bgp: T3391: migrate old IPv4 only maximum-paths config to new syntax

1 files changed, 61 insertions, 0 deletions

diff --git a/src/migration-scripts/quagga/8-to-9 b/src/migration-scripts/quagga/8-to-9
new file mode 100755
index 000000000..15c44924f
--- /dev/null
+++ b/src/migration-scripts/quagga/8-to-9
@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 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/>.
+
+# - T3391: Migrate "maximum-paths" setting from "protocols bgp asn maximum-paths"
+#   under the IPv4 address-family tree. Reason is we currently have no way in
+#   configuring this for IPv6 address-family. This mimics the FRR configuration.
+
+from sys import argv
+from sys import exit
+from vyos.configtree import ConfigTree
+
+if (len(argv) < 2):
+    print("Must specify file name!")
+    exit(1)
+
+file_name = argv[1]
+
+with open(file_name, 'r') as f:
+    config_file = f.read()
+
+base = ['protocols', 'bgp']
+config = ConfigTree(config_file)
+
+if not config.exists(base):
+    # Nothing to do
+    exit(0)
+
+# Check if BGP is actually configured and obtain the ASN
+asn_list = config.list_nodes(base)
+if asn_list:
+    # There's always just one BGP node, if any
+    bgp_base = base + [asn_list[0]]
+
+    maximum_paths = bgp_base + ['maximum-paths']
+    if config.exists(maximum_paths):
+        for bgp_type in ['ebgp', 'ibgp']:
+            if config.exists(maximum_paths + [bgp_type]):
+                new_base =  bgp_base + ['address-family', 'ipv4-unicast', 'maximum-paths']
+                config.set(new_base)
+                config.copy(maximum_paths + [bgp_type], new_base + [bgp_type])
+        config.delete(maximum_paths)
+
+try:
+    with open(file_name, 'w') as f:
+        f.write(config.to_string())
+except OSError as e:
+    print("Failed to save the modified config: {}".format(e))
+    exit(1)