utils: T5239: add low-level read from config.boot (RPKI fixes)

python/vyos/util.py

@@ -968,3 +968,26 @@ def get_vrf_members(vrf: str) -> list:
         if 'ifname' in data:
             interfaces.append(data.get('ifname'))
     return interfaces
+
+def read_saved_value(path: list):
+    from vyos.defaults import directories
+    config_file = os.path.join(directories['config'], 'config.boot')
+
+    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)
+    if len(res) == 1:
+        return res[0]
+    res = ct.list_nodes(path)
+    if len(res) == 1:
+        return ' '.join(res)
+    return res

src/helpers/read-saved-value.py

@@ -0,0 +1,28 @@
+#!/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.util 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)