Merge pull request #2292 from vyos/mergify/bp/sagitta/pr-2289

init: T5239: configure system hostname prior to FRR startup (backport #2289)

3 files changed, 69 insertions, 2 deletions

diff --git a/python/vyos/utils/config.py b/python/vyos/utils/config.py
new file mode 100644
index 000000000..bd363ce46
--- /dev/null
+++ b/python/vyos/utils/config.py
@@ -0,0 +1,34 @@
+# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+from vyos.defaults import directories
+
+config_file = os.path.join(directories['config'], 'config.boot')
+
+def read_saved_value(path: list):
+    if not isinstance(path, list) or not path:
+        return ''
+    from vyos.configtree import ConfigTree
+    try:
+        with open(config_file) as f:
+            config_string = f.read()
+        ct = ConfigTree(config_string)
+    except Exception:
+        return ''
+    if not ct.exists(path):
+        return ''
+    res = ct.return_values(path)
+    return res[0] if len(res) == 1 else res
diff --git a/src/helpers/read-saved-value.py b/src/helpers/read-saved-value.py
new file mode 100755
index 000000000..1463e9ffe
--- /dev/null
+++ b/src/helpers/read-saved-value.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+from argparse import ArgumentParser
+from vyos.utils.config import read_saved_value
+
+if __name__ == '__main__':
+    parser = ArgumentParser()
+    parser.add_argument('--path', nargs='*')
+    args = parser.parse_args()
+
+    out = read_saved_value(args.path) if args.path else ''
+    if isinstance(out, list):
+        out = ' '.join(out)
+    print(out)
diff --git a/src/init/vyos-router b/src/init/vyos-router
index cc69fae5a..b8833a8a0 100755
--- a/src/init/vyos-router
+++ b/src/init/vyos-router
@@ -371,8 +371,11 @@ start ()
       && chgrp ${GROUP} ${vyatta_configdir}
     log_action_end_msg $?
 
-    rm -f /etc/hostname
-    ${vyos_conf_scripts_dir}/host_name.py || log_failure_msg "could not reset host-name"
+    # T5239: early read of system hostname as this value is read-only once during
+    # FRR initialisation
+    tmp=$(${vyos_libexec_dir}/read-saved-value.py --path "system host-name")
+    hostnamectl set-hostname --static "$tmp"
+
     ${vyos_conf_scripts_dir}/system_frr.py || log_failure_msg "could not reset FRR config"
     # If for any reason FRR was not started by system_frr.py - start it anyways.
     # This is a safety net!