Fix virtual router nftables restore at boot

systemvm/debian/opt/cloud/bin/configure.py

@@ -1609,7 +1609,7 @@ def process(self):
         CsHelper.save_iptables("ip6tables-save", "/etc/iptables/rules.v6")
 
         # Save nftables configuration
-        CsHelper.save_iptables("nft list ruleset", "/etc/iptables/rules.nftables")
+        CsHelper.save_nftables("/etc/iptables/rules.nftables")
 
 def main(argv):
     # The file we are currently processing, if it is "cmd_line.json" everything will be processed.

systemvm/debian/opt/cloud/bin/cs/CsHelper.py

@@ -210,13 +210,37 @@ def save_iptables(command, iptables_file):
     """ Execute command """
     logging.debug("Saving iptables for %s" % command)
 
-    result = execute(command)
-    fIptables = open(iptables_file, "w+")
+    write_lines(iptables_file, execute(command))
 
-    for line in result:
-        fIptables.write(line)
-        fIptables.write("\n")
-    fIptables.close()
+
+def write_lines(path, lines):
+    with open(path, "w+") as f:
+        for line in lines:
+            f.write(line)
+            f.write("\n")
+
+
+IPTABLES_FAMILIES = ["ip", "ip6", "arp", "bridge"]
+IPTABLES_TABLES = ["filter", "nat", "mangle", "raw", "security", "broute"]
+
+
+def save_nftables(nftables_file):
+    """ Save the tables that only nftables manages, such as the IPv6 firewall and ACLs. The iptables-nft tables are
+    saved by save_iptables and restored with iptables-restore. nft can't load them, and one of them in the file fails
+    the whole restore at boot. """
+    logging.debug("Saving nftables tables to %s" % nftables_file)
+
+    rules = []
+    for line in execute("nft list tables"):
+        table = line.split()
+        if len(table) != 3 or table[0] != "table":
+            continue
+        family, name = table[1], table[2]
+        if family in IPTABLES_FAMILIES and name in IPTABLES_TABLES:
+            continue
+        rules.extend(execute("nft list table %s %s" % (family, name)))
+
+    write_lines(nftables_file, rules)
 
 
 def execute2(command, wait=True):

systemvm/test/TestCsHelper.py

@@ -15,6 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
+import tempfile
 import unittest
 import mock
 from cs import CsHelper
@@ -31,6 +32,36 @@ def test_execute(self, mock_subprocess):
         result = CsHelper.execute("/bin/false")
         self.assertTrue(result is not None)
 
+    @mock.patch('cs.CsHelper.execute')
+    def test_save_iptables_writes_the_command_output(self, mock_execute):
+        mock_execute.return_value = ["*filter", "COMMIT"]
+
+        with tempfile.NamedTemporaryFile(mode="r") as saved:
+            CsHelper.save_iptables("iptables-save", saved.name)
+            self.assertEqual("*filter\nCOMMIT\n", saved.read())
+        mock_execute.assert_called_once_with("iptables-save")
+
+    @mock.patch('cs.CsHelper.execute')
+    def test_save_nftables_leaves_out_iptables_tables(self, mock_execute):
+        tables = ["table ip filter", "table ip nat", "table ip mangle", "table ip6 filter", "table ip6 raw",
+                  "table bridge broute", "table ip6 ip6_firewall", "table ip ip4_firewall", "table inet cloudstack"]
+        mock_execute.side_effect = lambda command: tables if command == "nft list tables" else \
+            ["%s {" % command.replace("nft list ", ""), "}"]
+
+        with tempfile.NamedTemporaryFile(mode="r") as saved:
+            CsHelper.save_nftables(saved.name)
+            content = saved.read()
+
+        self.assertEqual("table ip6 ip6_firewall {\n}\ntable ip ip4_firewall {\n}\ntable inet cloudstack {\n}\n", content)
+
+    @mock.patch('cs.CsHelper.execute')
+    def test_save_nftables_writes_an_empty_file_without_nftables_tables(self, mock_execute):
+        mock_execute.side_effect = lambda command: ["table ip filter", "table ip nat"] if command == "nft list tables" else ["x"]
+
+        with tempfile.NamedTemporaryFile(mode="r") as saved:
+            CsHelper.save_nftables(saved.name)
+            self.assertEqual("", saved.read())
+
 
 if __name__ == '__main__':
     unittest.main()