cloud-init-dev team mailing list archive

[Dan Watkins <daniel.watkins@xxxxxxxxxxxxx>]

Dan Watkins has proposed merging lp:~daniel-thewatkins/cloud-init/shim_fixes into lp:cloud-init.

Requested reviews:
  cloud init development team (cloud-init-dev)
Related bugs:
  Bug #1488891 in cloud-init: "WALinuxAgentShim fails to handle escaped characters in dhclient.eth0.leases"
  https://bugs.launchpad.net/cloud-init/+bug/1488891
  Bug #1488896 in cloud-init: "WALinuxAgentShim fails to handle colons in packed values in dhclient.eth0.leases"
  https://bugs.launchpad.net/cloud-init/+bug/1488896

For more details, see:
https://code.launchpad.net/~daniel-thewatkins/cloud-init/shim_fixes/+merge/273977
-- 
Your team cloud init development team is requested to review the proposed merge of lp:~daniel-thewatkins/cloud-init/shim_fixes into lp:cloud-init.

=== modified file 'cloudinit/sources/helpers/azure.py'
--- cloudinit/sources/helpers/azure.py	2015-05-08 15:52:58 +0000
+++ cloudinit/sources/helpers/azure.py	2015-10-09 13:02:16 +0000
@@ -216,6 +216,21 @@
             self.openssl_manager.clean_up()
 
     @staticmethod
+    def get_ip_from_lease_value(lease_value):
+        unescaped_value = lease_value.replace('\\', '')
+        if len(unescaped_value) > 4:
+            hex_string = ''
+            for hex_pair in unescaped_value.split(':'):
+                if len(hex_pair) == 1:
+                    hex_pair = '0' + hex_pair
+                hex_string += hex_pair
+            packed_bytes = struct.pack(
+                '>L', int(hex_string.replace(':', ''), 16))
+        else:
+            packed_bytes = unescaped_value.encode('utf-8')
+        return socket.inet_ntoa(packed_bytes)
+
+    @staticmethod
     def find_endpoint():
         LOG.debug('Finding Azure endpoint...')
         content = util.load_file('/var/lib/dhcp/dhclient.eth0.leases')
@@ -225,16 +240,7 @@
                 value = line.strip(' ').split(' ', 2)[-1].strip(';\n"')
         if value is None:
             raise Exception('No endpoint found in DHCP config.')
-        if ':' in value:
-            hex_string = ''
-            for hex_pair in value.split(':'):
-                if len(hex_pair) == 1:
-                    hex_pair = '0' + hex_pair
-                hex_string += hex_pair
-            value = struct.pack('>L', int(hex_string.replace(':', ''), 16))
-        else:
-            value = value.encode('utf-8')
-        endpoint_ip_address = socket.inet_ntoa(value)
+        endpoint_ip_address = WALinuxAgentShim.get_ip_from_lease_value(value)
         LOG.debug('Azure endpoint found at %s', endpoint_ip_address)
         return endpoint_ip_address
 

=== modified file 'tests/unittests/test_datasource/test_azure_helper.py'
--- tests/unittests/test_datasource/test_azure_helper.py	2015-05-15 20:28:24 +0000
+++ tests/unittests/test_datasource/test_azure_helper.py	2015-10-09 13:02:16 +0000
@@ -90,48 +90,64 @@
         self.assertRaises(Exception,
                           azure_helper.WALinuxAgentShim.find_endpoint)
 
-    def _build_lease_content(self, ip_address, use_hex=True):
-        ip_address_repr = ':'.join(
-            [hex(int(part)).replace('0x', '')
-             for part in ip_address.split('.')])
-        if not use_hex:
-            ip_address_repr = struct.pack(
-                '>L', int(ip_address_repr.replace(':', ''), 16))
-            ip_address_repr = '"{0}"'.format(ip_address_repr.decode('utf-8'))
+    @staticmethod
+    def _build_lease_content(encoded_address):
         return '\n'.join([
             'lease {',
             ' interface "eth0";',
-            ' option unknown-245 {0};'.format(ip_address_repr),
+            ' option unknown-245 {0};'.format(encoded_address),
             '}'])
 
+    def test_latest_lease_used(self):
+        encoded_addresses = ['5:4:3:2', '4:3:2:1']
+        file_content = '\n'.join([self._build_lease_content(encoded_address)
+                                  for encoded_address in encoded_addresses])
+        self.load_file.return_value = file_content
+        self.assertEqual(encoded_addresses[-1].replace(':', '.'),
+                         azure_helper.WALinuxAgentShim.find_endpoint())
+
+
+class TestExtractIpAddressFromLeaseValue(TestCase):
+
     def test_hex_string(self):
-        ip_address = '98.76.54.32'
-        file_content = self._build_lease_content(ip_address)
-        self.load_file.return_value = file_content
-        self.assertEqual(ip_address,
-                         azure_helper.WALinuxAgentShim.find_endpoint())
+        ip_address, encoded_address = '98.76.54.32', '62:4c:36:20'
+        self.assertEqual(
+            ip_address,
+            azure_helper.WALinuxAgentShim.get_ip_from_lease_value(
+                encoded_address
+            ))
 
     def test_hex_string_with_single_character_part(self):
-        ip_address = '4.3.2.1'
-        file_content = self._build_lease_content(ip_address)
-        self.load_file.return_value = file_content
-        self.assertEqual(ip_address,
-                         azure_helper.WALinuxAgentShim.find_endpoint())
+        ip_address, encoded_address = '4.3.2.1', '4:3:2:1'
+        self.assertEqual(
+            ip_address,
+            azure_helper.WALinuxAgentShim.get_ip_from_lease_value(
+                encoded_address
+            ))
 
     def test_packed_string(self):
-        ip_address = '98.76.54.32'
-        file_content = self._build_lease_content(ip_address, use_hex=False)
-        self.load_file.return_value = file_content
-        self.assertEqual(ip_address,
-                         azure_helper.WALinuxAgentShim.find_endpoint())
-
-    def test_latest_lease_used(self):
-        ip_addresses = ['4.3.2.1', '98.76.54.32']
-        file_content = '\n'.join([self._build_lease_content(ip_address)
-                                  for ip_address in ip_addresses])
-        self.load_file.return_value = file_content
-        self.assertEqual(ip_addresses[-1],
-                         azure_helper.WALinuxAgentShim.find_endpoint())
+        ip_address, encoded_address = '98.76.54.32', 'bL6 '
+        self.assertEqual(
+            ip_address,
+            azure_helper.WALinuxAgentShim.get_ip_from_lease_value(
+                encoded_address
+            ))
+
+    def test_packed_string_with_escaped_quote(self):
+        ip_address, encoded_address = '100.72.34.108', 'dH\\"l'
+        self.assertEqual(
+            ip_address,
+            azure_helper.WALinuxAgentShim.get_ip_from_lease_value(
+                encoded_address
+            ))
+
+    def test_packed_string_containing_a_colon(self):
+        ip_address, encoded_address = '100.72.58.108', 'dH:l'
+        self.assertEqual(
+            ip_address,
+            azure_helper.WALinuxAgentShim.get_ip_from_lease_value(
+                encoded_address
+            ))
 
 
 class TestGoalStateParsing(TestCase):