yyyar#29 Refactored code to support multiple config locations; Added …

…better arguments parsing; Added file and basic Consul config pullers

Makefile

@@ -65,6 +65,7 @@ deps: clean-deps
 	github.com/elgs/gojq \
 	github.com/gin-gonic/gin \
 	github.com/hashicorp/consul/api \
+	github.com/spf13/cobra \
 	github.com/laher/goxc
 
 clean-dist:

config/gobetween.json

@@ -0,0 +1,16 @@
+{
+    "servers": {
+        "sample":{
+            "bind":"localhost:3000",
+            "healthcheck": {
+                "kind": "ping",
+                "interval": "2s",
+                "timeout": "1s"
+            },
+            "discovery": {
+                "kind": "static",
+                "static_list": ["localhost:8000 weight=1"]
+            }
+        }
+    }
+}

src/api/root.go

@@ -25,12 +25,11 @@ func attachRoot(app *gin.RouterGroup) {
 	app.GET("/", func(c *gin.Context) {
 
 		c.IndentedJSON(http.StatusOK, gin.H{
-			"pid":        os.Getpid(),
-			"time":       time.Now(),
-			"startTime":  info.StartTime,
-			"uptime":     time.Now().Sub(info.StartTime).String(),
-			"version":    info.Version,
-			"configPath": info.ConfigPath,
+			"pid":       os.Getpid(),
+			"time":      time.Now(),
+			"startTime": info.StartTime,
+			"uptime":    time.Now().Sub(info.StartTime).String(),
+			"version":   info.Version,
 		})
 	})
 

src/cmd/cmd.go

@@ -0,0 +1,23 @@
+/**
+ * cmd.go - command line runner
+ *
+ * @author Yaroslav Pogrebnyak <[email protected]>
+ */
+package cmd
+
+import (
+	"../config"
+)
+
+/**
+ * App Start function to call after initialization
+ */
+var start func(*config.Config)
+
+/**
+ * Execute processing flags
+ */
+func Execute(f func(*config.Config)) {
+	start = f
+	RootCmd.Execute()
+}

src/cmd/from-consul.go

@@ -0,0 +1,63 @@
+/**
+ * from-consul.go - pull config from consul and run
+ *
+ * @author Yaroslav Pogrebnyak <[email protected]>
+ */
+package cmd
+
+import (
+	"../config"
+	"../utils/codec"
+	consul "github.com/hashicorp/consul/api"
+	"github.com/spf13/cobra"
+	"log"
+)
+
+/* Parsed options */
+var consulHost string
+var consulKey string
+
+/**
+ * Add command
+ */
+func init() {
+
+	FromConsulCmd.Flags().StringVarP(&consulHost, "host", "", "localhost", "Consul host")
+	FromConsulCmd.Flags().StringVarP(&consulKey, "key", "", "gobetween", "Consul Key to pull config from")
+
+	RootCmd.AddCommand(FromConsulCmd)
+}
+
+/**
+ * FromConsul command
+ */
+var FromConsulCmd = &cobra.Command{
+	Use:   "from-consul",
+	Short: "Pull config from Consul",
+	Long:  `Pull config from the Consul Key-Value storage`,
+	Run: func(cmd *cobra.Command, args []string) {
+
+		client, err := consul.NewClient(&consul.Config{
+			Address: consulHost,
+		})
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		pair, _, err := client.KV().Get(consulKey, nil)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		if pair == nil {
+			log.Fatal("Empty value for key " + consulKey)
+		}
+
+		var cfg config.Config
+		if err := codec.Decode(string(pair.Value), &cfg, format); err != nil {
+			log.Fatal(err)
+		}
+
+		start(&cfg)
+	},
+}

src/cmd/from-file.go

@@ -0,0 +1,47 @@
+/**
+ * from-file.go - pull config from file and run
+ *
+ * @author Yaroslav Pogrebnyak <[email protected]>
+ */
+package cmd
+
+import (
+	"../config"
+	"../utils/codec"
+	"github.com/spf13/cobra"
+	"io/ioutil"
+	"log"
+)
+
+/* Parsed options */
+var configPath string
+
+/**
+ * Add Root Command
+ */
+func init() {
+	FromFileCmd.Flags().StringVarP(&configPath, "config", "c", "./gobetween.toml", "Path to configuration file")
+	RootCmd.AddCommand(FromFileCmd)
+}
+
+/**
+ * FromFile Command
+ */
+var FromFileCmd = &cobra.Command{
+	Use:   "from-file",
+	Short: "Use config from file",
+	Run: func(cmd *cobra.Command, args []string) {
+
+		data, err := ioutil.ReadFile(configPath)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		var cfg config.Config
+		if err = codec.Decode(string(data), &cfg, format); err != nil {
+			log.Fatal(err)
+		}
+
+		start(&cfg)
+	},
+}

src/cmd/root.go

@@ -0,0 +1,33 @@
+/**
+ * root.go - root cmd emulates from-file TODO: remove when time will come
+ *
+ * @author Yaroslav Pogrebnyak <[email protected]>
+ */
+package cmd
+
+import (
+	"github.com/spf13/cobra"
+)
+
+/* Persistent parsed options */
+var format string
+
+/**
+ * Add Root Command
+ */
+func init() {
+	RootCmd.Flags().StringVarP(&configPath, "config", "c", "./gobetween.toml", "Path to configuration file")
+	RootCmd.PersistentFlags().StringVarP(&format, "format", "f", "toml", "Configuration file format: toml or json")
+}
+
+/**
+ * Root Command
+ */
+var RootCmd = &cobra.Command{
+	Use:   "gobetween",
+	Short: "Modern & minimalistic load balancer for the Cload era",
+	Run: func(cmd *cobra.Command, args []string) {
+		// TODO: Remove when times will come to break backward-compatibility
+		FromFileCmd.Run(cmd, args)
+	},
+}

src/info/info.go

@@ -5,5 +5,4 @@ import (
 )
 
 var Version string
-var ConfigPath string
 var StartTime time.Time

src/main.go

@@ -2,38 +2,26 @@
  * main.go - entry point
  * @author Yaroslav Pogrebnyak <[email protected]>
  */
-
 package main
 
 import (
 	"./api"
+	"./cmd"
 	"./config"
 	"./info"
 	"./logging"
 	"./manager"
-	"flag"
-	"github.com/BurntSushi/toml"
 	"math/rand"
 	"os"
 	"runtime"
 	"time"
 )
 
 /**
- * Constants
- */
-const (
-	defaultConfigPath = "./gobetween.toml"
-)
-
-/**
- * Version should be set while build
- * using ldflags (see Makefile)
+ * Version should be set while build using ldflags (see Makefile)
  */
 var version string
 
-var configPath string
-
 /**
  * Initialize package
  */
@@ -47,41 +35,30 @@ func init() {
 	// Init random seed
 	rand.Seed(time.Now().UnixNano())
 
-	// Init command-line flags
-	flag.StringVar(&configPath, "c", defaultConfigPath, "Path to config file")
-
-	// Set info to be used in another parts of the program
+	// Save info
 	info.Version = version
-	info.ConfigPath = configPath
 	info.StartTime = time.Now()
+
 }
 
 /**
  * Entry point
  */
 func main() {
 
-	flag.Parse()
-
-	log := logging.For("main")
-	log.Info("gobetween v", version)
-	log.Info("Using config file ", configPath)
-
-	// Parse config
-	var cfg config.Config
-	if _, err := toml.DecodeFile(configPath, &cfg); err != nil {
-		log.Fatal(err)
-	}
+	// Process flags and start
+	cmd.Execute(func(cfg *config.Config) {
 
-	// Configure logging
-	logging.Configure(cfg.Logging.Output, cfg.Logging.Level)
+		// Configure logging
+		logging.Configure(cfg.Logging.Output, cfg.Logging.Level)
 
-	// Start API
-	go api.Start(cfg.Api)
+		// Start API
+		go api.Start((*cfg).Api)
 
-	// Start manager
-	go manager.Initialize(cfg)
+		// Start manager
+		go manager.Initialize(*cfg)
 
-	// block forever
-	<-(chan string)(nil)
+		// block forever
+		<-(chan string)(nil)
+	})
 }

src/utils/codec/codec.go

@@ -0,0 +1,29 @@
+/**
+ * codec.go - decoding utils
+ *
+ * @author Yaroslav Pogrebnyak <[email protected]>
+ */
+package codec
+
+import (
+	"encoding/json"
+	"errors"
+	"github.com/BurntSushi/toml"
+)
+
+/**
+ * Decode data based on format
+ * Currently supported: toml and json
+ */
+func Decode(data string, out interface{}, format string) error {
+
+	switch format {
+	case "toml":
+		_, err := toml.Decode(data, out)
+		return err
+	case "json":
+		return json.Unmarshal([]byte(data), out)
+	default:
+		return errors.New("Unknown format " + format)
+	}
+}