0014-Set-a-default-unique-hostname-when-it-is-either-clr-.patch

From 8280f2efacd6ad9d43a5aa9adcc3e513be972944 Mon Sep 17 00:00:00 2001
From: Ikey Doherty <michael.i.doherty@intel.com>
Date: Thu, 14 Apr 2016 19:15:46 +0100
Subject: [PATCH 14/38] Set a default, unique, hostname, when it is either
 'clr' or 'localhost'

Signed-off-by: Ikey Doherty <michael.i.doherty@intel.com>
---
 src/core/main.c             |  1 +
 src/shared/hostname-setup.c | 37 +++++++++++++++++++++++++++++++++++++
 src/shared/hostname-setup.h |  1 +
 3 files changed, 39 insertions(+)

diff --git a/src/shared/hostname-setup.c b/src/shared/hostname-setup.c
index 0fac0ecab7..d9b5529c2f 100644
--- a/src/shared/hostname-setup.c
+++ b/src/shared/hostname-setup.c
@@ -220,3 +220,40 @@ static const char* const hostname_source_table[] = {
 };
 
 DEFINE_STRING_TABLE_LOOKUP(hostname_source, HostnameSource);
+
+int set_first_hostname(void)
+{
+        char h[HOST_NAME_MAX+1];
+        h[HOST_NAME_MAX] = '\0';
+        _cleanup_free_ char *n_host = NULL;
+        _cleanup_free_ char *mid = NULL;
+
+        if (access("/etc/hostname", F_OK) == 0) {
+                return 1;
+        }
+
+        if (gethostname(h, HOST_NAME_MAX) != 0) {
+                return 0;
+        }
+
+        if (!streq(h, "clr") && !streq(h, "localhost")) {
+                return 0;
+        }
+
+        if (read_etc_hostname("/etc/machine-id", &mid) != 0) {
+                /* First boot, use transient machine-id until synced */
+                if (read_etc_hostname("/run/machine-id", &mid) != 0) {
+                        return 0;
+                }
+        }
+
+        if (!asprintf(&n_host, "clr-%s", mid)) {
+                return 0;
+        }
+
+        if (sethostname_idempotent(n_host) != 0) {
+                return 1;
+        }
+
+        return 0;
+}
diff --git a/src/shared/hostname-setup.h b/src/shared/hostname-setup.h
index 6def36c350..c9d880166e 100644
--- a/src/shared/hostname-setup.h
+++ b/src/shared/hostname-setup.h
@@ -23,3 +23,4 @@ int read_etc_hostname(const char *path, char **ret);
 
 void hostname_update_source_hint(const char *hostname, HostnameSource source);
 int hostname_setup(bool really);
+int set_first_hostname(void);
-- 
2.36.1

--- systemd-stable-255.2/src/core/main.c~	2023-12-24 09:00:51.000000000 +0000
+++ systemd-stable-255.2/src/core/main.c	2024-01-02 15:32:38.681980582 +0000
@@ -2236,6 +2236,7 @@
                         (void) hostname_setup(true);
                         /* Force transient machine-id on first boot. */
                         machine_id_setup(/* root= */ NULL, /* force_transient= */ first_boot, arg_machine_id, /* ret_machine_id */ NULL);
+			set_first_hostname();
                         (void) loopback_setup();
                         bump_unix_max_dgram_qlen();
                         bump_file_max_and_nr_open();