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

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

pkg/cmd/hgctl/configCmd.go

@@ -0,0 +1,79 @@
+// 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 (
+	"fmt"
+
+	"github.com/alibaba/higress/pkg/cmd/options"
+	"github.com/spf13/cobra"
+	cmdutil "k8s.io/kubectl/pkg/cmd/util"
+)
+
+func newConfigCommand() *cobra.Command {
+	cfgCommand := &cobra.Command{
+		Use:     "gateway-config",
+		Aliases: []string{"gc"},
+		Short:   "Retrieve Higress Gateway configuration.",
+		Long:    "Retrieve information about Higress Gateway Configuration.",
+	}
+
+	cfgCommand.AddCommand(allConfigCmd())
+	cfgCommand.AddCommand(bootstrapConfigCmd())
+	cfgCommand.AddCommand(clusterConfigCmd())
+	cfgCommand.AddCommand(endpointConfigCmd())
+	cfgCommand.AddCommand(listenerConfigCmd())
+	cfgCommand.AddCommand(routeConfigCmd())
+
+	flags := cfgCommand.Flags()
+	options.AddKubeConfigFlags(flags)
+
+	cfgCommand.PersistentFlags().StringVarP(&output, "output", "o", "json", "One of 'yaml' or 'json'")
+	cfgCommand.PersistentFlags().StringVarP(&podNamespace, "namespace", "n", "higress-system", "Namespace where envoy proxy pod are installed.")
+
+	return cfgCommand
+}
+
+func allConfigCmd() *cobra.Command {
+	configCmd := &cobra.Command{
+		Use:   "all <pod-name>",
+		Short: "Retrieves all Envoy xDS resources from the specified Higress Gateway Pod",
+		Long:  `Retrieves information about all Envoy xDS resources from the specified Higress Gateway Pod`,
+		Example: `  # Retrieve summary about all configuration for a given pod from Envoy.
+  hgctl gateway-config all <pod-name> -n <pod-namespace>
+
+  # Retrieve full configuration dump as YAML
+  hgctl gateway-config all <pod-name> -n <pod-namespace> -o yaml
+
+  # Retrieve full configuration dump with short syntax
+  hgctl gc all <pod-name> -n <pod-namespace>
+`,
+		Run: func(c *cobra.Command, args []string) {
+			cmdutil.CheckErr(runAllConfig(c, args))
+		},
+	}
+
+	return configCmd
+}
+
+func runAllConfig(c *cobra.Command, args []string) error {
+	configDump, err := retrieveConfigDump(args, true)
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintln(c.OutOrStdout(), string(configDump))
+	return err
+}