cloud-init: T5190: Added Cloud-init pre-configurator

Added a new service that starts before Cloud-init, waits for all network
interfaces initialization, and if requested by config, checks which interfaces
can get configuration via DHCP server and creates a corresponding Cloud-init
network configuration.

This protects from two situations:

* when Cloud-init tries to get meta-data via eth0 (default and fallback variant
for any data source which depends on network), but the real network is connected
to another interface
* when Cloud-init starts simultaneously with udev and initializes the first
interface to get meta-data before it is renamed to eth0 by udev

1 files changed, 9 insertions, 0 deletions

diff --git a/data/templates/system/cloud_init_networking.j2 b/data/templates/system/cloud_init_networking.j2
new file mode 100644
index 000000000..52cce72f8
--- /dev/null
+++ b/data/templates/system/cloud_init_networking.j2
@@ -0,0 +1,9 @@
+network:
+  version: 2
+  ethernets:
+{% for iface in ifaces_list %}
+    {{ iface['name'] }}:
+      dhcp4: true
+      match:
+        macaddress: "{{ iface['mac'] }}"
+{% endfor %}