Pull request: all: updater exe name

Merge in DNS/adguard-home from 4219-updater to master

Squashed commit of the following:

commit f569a5f232330b83c234838a5bff8ae5277f152f
Merge: a90b4fa7 3505ce87
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 22:14:50 2022 +0530

    Merge remote-tracking branch 'origin/master' into 4219-updater

    # Conflicts:
    #	CHANGELOG.md

commit a90b4fa7782c5ec4531d8e305c0d448e84898239
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 21:56:17 2022 +0530

    home: imp code

commit da0f96b976e430fffc531072ef3e2384bc8b1f09
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 21:48:40 2022 +0530

    updater: exe name

commit 246dc9ca3b133cbc93ea59edd272674b87ff8de3
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 19:18:02 2022 +0530

    all: imp docs

commit 042382d170c4d68ff67fe5544a75371337529623
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 18:02:25 2022 +0530

    all: updater exe name

commit a180c4673ead66788969865784348634af1a739e
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 17:47:46 2022 +0530

    docs: updater exe name

commit 1a98a6eadbd96add0a488fb8f89fb7d8b0ffb3d0
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 17:40:44 2022 +0530

    all: updater exe name

commit 1b13f5d85550dc71b08fd8e5b4258f8414a38759
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Thu Jul 7 17:14:57 2022 +0530

    all: updater exe name

CHANGELOG.md

@@ -32,6 +32,8 @@ and this project adheres to
 
 ### Fixed
 
+- Updater no longer expects a hardcoded name for  `AdGuardHome` executable
+  ([#4219]).
 - Inconsistent names of runtime clients from hosts files ([#4683]).
 - PTR requests for addresses leased by DHCP will now be resolved into hostnames
   under `dhcp.local_domain_name` ([#4699]).
@@ -39,6 +41,7 @@ and this project adheres to
 
 [#2993]: https://github.com/AdguardTeam/AdGuardHome/issues/2993
 [#3057]: https://github.com/AdguardTeam/AdGuardHome/issues/3057
+[#4219]: https://github.com/AdguardTeam/AdGuardHome/issues/4219
 [#4677]: https://github.com/AdguardTeam/AdGuardHome/issues/4677
 [#4683]: https://github.com/AdguardTeam/AdGuardHome/issues/4683
 [#4699]: https://github.com/AdguardTeam/AdGuardHome/issues/4699

internal/home/controlupdate.go

@@ -7,7 +7,6 @@ import (
 	"net/http"
 	"os"
 	"os/exec"
-	"path/filepath"
 	"runtime"
 	"syscall"
 	"time"
@@ -180,11 +179,10 @@ func finishUpdate(ctx context.Context) {
 	cleanup(ctx)
 	cleanupAlways()
 
-	exeName := "AdGuardHome"
-	if runtime.GOOS == "windows" {
-		exeName = "AdGuardHome.exe"
+	curBinName, err := os.Executable()
+	if err != nil {
+		log.Fatalf("executable path request failed: %s", err)
 	}
-	curBinName := filepath.Join(Context.workDir, exeName)
 
 	if runtime.GOOS == "windows" {
 		if Context.runningAsService {
@@ -192,7 +190,7 @@ func finishUpdate(ctx context.Context) {
 			// we can't restart the service via "kardianos/service" package - it kills the process first
 			// we can't start a new instance - Windows doesn't allow it
 			cmd := exec.Command("cmd", "/c", "net stop AdGuardHome & net start AdGuardHome")
-			err := cmd.Start()
+			err = cmd.Start()
 			if err != nil {
 				log.Fatalf("exec.Command() failed: %s", err)
 			}
@@ -204,14 +202,14 @@ func finishUpdate(ctx context.Context) {
 		cmd.Stdin = os.Stdin
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
-		err := cmd.Start()
+		err = cmd.Start()
 		if err != nil {
 			log.Fatalf("exec.Command() failed: %s", err)
 		}
 		os.Exit(0)
 	} else {
 		log.Info("Restarting: %v", os.Args)
-		err := syscall.Exec(curBinName, os.Args, os.Environ())
+		err = syscall.Exec(curBinName, os.Args, os.Environ())
 		if err != nil {
 			log.Fatalf("syscall.Exec() failed: %s", err)
 		}

internal/updater/updater.go

@@ -111,7 +111,12 @@ func (u *Updater) Update() (err error) {
 	log.Info("updater: updating")
 	defer func() { log.Info("updater: finished; errors: %v", err) }()
 
-	err = u.prepare()
+	execPath, err := os.Executable()
+	if err != nil {
+		return err
+	}
+
+	err = u.prepare(filepath.Base(execPath))
 	if err != nil {
 		return err
 	}
@@ -162,7 +167,8 @@ func (u *Updater) VersionCheckURL() (vcu string) {
 	return u.versionCheckURL
 }
 
-func (u *Updater) prepare() (err error) {
+// prepare fills all necessary fields in Updater object.
+func (u *Updater) prepare(exeName string) (err error) {
 	u.updateDir = filepath.Join(u.workDir, fmt.Sprintf("agh-update-%s", u.newVersion))
 
 	_, pkgNameOnly := filepath.Split(u.packageURL)
@@ -173,13 +179,13 @@ func (u *Updater) prepare() (err error) {
 	u.packageName = filepath.Join(u.updateDir, pkgNameOnly)
 	u.backupDir = filepath.Join(u.workDir, "agh-backup")
 
-	exeName := "AdGuardHome"
+	updateExeName := "AdGuardHome"
 	if u.goos == "windows" {
-		exeName = "AdGuardHome.exe"
+		updateExeName = "AdGuardHome.exe"
 	}
 
 	u.backupExeName = filepath.Join(u.backupDir, exeName)
-	u.updateExeName = filepath.Join(u.updateDir, exeName)
+	u.updateExeName = filepath.Join(u.updateDir, updateExeName)
 
 	log.Debug(
 		"updater: updating from %s to %s using url: %s",
@@ -188,7 +194,6 @@ func (u *Updater) prepare() (err error) {
 		u.packageURL,
 	)
 
-	// TODO(a.garipov): Use os.Args[0] instead?
 	u.currentExeName = filepath.Join(u.workDir, exeName)
 	_, err = os.Stat(u.currentExeName)
 	if err != nil {

internal/updater/updater_test.go

@@ -131,7 +131,7 @@ func TestUpdate(t *testing.T) {
 	u.newVersion = "v0.103.1"
 	u.packageURL = fakeURL.String()
 
-	require.NoError(t, u.prepare())
+	require.NoError(t, u.prepare("AdGuardHome"))
 
 	u.currentExeName = filepath.Join(wd, "AdGuardHome")
 
@@ -209,7 +209,7 @@ func TestUpdateWindows(t *testing.T) {
 	u.newVersion = "v0.103.1"
 	u.packageURL = fakeURL.String()
 
-	require.NoError(t, u.prepare())
+	require.NoError(t, u.prepare("AdGuardHome.exe"))
 
 	u.currentExeName = filepath.Join(wd, "AdGuardHome.exe")