Add concat and remove for interfaces.d

Change-Id: Ia97c5a79c5298f24aca6ca9148ce48546f3bcb70

README.rst

@@ -847,6 +847,25 @@ OpenVswitch Bridges
             use_interfaces:
             - eth1
 
+Concatinating and removing interface files
+
+Debian based distributions have `/etc/network/interfaces.d/` directory, where
+you can store configuration of network interfaces in separate files. You can
+concatinate the files to the defined destination when needed, this operation
+removes the file from the `/etc/network/interfaces.d/`. If you just need to
+remove iface files, you can use the `remove_iface_files` key.
+
+.. code-block:: yaml
+
+    linux:
+      network:
+        concat_iface_files:
+        - src: '/etc/network/interfaces.d/50-cloud-init.cfg'
+          dst: '/etc/network/interfaces'
+        remove_iface_files:
+        - '/etc/network/interfaces.d/90-custom.cfg'
+
+
 DHCP client configuration
 
 None of the keys is mandatory, include only those you really need. For full list

linux/network/interface.sls

@@ -20,6 +20,32 @@ linux_network_bridge_pkgs:
 
 {%- endif %}
 
+{%- for f in network.get('concat_iface_files', []) %}
+
+{%- if salt['file.file_exists'](f.src) %}
+
+append_{{ f.src }}_{{ f.dst }}:
+  file.append:
+    - name: {{ f.dst }}
+    - source: {{ f.src }}
+
+remove_appended_{{ f.src }}:
+  file.absent:
+    - name: {{ f.src }}
+
+{%- endif %}
+
+{%- endfor %}
+
+{%- for f in network.get('remove_iface_files', []) %}
+
+remove_iface_file_{{ f }}:
+  file.absent:
+    - name: {{ f }}
+
+{%- endfor %}
+
+
 {%- for interface_name, interface in network.interface.iteritems() %}
 
 {%- set interface_name = interface.get('name', interface_name) %}