Azure: adding support for consuming userdata from IMDS (#884)

2 files changed, 72 insertions, 1 deletions

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index 38790c12..c0025c7b 100755
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -83,7 +83,7 @@ AGENT_SEED_DIR = '/var/lib/waagent'
 IMDS_TIMEOUT_IN_SECONDS = 2
 IMDS_URL = "http://169.254.169.254/metadata"
 IMDS_VER_MIN = "2019-06-01"
-IMDS_VER_WANT = "2020-10-01"
+IMDS_VER_WANT = "2021-01-01"
 
 
 # This holds SSH key data including if the source was
@@ -539,6 +539,20 @@ class DataSourceAzure(sources.DataSource):
                     imds_disable_password
                 )
                 crawled_data['metadata']['disable_password'] = imds_disable_password  # noqa: E501
+
+            # only use userdata from imds if OVF did not provide custom data
+            # userdata provided by IMDS is always base64 encoded
+            if not userdata_raw:
+                imds_userdata = _userdata_from_imds(imds_md)
+                if imds_userdata:
+                    LOG.debug("Retrieved userdata from IMDS")
+                    try:
+                        crawled_data['userdata_raw'] = base64.b64decode(
+                            ''.join(imds_userdata.split()))
+                    except Exception:
+                        report_diagnostic_event(
+                            "Bad userdata in IMDS",
+                            logger_func=LOG.warning)
             found = cdev
 
             report_diagnostic_event(
@@ -1512,6 +1526,13 @@ def _username_from_imds(imds_data):
         return None
 
 
+def _userdata_from_imds(imds_data):
+    try:
+        return imds_data['compute']['userData']
+    except KeyError:
+        return None
+
+
 def _hostname_from_imds(imds_data):
     try:
         return imds_data['compute']['osProfile']['computerName']
diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py
index c4a8e08d..f8433690 100644
--- a/tests/unittests/test_datasource/test_azure.py
+++ b/tests/unittests/test_datasource/test_azure.py
@@ -1899,6 +1899,56 @@ scbus-1 on xpt0 bus 0
         dsrc.get_data()
         self.assertTrue(dsrc.metadata["disable_password"])
 
+    @mock.patch(MOCKPATH + 'get_metadata_from_imds')
+    def test_userdata_from_imds(self, m_get_metadata_from_imds):
+        sys_cfg = {'datasource': {'Azure': {'apply_network_config': True}}}
+        odata = {'HostName': "myhost", 'UserName': "myuser"}
+        data = {
+            'ovfcontent': construct_valid_ovf_env(data=odata),
+            'sys_cfg': sys_cfg
+        }
+        userdata = "userdataImds"
+        imds_data = copy.deepcopy(NETWORK_METADATA)
+        imds_data["compute"]["osProfile"] = dict(
+            adminUsername="username1",
+            computerName="hostname1",
+            disablePasswordAuthentication="true",
+        )
+        imds_data["compute"]["userData"] = b64e(userdata)
+        m_get_metadata_from_imds.return_value = imds_data
+        dsrc = self._get_ds(data)
+        ret = dsrc.get_data()
+        self.assertTrue(ret)
+        self.assertEqual(dsrc.userdata_raw, userdata.encode('utf-8'))
+
+    @mock.patch(MOCKPATH + 'get_metadata_from_imds')
+    def test_userdata_from_imds_with_customdata_from_OVF(
+            self, m_get_metadata_from_imds):
+        userdataOVF = "userdataOVF"
+        odata = {
+            'HostName': "myhost", 'UserName': "myuser",
+            'UserData': {'text': b64e(userdataOVF), 'encoding': 'base64'}
+        }
+        sys_cfg = {'datasource': {'Azure': {'apply_network_config': True}}}
+        data = {
+            'ovfcontent': construct_valid_ovf_env(data=odata),
+            'sys_cfg': sys_cfg
+        }
+
+        userdataImds = "userdataImds"
+        imds_data = copy.deepcopy(NETWORK_METADATA)
+        imds_data["compute"]["osProfile"] = dict(
+            adminUsername="username1",
+            computerName="hostname1",
+            disablePasswordAuthentication="true",
+        )
+        imds_data["compute"]["userData"] = b64e(userdataImds)
+        m_get_metadata_from_imds.return_value = imds_data
+        dsrc = self._get_ds(data)
+        ret = dsrc.get_data()
+        self.assertTrue(ret)
+        self.assertEqual(dsrc.userdata_raw, userdataOVF.encode('utf-8'))
+
 
 class TestAzureBounce(CiTestCase):