simple version checker ✌️

Former-commit-id: 077b9c9816211c84adda864a832acf8c1296eeaf

version.go

@@ -0,0 +1,151 @@
+package iris
+
+import (
+	"bufio"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"os"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/hashicorp/go-version"
+	"github.com/kataras/golog"
+)
+
+const (
+	versionURL = "https://raw.githubusercontent.com/kataras/iris/master/VERSION"
+	updateCmd  = "go get -u -f -v github.com/kataras/iris"
+)
+
+var checkVersionOnce = sync.Once{}
+
+// CheckVersion checks for any available updates.
+func CheckVersion() {
+	checkVersionOnce.Do(func() {
+		checkVersion()
+	})
+}
+
+func checkVersion() {
+
+	// open connection and read/write timeouts
+	timeout := time.Duration(10 * time.Second)
+
+	transport := http.Transport{
+		Dial: func(network string, addr string) (net.Conn, error) {
+			conn, err := net.DialTimeout(network, addr, timeout)
+			if err != nil {
+				golog.Debugf("%v", err)
+				return nil, err
+			}
+			conn.SetDeadline(time.Now().Add(timeout)) // skip error
+			return conn, nil
+		},
+	}
+
+	client := http.Client{
+		Transport: &transport,
+	}
+
+	r, err := client.Get(versionURL)
+	if err != nil {
+		golog.Debugf("%v", err)
+		return
+	}
+	defer r.Body.Close()
+
+	if r.StatusCode >= 400 {
+		return
+	}
+
+	b, err := ioutil.ReadAll(r.Body)
+
+	if len(b) == 0 || err != nil {
+		golog.Debugf("%v", err)
+		return
+	}
+
+	var (
+		fetchedVersion = string(b)
+		changelogURL   string
+	)
+
+	// 8.2.1:https://github.com/kataras/iris/blob/master/HISTORY.md#tu-08-august-2017--v821
+	if idx := strings.IndexByte(fetchedVersion, ':'); idx > 0 {
+		changelogURL = fetchedVersion[idx+1:]
+		fetchedVersion = fetchedVersion[0:idx]
+	}
+
+	latestVersion, err := version.NewVersion(fetchedVersion)
+	if err != nil {
+		golog.Debugf("while parsing latest version: %v", err)
+		return
+	}
+
+	currentVersion, err := version.NewVersion(Version)
+	if err != nil {
+		golog.Debugf("while parsing current version: %v", err)
+		return
+	}
+
+	if currentVersion.GreaterThan(latestVersion) {
+		golog.Debugf("current version is greater than latest version, report as bug")
+		return
+	}
+
+	if currentVersion.Equal(latestVersion) {
+		return
+	}
+
+	// currentVersion.LessThan(latestVersion)
+
+	var updaterYesInput = [...]string{"y", "yes"}
+
+	text := "A more recent version has been found[%s > %s].\n"
+
+	if changelogURL != "" {
+		text += "Release notes: %s\n"
+	}
+
+	text += "Update now?[%s]: "
+
+	golog.Warnf(text,
+		latestVersion.String(), currentVersion.String(),
+		changelogURL,
+		updaterYesInput[0]+"/n")
+
+	silent := false
+
+	sc := bufio.NewScanner(os.Stdin)
+
+	shouldUpdate := silent
+
+	if !silent {
+		if sc.Scan() {
+			inputText := sc.Text()
+			for _, s := range updaterYesInput {
+				if inputText == s {
+					shouldUpdate = true
+				}
+			}
+		}
+	}
+
+	if shouldUpdate {
+		goget := strings.Split(updateCmd, " ")
+		// go get -u github.com/:owner/:repo
+		cmd := exec.Command(goget[0], goget[1:]...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stdout
+
+		if err := cmd.Run(); err != nil {
+			golog.Warnf("unexpected message while trying to go get: %v", err)
+			return
+		}
+
+		golog.Infof("Update process finished, current version: %s.\nManual restart is required to apply the changes.\n", latestVersion.String())
+	}
+}