alerts on new nex version (#174)

* alerts on new nex version

nex/nex.go

@@ -58,6 +58,8 @@ var (
 )
 
 func init() {
+	_ = versionCheck()
+
 	ncli.Flag("server", "NATS server urls").Short('s').Envar("NATS_URL").PlaceHolder("URL").StringVar(&Opts.Servers)
 	ncli.Flag("user", "Username or Token").Envar("NATS_USER").PlaceHolder("USER").StringVar(&Opts.Username)
 	ncli.Flag("password", "Password").Envar("NATS_PASSWORD").PlaceHolder("PASSWORD").StringVar(&Opts.Password)

nex/update.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+func versionCheck() error {
+	if VERSION == "development" {
+		return nil
+	}
+
+	res, err := http.Get("https://api.github.com/repos/synadia-io/nex/releases/latest")
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+
+	b, err := io.ReadAll(res.Body)
+	if err != nil {
+		return err
+	}
+
+	payload := make(map[string]interface{})
+	err = json.Unmarshal(b, &payload)
+	if err != nil {
+		return err
+	}
+
+	latestTag, ok := payload["tag_name"].(string)
+	if !ok {
+		return errors.New("error parsing tag_name")
+	}
+
+	if latestTag != VERSION {
+		fmt.Printf(`================================================================
+🎉 There is a newer version [v%s] of the NEX CLI available 🎉
+To update, run:
+     curl -sSf https://nex.synadia.com/install.sh | sh
+================================================================
+
+`,
+			latestTag)
+	}
+
+	return nil
+}