support reading cloud_config from kernel command line

This allows the user to specify portions of the cloud-config
system config on the kernel command line.  values found on the
kernel command line have preference over those in system config.

The format is:
 cc:[ ]<yaml content here> [end_cc]
Where:
 'cc:' indicates the beginning of cloud config syntax
 [ ]   optionally followed by whitespace (which will be trimmed)
 <yaml content here> :
    this content is passed untouched to yaml
 end_cc:
    this is optional.  If no 'end_cc' tag is found, all data from
    the begin tag to the end of the command line is consumed

Multiple occurences of the cc:<data>end_cc will be joined with
carriage return before passing to yaml.
 
Any litteral '\n' (backslash followed by lower case 'n') are converted
to a carriage return.

The following are examples:
  cc: ssh_import_id: [smoser, kirkland]
  cc: ssh_import_id: [smoser, bob]\\nruncmd: [ [ ls, -l ], echo hi ] end_cc
  cc:ssh_import_id: [smoser] end_cc cc:runcmd: [ [ ls, -l ] ] end_cc

1 files changed, 4 insertions, 10 deletions

diff --git a/cloudinit/DataSourceNoCloud.py b/cloudinit/DataSourceNoCloud.py
index cd988d08..78c9c9c8 100644
--- a/cloudinit/DataSourceNoCloud.py
+++ b/cloudinit/DataSourceNoCloud.py
@@ -108,16 +108,10 @@ class DataSourceNoCloud(DataSource.DataSource):
 #  root=LABEL=uec-rootfs ro ds=nocloud
 def parse_cmdline_data(ds_id,fill,cmdline=None):
     if cmdline is None:
-        if 'DEBUG_PROC_CMDLINE' in os.environ:
-            cmdline = os.environ["DEBUG_PROC_CMDLINE"]
-        else:
-            cmdfp = open("/proc/cmdline")
-            cmdline = cmdfp.read().strip()
-            cmdfp.close()
-        cmdline = " %s " % cmdline.lower()
-
-        if not ( " %s " % ds_id in cmdline or " %s;" % ds_id in cmdline ):
-            return False
+        cmdline = util.get_cmdline()
+
+    if not ( " %s " % ds_id in cmdline or " %s;" % ds_id in cmdline ):
+        return False
 
     argline=""
     # cmdline can contain: