From f54ebeac5b95c7481718e09c4598a86bc1a8dcfb Mon Sep 17 00:00:00 2001

From: Eduardo Otubo <otubo@redhat.com>

Date: Wed, 3 Jul 2019 13:14:53 +0200

Subject: [PATCH] Azure: Return static fallback address as if failed to find

 endpoint

RH-Author: Eduardo Otubo <otubo@redhat.com>

Message-id: <20190703131453.15811-1-otubo@redhat.com>

Patchwork-id: 89354

O-Subject: [RHEL-7.8 cloud-init PATCH] Azure: Return static fallback address as if failed to find endpoint

Bugzilla: 1726701

RH-Acked-by: Bandan Das <bsd@redhat.com>

RH-Acked-by: Mohammed Gamal <mgamal@redhat.com>

BZ: 1687565

BRANCH: rhel7/master-18.5

UPSTREAM: baa478546d8cac98a706010699d64f8c2f70b5bf

BREW: 22476988

commit aefb0f1c281740ef307116509057770062d61375

Author: Jason Zions (MSFT) <jasonzio@microsoft.com>

Date:   Fri May 10 18:38:55 2019 +0000

    Azure: Return static fallback address as if failed to find endpoint

    The Azure data source helper attempts to use information in the dhcp

    lease to find the Wireserver endpoint (IP address). Under some unusual

    circumstances, those attempts will fail. This change uses a static

    address, known to be always correct in the Azure public and sovereign

    clouds, when the helper fails to locate a valid dhcp lease. This

    address is not guaranteed to be correct in Azure Stack environments;

    it's still best to use the information from the lease whenever possible.

Signed-off-by: Eduardo Otubo <otubo@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 cloudinit/sources/helpers/azure.py                   | 14 +++++++++++---

 tests/unittests/test_datasource/test_azure_helper.py |  9 +++++++--

 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/cloudinit/sources/helpers/azure.py b/cloudinit/sources/helpers/azure.py

index d3af05e..82c4c8c 100755

--- a/cloudinit/sources/helpers/azure.py

+++ b/cloudinit/sources/helpers/azure.py

@@ -20,6 +20,9 @@ from cloudinit.reporting import events

 LOG = logging.getLogger(__name__)

+# This endpoint matches the format as found in dhcp lease files, since this

+# value is applied if the endpoint can't be found within a lease file

+DEFAULT_WIRESERVER_ENDPOINT = "a8:3f:81:10"

 azure_ds_reporter = events.ReportEventStack(

     name="azure-ds",

@@ -297,7 +300,12 @@ class WALinuxAgentShim(object):

     @azure_ds_telemetry_reporter

     def _get_value_from_leases_file(fallback_lease_file):

         leases = []

-        content = util.load_file(fallback_lease_file)

+        try:

+            content = util.load_file(fallback_lease_file)

+        except IOError as ex:

+            LOG.error("Failed to read %s: %s", fallback_lease_file, ex)

+            return None

+

         LOG.debug("content is %s", content)

         option_name = _get_dhcp_endpoint_option_name()

         for line in content.splitlines():

@@ -372,9 +380,9 @@ class WALinuxAgentShim(object):

                           fallback_lease_file)

                 value = WALinuxAgentShim._get_value_from_leases_file(

                     fallback_lease_file)

-

         if value is None:

-            raise ValueError('No endpoint found.')

+            LOG.warning("No lease found; using default endpoint")

+            value = DEFAULT_WIRESERVER_ENDPOINT

         endpoint_ip_address = WALinuxAgentShim.get_ip_from_lease_value(value)

         LOG.debug('Azure endpoint found at %s', endpoint_ip_address)

diff --git a/tests/unittests/test_datasource/test_azure_helper.py b/tests/unittests/test_datasource/test_azure_helper.py

index 0255616..bd006ab 100644

--- a/tests/unittests/test_datasource/test_azure_helper.py

+++ b/tests/unittests/test_datasource/test_azure_helper.py

@@ -67,12 +67,17 @@ class TestFindEndpoint(CiTestCase):

         self.networkd_leases.return_value = None

     def test_missing_file(self):

-        self.assertRaises(ValueError, wa_shim.find_endpoint)

+        """wa_shim find_endpoint uses default endpoint if leasefile not found

+        """

+        self.assertEqual(wa_shim.find_endpoint(), "168.63.129.16")

     def test_missing_special_azure_line(self):

+        """wa_shim find_endpoint uses default endpoint if leasefile is found

+        but does not contain DHCP Option 245 (whose value is the endpoint)

+        """

         self.load_file.return_value = ''

         self.dhcp_options.return_value = {'eth0': {'key': 'value'}}

-        self.assertRaises(ValueError, wa_shim.find_endpoint)

+        self.assertEqual(wa_shim.find_endpoint(), "168.63.129.16")

     @staticmethod

     def _build_lease_content(encoded_address):

-- 

1.8.3.1