on azure datasource, grab use Deployment as the instance-id

LP: #1204190

2 files changed, 65 insertions, 2 deletions

diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index c90d7b07..0a5caebe 100644
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -114,7 +114,8 @@ class DataSourceAzureNet(sources.DataSource):
             # claim the datasource even if the command failed
             util.logexc(LOG, "agent command '%s' failed.", mycfg['cmd'])
 
-        wait_for = [os.path.join(mycfg['datadir'], "SharedConfig.xml")]
+        shcfgxml = os.path.join(mycfg['datadir'], "SharedConfig.xml")
+        wait_for = [shcfgxml]
 
         fp_files = []
         for pk in self.cfg.get('_pubkeys', []):
@@ -129,6 +130,14 @@ class DataSourceAzureNet(sources.DataSource):
             LOG.debug("waited %.3f seconds for %d files to appear",
                       time.time() - start, len(wait_for))
 
+        if shcfgxml in missing:
+            LOG.warn("SharedConfig.xml missing, using static instance-id")
+        else:
+            try:
+                self.metadata['instance-id'] = iid_from_shared_config(shcfgxml)
+            except ValueError as e:
+                LOG.warn("failed to get instance id in %s: %s" % (shcfgxml, e))
+
         pubkeys = pubkeys_from_crt_files(fp_files)
 
         self.metadata['public-keys'] = pubkeys
@@ -252,6 +261,20 @@ def load_azure_ovf_pubkeys(sshnode):
     return found
 
 
+def single_node_at_path(node, pathlist):
+    curnode = node
+    for tok in pathlist:
+        results = find_child(curnode, lambda n: n.localName == tok)
+        if len(results) == 0:
+            raise ValueError("missing %s token in %s" % (tok, str(pathlist)))
+        if len(results) > 1:
+            raise ValueError("found %s nodes of type %s looking for %s" %
+                             (len(results), tok, str(pathlist)))
+        curnode = results[0]
+
+    return curnode
+
+
 def read_azure_ovf(contents):
     try:
         dom = minidom.parseString(contents)
@@ -362,6 +385,25 @@ def load_azure_ds_dir(source_dir):
     return (md, ud, cfg, {'ovf-env.xml': contents})
 
 
+def iid_from_shared_config(path):
+    with open(path, "rb") as fp:
+        content = fp.read()
+    return iid_from_shared_config_content(content)
+
+
+def iid_from_shared_config_content(content):
+    """
+    find INSTANCE_ID in:
+    <?xml version="1.0" encoding="utf-8"?>
+    <SharedConfig version="1.0.0.0" goalStateIncarnation="1">
+      <Deployment name="INSTANCE_ID" guid="{...}" incarnation="0">
+        <Service name="..." guid="{00000000-0000-0000-0000-000000000000}" />
+    """
+    dom = minidom.parseString(content)
+    depnode = single_node_at_path(dom, ["SharedConfig", "Deployment"])
+    return depnode.attributes.get('name').value
+
+
 class BrokenAzureDataSource(Exception):
     pass
 
diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py
index c79c25d8..2e8583f9 100644
--- a/tests/unittests/test_datasource/test_azure.py
+++ b/tests/unittests/test_datasource/test_azure.py
@@ -99,6 +99,10 @@ class TestAzureDataSource(MockerTestCase):
             data['pubkey_files'] = flist
             return ["pubkey_from: %s" % f for f in flist]
 
+        def _iid_from_shared_config(path):
+            data['iid_from_shared_cfg'] = path
+            return 'i-my-azure-id'
+
         if data.get('ovfcontent') is not None:
             populate_dir(os.path.join(self.paths.seed_dir, "azure"),
                          {'ovf-env.xml': data['ovfcontent']})
@@ -112,7 +116,9 @@ class TestAzureDataSource(MockerTestCase):
                             (mod, 'write_files', _write_files),
                             (mod, 'wait_for_files', _wait_for_files),
                             (mod, 'pubkeys_from_crt_files',
-                             _pubkeys_from_crt_files)])
+                             _pubkeys_from_crt_files),
+                            (mod, 'iid_from_shared_config',
+                             _iid_from_shared_config), ])
 
         dsrc = mod.DataSourceAzureNet(
             data.get('sys_cfg', {}), distro=None, paths=self.paths)
@@ -131,6 +137,7 @@ class TestAzureDataSource(MockerTestCase):
         self.assertEqual(dsrc.metadata['local-hostname'], odata['HostName'])
         self.assertTrue('ovf-env.xml' in data['files'])
         self.assertEqual(0700, data['datadir_mode'])
+        self.assertEqual(dsrc.metadata['instance-id'], 'i-my-azure-id')
 
     def test_user_cfg_set_agent_command(self):
         cfg = {'agent_command': "my_command"}
@@ -227,6 +234,20 @@ class TestReadAzureOvf(MockerTestCase):
             self.assertIn(mypk, cfg['_pubkeys'])
 
 
+class TestReadAzureSharedConfig(MockerTestCase):
+    def test_valid_content(self):
+        xml = """<?xml version="1.0" encoding="utf-8"?>
+            <SharedConfig>
+             <Deployment name="MY_INSTANCE_ID">
+              <Service name="myservice"/>
+              <ServiceInstance name="INSTANCE_ID.0" guid="{abcd-uuid}" />
+             </Deployment>
+            <Incarnation number="1"/>
+            </SharedConfig>"""
+        ret = DataSourceAzure.iid_from_shared_config_content(xml)
+        self.assertEqual("MY_INSTANCE_ID", ret)
+
+
 def apply_patches(patches):
     ret = []
     for (ref, name, replace) in patches: