[Chore] Improve auto update mechanism (#1009)

beszel/internal/agent/update.go

@@ -1,56 +1,168 @@
 package agent
 
 import (
-	"beszel"
-	"fmt"
-	"os"
-	"strings"
+    "fmt"
+    "log"
+    "os"
+    "os/exec"
+    "strings"
 
-	"github.com/blang/semver"
-	"github.com/rhysd/go-github-selfupdate/selfupdate"
+    "beszel"
+
+    "github.com/blang/semver"
+    "github.com/rhysd/go-github-selfupdate/selfupdate"
 )
 
-// Update updates beszel-agent to the latest version
-func Update() {
-	var latest *selfupdate.Release
-	var found bool
-	var err error
-	currentVersion := semver.MustParse(beszel.Version)
-	fmt.Println("beszel-agent", currentVersion)
-	fmt.Println("Checking for updates...")
-	updater, _ := selfupdate.NewUpdater(selfupdate.Config{
-		Filters: []string{"beszel-agent"},
-	})
-	latest, found, err = updater.DetectLatest("henrygd/beszel")
-
-	if err != nil {
-		fmt.Println("Error checking for updates:", err)
-		os.Exit(1)
-	}
-
-	if !found {
-		fmt.Println("No updates found")
-		os.Exit(0)
-	}
-
-	fmt.Println("Latest version:", latest.Version)
-
-	if latest.Version.LTE(currentVersion) {
-		fmt.Println("You are up to date")
-		return
-	}
-
-	var binaryPath string
-	fmt.Printf("Updating from %s to %s...\n", currentVersion, latest.Version)
-	binaryPath, err = os.Executable()
-	if err != nil {
-		fmt.Println("Error getting binary path:", err)
-		os.Exit(1)
-	}
-	err = selfupdate.UpdateTo(latest.AssetURL, binaryPath)
-	if err != nil {
-		fmt.Println("Please try rerunning with sudo. Error:", err)
-		os.Exit(1)
-	}
-	fmt.Printf("Successfully updated to %s\n\n%s\n", latest.Version, strings.TrimSpace(latest.ReleaseNotes))
+// restarter knows how to restart the beszel-agent service.
+type restarter interface {
+    Restart() error
 }
+
+type systemdRestarter struct{ cmd string }
+
+func (s *systemdRestarter) Restart() error {
+    // Only restart if the service is active
+    if err := exec.Command(s.cmd, "is-active", "beszel-agent.service").Run(); err != nil {
+        return nil
+    }
+    log.Print("Restarting beszel-agent.service via systemd…")
+    return exec.Command(s.cmd, "restart", "beszel-agent.service").Run()
+}
+
+type openRCRestarter struct{ cmd string }
+
+func (o *openRCRestarter) Restart() error {
+    if err := exec.Command(o.cmd, "status", "beszel-agent").Run(); err != nil {
+        return nil
+    }
+    log.Print("Restarting beszel-agent via OpenRC…")
+    return exec.Command(o.cmd, "restart", "beszel-agent").Run()
+}
+
+type openWRTRestarter struct{ cmd string }
+
+func (w *openWRTRestarter) Restart() error {
+    if err := exec.Command(w.cmd, "running", "beszel-agent").Run(); err != nil {
+        return nil
+    }
+    log.Print("Restarting beszel-agent via procd…")
+    return exec.Command(w.cmd, "restart", "beszel-agent").Run()
+}
+
+func detectRestarter() restarter {
+    if path, err := exec.LookPath("systemctl"); err == nil {
+        return &systemdRestarter{cmd: path}
+    }
+    if path, err := exec.LookPath("rc-service"); err == nil {
+        return &openRCRestarter{cmd: path}
+    }
+    if path, err := exec.LookPath("service"); err == nil {
+        return &openWRTRestarter{cmd: path}
+    }
+    return nil
+}
+
+// Update checks GitHub for a newer release of beszel-agent, applies it,
+// fixes SELinux context if needed, and restarts the service.
+func Update() error {
+    // 1) Parse current version
+    current, err := semver.Parse(beszel.Version)
+    if err != nil {
+        return fmt.Errorf("invalid current version %q: %w", beszel.Version, err)
+    }
+    log.Printf("Current version: %s", current)
+
+    // 2) Create updater with our binary name filter
+    updater, err := selfupdate.NewUpdater(selfupdate.Config{
+        Filters: []string{"beszel-agent"},
+    })
+    if err != nil {
+        return fmt.Errorf("creating self-update client: %w", err)
+    }
+
+    // 3) Detect latest
+    log.Print("Checking for updates…")
+    latest, found, err := updater.DetectLatest("henrygd/beszel")
+    if err != nil {
+        return fmt.Errorf("failed to detect latest release: %w", err)
+    }
+    if !found {
+        log.Print("No updates available.")
+        return nil
+    }
+    log.Printf("Latest version: %s", latest.Version)
+
+    // 4) Compare versions
+    if !latest.Version.GT(current) {
+        log.Print("You are already up to date.")
+        return nil
+    }
+
+    // 5) Perform the update
+    exePath, err := os.Executable()
+    if err != nil {
+        return fmt.Errorf("unable to locate executable: %w", err)
+    }
+    log.Printf("Updating from %s to %s…", current, latest.Version)
+    if err := updater.UpdateTo(latest, exePath); err != nil {
+        return fmt.Errorf("update failed: %w", err)
+    }
+    log.Printf("Successfully updated to %s", latest.Version)
+    log.Print("Release notes:\n", strings.TrimSpace(latest.ReleaseNotes))
+
+    // 6) Fix SELinux context if necessary
+    if err := handleSELinuxContext(exePath); err != nil {
+        log.Printf("Warning: SELinux context handling: %v", err)
+    }
+
+    // 7) Restart service if running under a recognised init system
+    if r := detectRestarter(); r != nil {
+        if err := r.Restart(); err != nil {
+            log.Printf("Warning: failed to restart service: %v", err)
+            log.Print("Please restart the service manually.")
+        }
+    } else {
+        log.Print("No supported init system detected; please restart manually if needed.")
+    }
+
+    return nil
+}
+
+// handleSELinuxContext restores or applies the correct SELinux label to the binary.
+func handleSELinuxContext(path string) error {
+    out, err := exec.Command("getenforce").Output()
+    if err != nil {
+        // SELinux not enabled or getenforce not available
+        return nil
+    }
+    state := strings.TrimSpace(string(out))
+    if state == "Disabled" {
+        return nil
+    }
+
+    log.Print("SELinux is enabled; applying context…")
+    var errs []string
+
+    // Try persistent context via semanage+restorecon
+    if semanagePath, err := exec.LookPath("semanage"); err == nil {
+        if err := exec.Command(semanagePath, "fcontext", "-a", "-t", "bin_t", path).Run(); err != nil {
+            errs = append(errs, "semanage fcontext failed: "+err.Error())
+        } else if restoreconPath, err := exec.LookPath("restorecon"); err == nil {
+            if err := exec.Command(restoreconPath, "-v", path).Run(); err != nil {
+                errs = append(errs, "restorecon failed: "+err.Error())
+            }
+        }
+    }
+
+    // Fallback to temporary context via chcon
+    if chconPath, err := exec.LookPath("chcon"); err == nil {
+        if err := exec.Command(chconPath, "-t", "bin_t", path).Run(); err != nil {
+            errs = append(errs, "chcon failed: "+err.Error())
+        }
+    }
+
+    if len(errs) > 0 {
+        return fmt.Errorf("SELinux context errors: %s", strings.Join(errs, "; "))
+    }
+    return nil
+}