tunnel: T3364: rename encapsulation mode "gre-bridge" to "gretap"

The following list shows the mapping of VyOS tunnel encapsulation modes to the
corresponding Linux modes.

VyOS        Linux
gre         gre
gre-bridge  gretap
ipip        ipip
ipip6       ipip6
ip6ip6      ip6ip6
ip6gre      ip6gre
sit         sit

Besides gre-bridge this is pretty consistent. As bridge interfaces are also
called tap interfaces gre-bridge will be renamed to gretap to make the
post-processing much easier.

This means (in detail) that there are no more child classes of _Tunnel and
there will be now one geneirc TunnelIf class handling all sorts of encapsulation.

1 files changed, 51 insertions, 0 deletions

diff --git a/src/migration-scripts/interfaces/19-to-20 b/src/migration-scripts/interfaces/19-to-20
new file mode 100755
index 000000000..be42cdd61
--- /dev/null
+++ b/src/migration-scripts/interfaces/19-to-20
@@ -0,0 +1,51 @@
+#!/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/>.
+
+from sys import argv
+from sys import exit
+from vyos.configtree import ConfigTree
+
+if __name__ == '__main__':
+    if (len(argv) < 1):
+        print("Must specify file name!")
+        exit(1)
+
+    file_name = argv[1]
+    with open(file_name, 'r') as f:
+        config_file = f.read()
+
+    config = ConfigTree(config_file)
+    base = ['interfaces', 'tunnel']
+
+    if not config.exists(base):
+        # Nothing to do
+        exit(0)
+
+    #
+    # Migrate "interface tunnel <tunX> encapsulation gre-bridge" to gretap
+    for interface in config.list_nodes(base):
+        path = base + [interface, 'encapsulation']
+        if config.exists(path):
+            tmp = config.return_value(path)
+            if tmp == 'gre-bridge':
+                config.set(path, value='gretap')
+
+    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)