merge with trunk

3 files changed, 17 insertions, 2 deletions

diff --git a/cloudinit/distros/debian.py b/cloudinit/distros/debian.py
index 53f3aa4d..5ae9a509 100644
--- a/cloudinit/distros/debian.py
+++ b/cloudinit/distros/debian.py
@@ -43,6 +43,13 @@ APT_GET_WRAPPER = {
     'enabled': 'auto',
 }
 
+ENI_HEADER = """# This file is generated from information provided by
+# the datasource.  Changes to it will not persist across an instance.
+# To disable cloud-init's network configuration capabilities, write a file
+# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
+# network: {config: disabled}
+"""
+
 
 class Distro(distros.Distro):
     hostname_conf_fn = "/etc/hostname"
@@ -59,7 +66,8 @@ class Distro(distros.Distro):
         self.osfamily = 'debian'
         self._net_renderer = eni.Renderer({
             'eni_path': self.network_conf_fn,
-            'links_prefix_path': self.links_prefix,
+            'eni_header': ENI_HEADER,
+            'links_prefix_path': None,
             'netrules_path': None,
         })
 
diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index 6959ad34..63e54f91 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -237,6 +237,11 @@ def _get_current_rename_info(check_downable=True):
 
 def _rename_interfaces(renames, strict_present=True, strict_busy=True,
                        current_info=None):
+
+    if not len(renames):
+        LOG.debug("no interfaces to rename")
+        return
+
     if current_info is None:
         current_info = _get_current_rename_info()
 
diff --git a/cloudinit/net/eni.py b/cloudinit/net/eni.py
index 2da13ffd..1c66319a 100644
--- a/cloudinit/net/eni.py
+++ b/cloudinit/net/eni.py
@@ -306,6 +306,7 @@ class Renderer(renderer.Renderer):
         if not config:
             config = {}
         self.eni_path = config.get('eni_path', 'etc/network/interfaces')
+        self.eni_header = config.get('eni_header', None)
         self.links_path_prefix = config.get(
             'links_path_prefix', 'etc/systemd/network/50-cloud-init-')
         self.netrules_path = config.get(
@@ -442,7 +443,8 @@ class Renderer(renderer.Renderer):
     def render_network_state(self, target, network_state):
         fpeni = os.path.join(target, self.eni_path)
         util.ensure_dir(os.path.dirname(fpeni))
-        util.write_file(fpeni, self._render_interfaces(network_state))
+        header = self.eni_header if self.eni_header else ""
+        util.write_file(fpeni, header + self._render_interfaces(network_state))
 
         if self.netrules_path:
             netrules = os.path.join(target, self.netrules_path)