cli/boot: fix possible KeyError in _waitIpv6Ready

slapos/cli/boot.py

@@ -141,15 +141,13 @@ def _waitIpv6Ready(ipv6_interface):
   """
     test if ipv6 is ready on ipv6_interface
   """
-  ipv6_address = ""
   print("[BOOT] Checking if %r has IPv6..." % ipv6_interface)
-  while ipv6_address == "":
-    for inet_dict in netifaces.ifaddresses(ipv6_interface)[socket.AF_INET6]:
+  while True:
+    for inet_dict in netifaces.ifaddresses(ipv6_interface).get(socket.AF_INET6, ()):
       ipv6_address = inet_dict['addr'].split('%')[0]
       if isGlobalScopeAddress(ipv6_address):
-        break
-    else:
-      ipv6_address = ""
+        return
+
     print("[BOOT] [ERROR] No IPv6 found on interface %r, "
           "try again in 5 seconds..." % ipv6_interface)
     sleep(5)

slapos/tests/test_cli.py

@@ -340,14 +340,19 @@ class TestCliBoot(CliMixin):
               timestamp)
 
   def test_boot_failure(self):
-    # In this test, node and bang command will fail two time each.
+    # In this test, the network interfaces will not have
+    # IP address at the beginning, the global IPv6 address only appears later,
+    # then format and bang commands will fail two time each.
     # `slapos node boot` command retries on failures.
 
     app = slapos.cli.entry.SlapOSApp()
+    net1 = {socket.AF_INET: ({'addr': '127.0.0.1'},),}
+    net2 = {socket.AF_INET: ({'addr': '127.0.0.1'},), socket.AF_INET6: ({'addr': 'fe80::1'},),}
+    net3 = {socket.AF_INET: ({'addr': '127.0.0.1'},), socket.AF_INET6: ({'addr': 'fe80::1'}, {'addr': '2000::1'},),}
     with patch('slapos.cli.boot.check_root_user', return_value=True) as check_root_user,\
         patch('slapos.cli.boot.sleep') as sleep,\
         patch('slapos.cli.boot.netifaces.ifaddresses',
-              return_value={socket.AF_INET6: ({'addr': '2000::1'},),},),\
+              side_effect=[net1, net2, net3]),\
         patch('slapos.cli.boot._ping_hostname', return_value=0),\
         patch('slapos.cli.format.check_root_user', return_value=True),\
         patch('slapos.cli.format.logging.FileHandler', return_value=logging.NullHandler()),\
@@ -362,8 +367,9 @@ class TestCliBoot(CliMixin):
     self.assertEqual(do_format.call_count, 3)
     self.assertEqual(do_bang.call_count, 3)
 
-    # between retries we sleep 15 seconds.
-    sleep.assert_called_with(15)
+    # between retries of ping, we sleep 5 seconds
+    # between retries of bang, we sleep 15 seconds
+    self.assertEqual(sleep.mock_calls, [mock.call(5)]*2 + [mock.call(15)]*4)
 
     # we have only one logger on the console
     from slapos.cli import coloredlogs