Authorization")
 		authURL, err := url.Parse(jwtAuth.AuthURL)
 		if err != nil {
 			logger.Error("Error parsing auth URL: %v", err)
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusInternalServerError)
-			err = json.NewEncoder(w).Encode(ProxyResponseError{
-				Message: "Internal Server Error",
-				Code:    http.StatusInternalServerError,
-				Success: false,
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError), jwtAuth.ErrorInterceptor)
 			return
 		}
 		// Create a new request for /authentication
 		authReq, err := http.NewRequest("GET", authURL.String(), nil)
 		if err != nil {
 			logger.Error("Proxy error creating authentication request: %v", err)
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusInternalServerError)
-			err = json.NewEncoder(w).Encode(ProxyResponseError{
-				Message: "Internal Server Error",
-				Code:    http.StatusInternalServerError,
-				Success: false,
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError), jwtAuth.ErrorInterceptor)
 			return
 		}
 		logger.Trace("JWT Auth response headers: %v", authReq.Header)
@@ -99,16 +73,7 @@ func (jwtAuth JwtAuth) AuthMiddleware(next http.Handler) http.Handler {
 		if err != nil || authResp.StatusCode != http.StatusOK {
 			logger.Debug("%s %s %s %s", r.Method, getRealIP(r), r.URL, r.UserAgent())
 			logger.Debug("Proxy authentication error")
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusUnauthorized)
-			err = json.NewEncoder(w).Encode(ProxyResponseError{
-				Message: "Unauthorized",
-				Code:    http.StatusUnauthorized,
-				Success: false,
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized), jwtAuth.ErrorInterceptor)
 			return
 		}
 		defer func(Body io.ReadCloser) {
@@ -146,31 +111,14 @@ func (basicAuth AuthBasic) AuthMiddleware(next http.Handler) http.Handler {
 		if authHeader == "" {
 			logger.Debug("Proxy error, missing Authorization header")
 			w.Header().Set("WWW-Authenticate", `Basic realm="Restricted"`)
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusUnauthorized)
-			err := json.NewEncoder(w).Encode(ProxyResponseError{
-				Success: false,
-				Code:    http.StatusUnauthorized,
-				Message: http.StatusText(http.StatusUnauthorized),
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized), basicAuth.ErrorInterceptor)
 			return
 		}
 		// Check if the Authorization header contains "Basic" scheme
 		if !strings.HasPrefix(authHeader, "Basic ") {
 			logger.Error("Proxy error, missing Basic Authorization header")
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusUnauthorized)
-			err := json.NewEncoder(w).Encode(ProxyResponseError{
-				Success: false,
-				Code:    http.StatusUnauthorized,
-				Message: http.StatusText(http.StatusUnauthorized),
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized), basicAuth.ErrorInterceptor)
+
 			return
 		}
 
@@ -178,16 +126,7 @@ func (basicAuth AuthBasic) AuthMiddleware(next http.Handler) http.Handler {
 		payload, err := base64.StdEncoding.DecodeString(authHeader[len("Basic "):])
 		if err != nil {
 			logger.Debug("Proxy error, missing Basic Authorization header")
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusUnauthorized)
-			err := json.NewEncoder(w).Encode(ProxyResponseError{
-				Success: false,
-				Code:    http.StatusUnauthorized,
-				Message: http.StatusText(http.StatusUnauthorized),
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized), basicAuth.ErrorInterceptor)
 			return
 		}
 
@@ -195,16 +134,7 @@ func (basicAuth AuthBasic) AuthMiddleware(next http.Handler) http.Handler {
 		pair := strings.SplitN(string(payload), ":", 2)
 		if len(pair) != 2 || pair[0] != basicAuth.Username || pair[1] != basicAuth.Password {
 			w.Header().Set("WWW-Authenticate", `Basic realm="Restricted"`)
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusUnauthorized)
-			err := json.NewEncoder(w).Encode(ProxyResponseError{
-				Success: false,
-				Code:    http.StatusUnauthorized,
-				Message: http.StatusText(http.StatusUnauthorized),
-			})
-			if err != nil {
-				return
-			}
+			RespondWithError(w, http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized), basicAuth.ErrorInterceptor)
 			return
 		}