fix incorrect systemd booted check

Check for the directory /run/systemd/system, this is described in sd_booted(3). Reading /proc/1/comm will fail when /proc is mounted with the `hidepid=2` option. [NO NEW TESTS NEEDED] Fixes containers#16022 Signed-off-by: Paul Holzinger <[email protected]>
Luap99 · Nov 7, 2022 · 919678d · 919678d
1 parent 9e04bab
commit 919678d
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/utils/utils.go b/utils/utils.go
@@ -113,9 +113,9 @@ var (
 // RunsOnSystemd returns whether the system is using systemd
 func RunsOnSystemd() bool {
 	runsOnSystemdOnce.Do(func() {
-		initCommand, err := os.ReadFile("/proc/1/comm")
-		// On errors, default to systemd
-		runsOnSystemd = err != nil || strings.TrimRight(string(initCommand), "\n") == "systemd"
+		// per sd_booted(3), check for this dir
+		fd, err := os.Stat("/run/systemd/system")
+		runsOnSystemd = err == nil && fd.IsDir()
 	})
 	return runsOnSystemd
 }