new: implemented update.check module (closes #172)

modules/update.go

@@ -0,0 +1,96 @@
+package modules
+
+import (
+	"context"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/bettercap/bettercap/core"
+	"github.com/bettercap/bettercap/log"
+	"github.com/bettercap/bettercap/session"
+
+	"github.com/google/go-github/github"
+)
+
+type UpdateModule struct {
+	session.SessionModule
+	client *github.Client
+}
+
+func NewUpdateModule(s *session.Session) *UpdateModule {
+	u := &UpdateModule{
+		SessionModule: session.NewSessionModule("update", s),
+		client:        github.NewClient(nil),
+	}
+
+	u.AddHandler(session.NewModuleHandler("update.check on", "",
+		"Check latest available stable version and compare it with the one being used.",
+		func(args []string) error {
+			return u.Start()
+		}))
+
+	return u
+}
+
+func (u *UpdateModule) Name() string {
+	return "update"
+}
+
+func (u *UpdateModule) Description() string {
+	return "A module to check for bettercap's updates."
+}
+
+func (u *UpdateModule) Author() string {
+	return "Simone Margaritelli <evilsocket@protonmail.com>"
+}
+
+func (u *UpdateModule) Configure() error {
+	return nil
+}
+
+func (u *UpdateModule) Stop() error {
+	return nil
+}
+
+func (u *UpdateModule) versionToNum(ver string) float64 {
+	if ver[0] == 'v' {
+		ver = ver[1:]
+	}
+
+	n := 0.0
+	parts := strings.Split(ver, ".")
+	nparts := len(parts)
+
+	// reverse
+	for i := nparts/2 - 1; i >= 0; i-- {
+		opp := nparts - 1 - i
+		parts[i], parts[opp] = parts[opp], parts[i]
+	}
+
+	for i, e := range parts {
+		ev, _ := strconv.Atoi(e)
+		n += float64(ev) * math.Pow10(i)
+	}
+
+	return n
+}
+
+func (u *UpdateModule) Start() error {
+	return u.SetRunning(true, func() {
+		defer u.SetRunning(false, nil)
+
+		log.Info("Checking latest stable release ...")
+
+		if releases, _, err := u.client.Repositories.ListReleases(context.Background(), "bettercap", "bettercap", nil); err == nil {
+			latest := releases[0]
+			if u.versionToNum(core.Version) < u.versionToNum(*latest.TagName) {
+				u.Session.Events.Add("update.available", latest)
+			} else {
+				log.Info("You are running %s which is the latest stable version.", core.Bold(core.Version))
+			}
+		} else {
+			log.Error("Error while fetching latest release info from GitHub: %s", err)
+		}
+	})
+}