fix: Fix label values query when server.http_path_prefix is set (#15978)

This commit fixes a bug in the query range round tripper. It fixes the detection of the operation when decoding a HTTP request into a queryrange request object by comparing the path suffix rather than the equality of the full path.

Signed-off-by: Christian Haudum <christian.haudum@gmail.com>

pkg/querier/queryrange/roundtrip.go

@@ -506,32 +506,34 @@ func getOperation(path string) string {
 	switch {
 	case strings.HasSuffix(path, "/query_range") || strings.HasSuffix(path, "/prom/query"):
 		return QueryRangeOp
+	case strings.HasSuffix(path, "/query"):
+		return InstantQueryOp
 	case strings.HasSuffix(path, "/series"):
 		return SeriesOp
 	case strings.HasSuffix(path, "/labels") || strings.HasSuffix(path, "/label"):
 		return LabelNamesOp
-	case strings.HasSuffix(path, "/v1/query"):
-		return InstantQueryOp
-	case path == "/loki/api/v1/index/stats":
+	case strings.HasSuffix(path, "/index/stats"):
 		return IndexStatsOp
-	case path == "/loki/api/v1/index/volume":
+	case strings.HasSuffix(path, "/index/volume"):
 		return VolumeOp
-	case path == "/loki/api/v1/index/volume_range":
+	case strings.HasSuffix(path, "/index/volume_range"):
 		return VolumeRangeOp
-	case path == "/loki/api/v1/index/shards":
+	case strings.HasSuffix(path, "/index/shards"):
 		return IndexShardsOp
-	case path == "/loki/api/v1/detected_fields":
+	case strings.HasSuffix(path, "/detected_fields"):
 		return DetectedFieldsOp
+	case strings.HasSuffix(path, "/patterns"):
+		return PatternsQueryOp
+	case strings.HasSuffix(path, "/detected_labels"):
+		return DetectedLabelsOp
 	case strings.HasSuffix(path, "/values"):
-		if strings.HasPrefix(path, "/loki/api/v1/label") || strings.HasPrefix(path, "/api/prom/label") {
+		if strings.Contains(path, "/label") {
 			return LabelNamesOp
 		}
-
-		return DetectedFieldsOp
-	case path == "/loki/api/v1/patterns":
-		return PatternsQueryOp
-	case path == "/loki/api/v1/detected_labels":
-		return DetectedLabelsOp
+		if strings.Contains(path, "/detected_field") {
+			return DetectedFieldsOp
+		}
+		return ""
 	default:
 		return ""
 	}

pkg/querier/queryrange/roundtrip_test.go

@@ -1273,11 +1273,14 @@ func Test_getOperation(t *testing.T) {
 		},
 	}
 
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			got := getOperation(tc.path)
-			assert.Equal(t, tc.expectedOp, got)
-		})
+	for _, pathPrefix := range []string{"", "/proxy"} {
+		for _, tc := range cases {
+			name := tc.name + pathPrefix + tc.path
+			t.Run(name, func(t *testing.T) {
+				got := getOperation(pathPrefix + tc.path)
+				assert.Equal(t, tc.expectedOp, got)
+			})
+		}
 	}
 }