main: explain our /etc empty check a bit in a comment

[elogind.git] / src / core / main.c

diff --git a/src/core/main.c b/src/core/main.c
index 8ee12ef8fabfe49050702728da3e6b32da0eb8f7..a732c6945afc5a671d134e235cafd31e03241771 100644 (file)
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1543,13 +1543,22 @@ int main(int argc, char *argv[]) {
                 if (in_initrd())
                         log_info("Running in initial RAM disk.");
 
-                empty_etc = dir_is_empty("/etc") > 0;
+                /* Let's check whether /etc is already populated. We
+                 * don't actually really check for that, but use
+                 * /etc/machine-id as flag file. This allows container
+                 * managers and installers to provision a couple of
+                 * files already. If the container manager wants to
+                 * provision the machine ID itself it should pass
+                 * $container_uuid to PID 1.*/
+
+                empty_etc = access("/etc/machine-id", F_OK) < 0;
                 if (empty_etc)
                         log_info("Running with unpopulated /etc.");
         } else {
-                _cleanup_free_ char *t = uid_to_name(getuid());
-                log_debug(PACKAGE_STRING " running in user mode for user "UID_FMT"/%s. (" SYSTEMD_FEATURES ")",
-                          getuid(), t);
+                _cleanup_free_ char *t;
+
+                t = uid_to_name(getuid());
+                log_debug(PACKAGE_STRING " running in user mode for user "UID_FMT"/%s. (" SYSTEMD_FEATURES ")", getuid(), strna(t));
         }
 
         if (arg_running_as == SYSTEMD_SYSTEM && !skip_setup) {