Add debug tool to image

cmd/dbg/main.go

@@ -0,0 +1,203 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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 main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"github.com/spf13/cobra"
+	"k8s.io/ingress-nginx/internal/nginx"
+	"os"
+)
+
+const (
+	backendsPath = "/configuration/backends"
+	generalPath  = "/configuration/general"
+)
+
+func main() {
+	rootCmd := &cobra.Command{
+		Use:   "dbg",
+		Short: "dbg is a tool for quickly inspecting the state of the nginx instance",
+	}
+
+	backendsCmd := &cobra.Command{
+		Use:   "backends",
+		Short: "Inspect the dynamically-loaded backends information",
+	}
+	rootCmd.AddCommand(backendsCmd)
+
+	backendsAllCmd := &cobra.Command{
+		Use:   "all",
+		Short: "Output the all dynamic backend information as a JSON array",
+		Run: func(cmd *cobra.Command, args []string) {
+			backendsAll()
+		},
+	}
+	backendsCmd.AddCommand(backendsAllCmd)
+
+	backendsListCmd := &cobra.Command{
+		Use:   "list",
+		Short: "Output a newline-separated list of the backend names",
+		Run: func(cmd *cobra.Command, args []string) {
+			backendsList()
+		},
+	}
+	backendsCmd.AddCommand(backendsListCmd)
+
+	backendsGetCmd := &cobra.Command{
+		Use:   "get [backend name]",
+		Short: "Output the backend information only for the backend that has this name",
+		Args:  cobra.ExactArgs(1),
+		Run: func(cmd *cobra.Command, args []string) {
+			backendsGet(args[0])
+		},
+	}
+	backendsCmd.AddCommand(backendsGetCmd)
+
+	generalCmd := &cobra.Command{
+		Use:   "general",
+		Short: "Output the general dynamic lua state",
+		Run: func(cmd *cobra.Command, args []string) {
+			general()
+		},
+	}
+	rootCmd.AddCommand(generalCmd)
+
+	confCmd := &cobra.Command{
+		Use:   "conf",
+		Short: "Dump the contents of /etc/nginx/nginx.conf",
+		Run: func(cmd *cobra.Command, args []string) {
+			readNginxConf()
+		},
+	}
+	rootCmd.AddCommand(confCmd)
+
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+}
+
+func backendsAll() {
+	statusCode, body, requestErr := nginx.NewGetStatusRequest(backendsPath)
+	if requestErr != nil {
+		fmt.Println(requestErr)
+		return
+	}
+	if statusCode != 200 {
+		fmt.Printf("Nginx returned code %v", statusCode)
+		return
+	}
+
+	var prettyBuffer bytes.Buffer
+	indentErr := json.Indent(&prettyBuffer, body, "", "  ")
+	if indentErr != nil {
+		fmt.Println(indentErr)
+		return
+	}
+
+	fmt.Println(string(prettyBuffer.Bytes()))
+}
+
+func backendsList() {
+	statusCode, body, requestErr := nginx.NewGetStatusRequest(backendsPath)
+	if requestErr != nil {
+		fmt.Println(requestErr)
+		return
+	}
+	if statusCode != 200 {
+		fmt.Printf("Nginx returned code %v", statusCode)
+		return
+	}
+
+	var f interface{}
+	unmarshalErr := json.Unmarshal(body, &f)
+	if unmarshalErr != nil {
+		fmt.Println(unmarshalErr)
+		return
+	}
+	backends := f.([]interface{})
+
+	for _, backendi := range backends {
+		backend := backendi.(map[string]interface{})
+		fmt.Println(backend["name"].(string))
+	}
+}
+
+func backendsGet(name string) {
+	statusCode, body, requestErr := nginx.NewGetStatusRequest(backendsPath)
+	if requestErr != nil {
+		fmt.Println(requestErr)
+		return
+	}
+	if statusCode != 200 {
+		fmt.Printf("Nginx returned code %v", statusCode)
+		return
+	}
+
+	var f interface{}
+	unmarshalErr := json.Unmarshal(body, &f)
+	if unmarshalErr != nil {
+		fmt.Println(unmarshalErr)
+		return
+	}
+	backends := f.([]interface{})
+
+	for _, backendi := range backends {
+		backend := backendi.(map[string]interface{})
+		if backend["name"].(string) == name {
+			printed, _ := json.MarshalIndent(backend, "", "  ")
+			fmt.Println(string(printed))
+			return
+		}
+	}
+	fmt.Println("A backend of this name was not found.")
+}
+
+func general() {
+	statusCode, body, requestErr := nginx.NewGetStatusRequest(generalPath)
+	if requestErr != nil {
+		fmt.Println(requestErr)
+		return
+	}
+	if statusCode != 200 {
+		fmt.Printf("Nginx returned code %v", statusCode)
+		return
+	}
+
+	var prettyBuffer bytes.Buffer
+	indentErr := json.Indent(&prettyBuffer, body, "", "  ")
+	if indentErr != nil {
+		fmt.Println(indentErr)
+		return
+	}
+
+	fmt.Println(string(prettyBuffer.Bytes()))
+}
+
+func readNginxConf() {
+	conf, err := nginx.ReadNginxConf()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(conf)
+}