Set slack token as flag or env variable

Fixes #133

config/config.go

@@ -39,10 +39,6 @@ func NewConfig(filepath string) (*Config, error) {
 		return &cfg, fmt.Errorf("the slack-term config file isn't valid json: %v", err)
 	}
 
-	if cfg.SlackToken == "" {
-		return &cfg, errors.New("couldn't find 'slack_token' parameter")
-	}
-
 	if cfg.SidebarWidth < 1 || cfg.SidebarWidth > 11 {
 		return &cfg, errors.New("please specify the 'sidebar_width' between 1 and 11")
 	}

context/context.go

@@ -3,6 +3,7 @@ package context
 import (
 	"net/http"
 	_ "net/http/pprof"
+	"os"
 
 	"github.com/0xAX/notificator"
 	"github.com/erroneousboat/termui"
@@ -32,7 +33,7 @@ type AppContext struct {
 
 // CreateAppContext creates an application context which can be passed
 // and referenced througout the application
-func CreateAppContext(flgConfig string, flgDebug bool) (*AppContext, error) {
+func CreateAppContext(flgConfig string, flgToken string, flgDebug bool) (*AppContext, error) {
 	if flgDebug {
 		go func() {
 			http.ListenAndServe(":6060", nil)
@@ -48,6 +49,16 @@ func CreateAppContext(flgConfig string, flgDebug bool) (*AppContext, error) {
 		return nil, err
 	}
 
+	// When slack token isn't set in the config file, we'll check
+	// the command-line flag or the environment variable
+	if config.SlackToken == "" {
+		if flgToken != "" {
+			config.SlackToken = flgToken
+		} else {
+			config.SlackToken = os.Getenv("SLACK_TOKEN")
+		}
+	}
+
 	// Create Service
 	svc, err := service.NewSlackService(config)
 	if err != nil {

main.go

@@ -36,6 +36,7 @@ GLOBAL OPTIONS:
 
 var (
 	flgConfig string
+	flgToken  string
 	flgDebug  bool
 	flgUsage  bool
 )
@@ -55,6 +56,13 @@ func init() {
 		"location of config file",
 	)
 
+	flag.StringVar(
+		&flgToken,
+		"token",
+		"",
+		"the slack token",
+	)
+
 	flag.BoolVar(
 		&flgDebug,
 		"debug",
@@ -87,7 +95,7 @@ func main() {
 	termui.DefaultEvtStream = customEvtStream
 
 	// Create context
-	ctx, err := context.CreateAppContext(flgConfig, flgDebug)
+	ctx, err := context.CreateAppContext(flgConfig, flgToken, flgDebug)
 	if err != nil {
 		termbox.Close()
 		log.Println(err)

service/slack.go

@@ -47,7 +47,7 @@ func NewSlackService(config *config.Config) (*SlackService, error) {
 	// arrives
 	authTest, err := svc.Client.AuthTest()
 	if err != nil {
-		return nil, errors.New("not able to authorize client, check your connection and or slack-token")
+		return nil, errors.New("not able to authorize client, check your connection and if your slack-token is set correctly")
 	}
 	svc.CurrentUserID = authTest.UserID