refactored config, added cli options

* config global state removed from the config module
* config global state now resides in main, TODO to remove it
* config now creates a default if none are found
* added command line option for specifying the config file
* added command line option to specify the log level
* config directory now looks in user dir, in a platform agnostic way.
ex: on linux, will typically look in `~/.config/my5g/RANTester` for file
`config.yml`
* updated go.mod to use go v1.16
* embedded default config file data
* errors are now bubbled up appropriately
* depends on #33

cmd/my5g-RANTester/commands.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"github.com/urfave/cli/v2"
+	"my5G-RANTester/config"
 )
 
 const (
@@ -23,6 +24,14 @@ const (
 func setupCommands(a *cli.App) {
 	var commands []*cli.Command
 
+	// TODO: this code is coupled to the ./config module.
+	// this is here because config data is used inside of the test functions.
+	if fixme, err := config.Load(); err != nil {
+		panic(err)
+	} else {
+		cfg = fixme
+	}
+
 	loadTestFlags := []cli.Flag{
 		&cli.IntFlag{Name: argNumUE, Value: argNumUEDefault, Aliases: []string{"n"}},
 	}

cmd/my5g-RANTester/main.go

@@ -14,12 +14,11 @@ const (
 )
 
 func main() {
-	initLogger()
+	app := &cli.App{Before: runAllActions}
 
+	initLogger()
 	log.Infof(fmtMsgVersion, version)
-
-	app := &cli.App{}
-
+	setupOptions(app)
 	setupCommands(app)
 
 	if err := app.Run(os.Args); err != nil {
@@ -32,8 +31,22 @@ func initLogger() {
 	// Can be any io.Writer, see below for File example
 	log.SetOutput(os.Stdout)
 
-	// Only log the warning severity or above.
-	log.SetLevel(log.WarnLevel)
+	log.SetLevel(0)
 
 	spew.Config.Indent = "\t"
 }
+
+func runAllActions(c *cli.Context) (err error) {
+	for _, fn := range []func(c *cli.Context) error{
+		showUsageString,
+		setLogLevel,
+		setConfigFile,
+	} {
+		err = fn(c)
+		if err != nil {
+			break
+		}
+	}
+
+	return err
+}

cmd/my5g-RANTester/options.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"errors"
+	log "github.com/sirupsen/logrus"
+	"github.com/urfave/cli/v2"
+	"my5G-RANTester/config"
+)
+
+const (
+	optLogLevel        = "loglevel"
+	optLogLevelAlias1  = "l"
+	optLogLevelUsage   = "set the log level of the app, (6 is most verbose)"
+	optLogLevelDefault = log.InfoLevel
+
+	optConfig        = "config"
+	optConfigAlias   = "c"
+	optConfigUsage   = "set the config file to use"
+	optConfigDefault = ""
+)
+
+// TODO: remove this ugly global variable *hisssss*
+var cfg *config.Config
+
+func setupOptions(a *cli.App) {
+	a.Flags = []cli.Flag{
+		&cli.IntFlag{
+			Name:    optLogLevel,
+			Aliases: []string{optLogLevelAlias1},
+			Usage:   optLogLevelUsage,
+			Value:   int(optLogLevelDefault),
+		},
+		&cli.StringFlag{
+			Name:    optConfig,
+			Aliases: []string{optConfigAlias},
+			Usage:   optConfigUsage,
+			Value:   optConfigDefault,
+		},
+	}
+}
+
+func showUsageString(c *cli.Context) error {
+	if c.Args().Len() == 0 {
+		_ = cli.ShowAppHelp(c)
+
+		return errors.New("no commands specified, stopping")
+	}
+
+	return nil
+}
+
+func setLogLevel(c *cli.Context) error {
+	ll := c.Int(optLogLevel)
+
+	log.SetLevel(log.Level(ll))
+
+	if ll != int(optLogLevelDefault) {
+		log.Debugf("setting log level to %v", log.Level(ll))
+	}
+
+	return nil
+}
+
+func setConfigFile(c *cli.Context) error {
+	path := c.String(optConfig)
+
+	loaded, err := config.Load(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	log.Debug("config loaded successfully")
+	cfg = loaded
+
+	return nil
+}

cmd/my5g-RANTester/test.go

@@ -4,8 +4,6 @@ import (
 	"fmt"
 
 	log "github.com/sirupsen/logrus"
-
-	"my5G-RANTester/config"
 )
 
 func testLogCommonInfo(name string, numUE int) {
@@ -18,8 +16,6 @@ func testLogCommonInfo(name string, numUE int) {
 		fmtAMFInfo     = "AMF IP/Port: " + fmtIPPort
 	)
 
-	cfg := config.Data
-
 	log.Info(logSep)
 
 	msgStartTest := fmt.Sprintf(fmtStartTest, name)

cmd/my5g-RANTester/test_gnb.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"github.com/urfave/cli/v2"
-
 	"my5G-RANTester/internal/templates"
 )
 
@@ -13,7 +12,5 @@ func testGNB(_ *cli.Context) error {
 
 	testLogCommonInfo(name, argNumUEDefault)
 
-	templates.TestAttachGnbWithConfiguration()
-
-	return nil
+	return templates.TestAttachGnbWithConfiguration(*cfg)
 }

cmd/my5g-RANTester/test_register_multi_ue.go

@@ -3,7 +3,6 @@ package main
 import (
 	log "github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
-
 	"my5G-RANTester/internal/templates"
 )
 
@@ -21,7 +20,6 @@ func testRegisterMultiUE(c *cli.Context) error {
 	numUE := c.Int(argNumUE)
 
 	testLogCommonInfo(name, numUE)
-	templates.TestMultiUesInQueue(numUE)
 
-	return nil
+	return templates.TestMultiUesInQueue(*cfg, numUE)
 }

cmd/my5g-RANTester/test_ue.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"github.com/urfave/cli/v2"
-
 	"my5G-RANTester/internal/templates"
 )
 
@@ -13,7 +12,5 @@ func testUE(_ *cli.Context) error {
 
 	testLogCommonInfo(name, argNumUEDefault)
 
-	templates.TestAttachUeWithConfiguration()
-
-	return nil
+	return templates.TestAttachUeWithConfiguration(*cfg)
 }

config/config.go

@@ -1,96 +1,44 @@
 package config
 
-import (
-	log "github.com/sirupsen/logrus"
-	"gopkg.in/yaml.v2"
-	"io/ioutil"
-	"path"
-	"path/filepath"
-	"runtime"
-)
-
-// Conf: Used for access to configuration
-var Data = getConfig()
-
 type Config struct {
 	GNodeB struct {
 		ControlIF struct {
-			Ip   string `yaml: "ip"`
-			Port int    `yaml: "port"`
-		} `yaml: "controlif"`
+			Ip   string `yaml:"ip"`
+			Port int    `yaml:"port"`
+		} `yaml:"controlif"`
 		DataIF struct {
-			Ip   string `yaml: "ip"`
-			Port int    `yaml: "port"`
-		} `yaml: "dataif"`
+			Ip   string `yaml:"ip"`
+			Port int    `yaml:"port"`
+		} `yaml:"dataif"`
 		PlmnList struct {
-			Mcc   string `yaml: "mmc"`
-			Mnc   string `yaml: "mnc"`
-			Tac   string `yaml: "tac"`
-			GnbId string `yaml: "gnbid"`
-		} `yaml: "plmnlist"`
+			Mcc   string `yaml:"mmc"`
+			Mnc   string `yaml:"mnc"`
+			Tac   string `yaml:"tac"`
+			GnbId string `yaml:"gnbid"`
+		} `yaml:"plmnlist"`
 		SliceSupportList struct {
-			Sst string `yaml: "sst"`
-			Sd  string `yaml: "sd"`
-		} `yaml: "slicesupportlist"`
+			Sst string `yaml:"sst"`
+			Sd  string `yaml:"sd"`
+		} `yaml:"slicesupportlist"`
 	} `yaml:"gnodeb"`
 	Ue struct {
-		Msin  string `yaml: "msin"`
-		Key   string `yaml: "key"`
-		Opc   string `yaml: "opc"`
-		Amf   string `yaml: "amf"`
-		Sqn   string `yaml: "sqn"`
+		Msin  string `yaml:"msin"`
+		Key   string `yaml:"key"`
+		Opc   string `yaml:"opc"`
+		Amf   string `yaml:"amf"`
+		Sqn   string `yaml:"sqn"`
 		Hplmn struct {
-			Mcc string `yaml: "mcc"`
-			Mnc string `yaml: "mnc"`
-		} `yaml: "hplmn"`
+			Mcc string `yaml:"mcc"`
+			Mnc string `yaml:"mnc"`
+		} `yaml:"hplmn"`
 		Snssai struct {
-			Sst int    `yaml: "sst"`
-			Sd  string `yaml: "sd"`
-		} `yaml: "snssai"`
+			Sst int    `yaml:"sst"`
+			Sd  string `yaml:"sd"`
+		} `yaml:"snssai"`
 	} `yaml:"ue"`
 	AMF struct {
-		Ip   string `yaml: "ip"`
-		Port int    `yaml: "port"`
-		Name string `yaml: "name"`
+		Ip   string `yaml:"ip"`
+		Port int    `yaml:"port"`
+		Name string `yaml:"name"`
 	} `yaml:"amfif"`
 }
-
-func RootDir() string {
-	_, b, _, _ := runtime.Caller(0)
-	d := path.Join(path.Dir(b))
-	return filepath.Dir(d)
-}
-
-func getConfig() Config {
-	var cfg = Config{}
-	Ddir := RootDir()
-	configPath, err := filepath.Abs(Ddir + "/config/config.yml")
-	log.Debug(configPath)
-	if err != nil {
-		log.Fatal("Could not find config in: ", configPath)
-	}
-	file, err := ioutil.ReadFile(configPath)
-	err = yaml.Unmarshal([]byte(file), &cfg)
-	if err != nil {
-		log.Fatal("Could not read file in: ", configPath)
-	}
-
-	return cfg
-}
-
-func GetConfig() (Config, error) {
-	var cfg = Config{}
-	Ddir := RootDir()
-	configPath, err := filepath.Abs(Ddir + "/config/config.yml")
-	log.Debug(configPath)
-	if err != nil {
-		return Config{}, nil
-	}
-	file, err := ioutil.ReadFile(configPath)
-	err = yaml.Unmarshal([]byte(file), &cfg)
-	if err != nil {
-		return Config{}, nil
-	}
-
-	return cfg, nil
-}