T1967: add a migration script for the enforce-first-as option.

1 files changed, 19 insertions, 6 deletions

diff --git a/src/migration-scripts/quagga/3-to-4 b/src/migration-scripts/quagga/3-to-4
index f8c87ce8c..be3528391 100755
--- a/src/migration-scripts/quagga/3-to-4
+++ b/src/migration-scripts/quagga/3-to-4
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2019 VyOS maintainers and contributors
+# Copyright (C) 2020 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
@@ -16,6 +16,13 @@
 #
 #
 
+# Between 1.2.3 and 1.2.4, FRR added per-neighbor enforce-first-as option.
+# Unfortunately they also removed the global enforce-first-as option,
+# which broke all old configs that used to have it.
+#
+# To emulate the effect of the original option, we insert it in every neighbor
+# if the config used to have the original global option
+
 import sys
 
 from vyos.configtree import ConfigTree
@@ -45,11 +52,16 @@ else:
         # There's actually no BGP, just its empty shell
         sys.exit(0)
 
-    # Check if BGP scan-time parameter exist
-    scan_time_param = ['protocols', 'bgp', asn, 'parameters', 'scan-time']
-    if config.exists(scan_time_param):
-        # Delete BGP scan-time parameter
-        config.delete(scan_time_param)
+    # Check if BGP enforce-first-as option is set
+    enforce_first_as_path = ['protocols', 'bgp', asn, 'parameters', 'enforce-first-as']
+    if config.exists(enforce_first_as_path):
+        # Delete the obsolete option
+        config.delete(enforce_first_as_path)
+
+        # Now insert it in every peer
+        peers = config.list_nodes(['protocols', 'bgp', asn, 'neighbor'])
+        for p in peers:
+            config.set(['protocols', 'bgp', asn, 'neighbor', p, 'enforce-first-as'])
     else:
         # Do nothing
         sys.exit(0)
@@ -61,3 +73,4 @@ else:
     except OSError as e:
         print("Failed to save the modified config: {}".format(e))
         sys.exit(1)
+