NoCloud: support seed of nocloud from smbios information

This allows the user to seed NoCloud in a trivial way from qemu/libvirt,
by using a stock image and passing a single command line flag.  No custom
command line, no filesystem modification, no bootstrap disk image.

This is particularly handy now that Ec2 backend is discouraged from use
under bug 1660385.

LP: #1691772

1 files changed, 12 insertions, 0 deletions

diff --git a/cloudinit/sources/DataSourceNoCloud.py b/cloudinit/sources/DataSourceNoCloud.py
index c68f6b8c..e641244d 100644
--- a/cloudinit/sources/DataSourceNoCloud.py
+++ b/cloudinit/sources/DataSourceNoCloud.py
@@ -43,6 +43,18 @@ class DataSourceNoCloud(sources.DataSource):
                   'network-config': None}
 
         try:
+            # Parse the system serial label from dmi. If not empty, try parsing
+            # like the commandline
+            md = {}
+            serial = util.read_dmi_data('system-serial-number')
+            if serial and load_cmdline_data(md, serial):
+                found.append("dmi")
+                mydata = _merge_new_seed(mydata, {'meta-data': md})
+        except Exception:
+            util.logexc(LOG, "Unable to parse dmi data")
+            return False
+
+        try:
             # Parse the kernel command line, getting data passed in
             md = {}
             if load_cmdline_data(md):