feat: add support for hgctl gateway-config to retrieve higress gateway config (#274)

Signed-off-by: bitliu <bitliu@tencent.com>

pkg/cmd/hgctl/utils.go

@@ -0,0 +1,81 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hgctl
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type envoyConfigType string
+
+var (
+	BootstrapEnvoyConfigType envoyConfigType = "bootstrap"
+	ClusterEnvoyConfigType   envoyConfigType = "cluster"
+	EndpointEnvoyConfigType  envoyConfigType = "endpoint"
+	ListenerEnvoyConfigType  envoyConfigType = "listener"
+	RouteEnvoyConfigType     envoyConfigType = "route"
+	AllEnvoyConfigType       envoyConfigType = "all"
+)
+
+func GetXDSResource(resourceType envoyConfigType, configDump []byte) (any, error) {
+	cd := map[string]any{}
+	if err := json.Unmarshal(configDump, &cd); err != nil {
+		return nil, err
+	}
+	if resourceType == AllEnvoyConfigType {
+		return cd, nil
+	}
+	configs := cd["configs"]
+	globalConfigs := configs.([]any)
+
+	switch resourceType {
+	case BootstrapEnvoyConfigType:
+		for _, config := range globalConfigs {
+			if config.(map[string]interface{})["@type"] == "type.googleapis.com/envoy.admin.v3.BootstrapConfigDump" {
+				return config, nil
+			}
+		}
+	case EndpointEnvoyConfigType:
+		for _, config := range globalConfigs {
+			if config.(map[string]interface{})["@type"] == "type.googleapis.com/envoy.admin.v3.EndpointsConfigDump" {
+				return config, nil
+			}
+		}
+
+	case ClusterEnvoyConfigType:
+		for _, config := range globalConfigs {
+			if config.(map[string]interface{})["@type"] == "type.googleapis.com/envoy.admin.v3.ClustersConfigDump" {
+				return config, nil
+			}
+		}
+	case ListenerEnvoyConfigType:
+		for _, config := range globalConfigs {
+			if config.(map[string]interface{})["@type"] == "type.googleapis.com/envoy.admin.v3.ListenersConfigDump" {
+				return config, nil
+			}
+		}
+	case RouteEnvoyConfigType:
+		for _, config := range globalConfigs {
+			if config.(map[string]interface{})["@type"] == "type.googleapis.com/envoy.admin.v3.RoutesConfigDump" {
+				return config, nil
+			}
+		}
+	default:
+		return nil, fmt.Errorf("unknown resourceType %s", resourceType)
+	}
+
+	return nil, fmt.Errorf("unknown resourceType %s", resourceType)
+}