initial dump of "sans-cloud" code (DataSourceNoCloud)

The new classes 'DataSourceNoCloud' and 'DataSourceNoCloudNet'
implement a way to get data from the filesystem, or (very minimal)
data from the kernel command line.  This allows the user to seed data to
these sources.

There are now 2 "cloud-init" jobs, cloud-init-local that runs on 
  mounted MOUNTPOINT=/
and 'cloud-init' that runs on 
  start on (mounted MOUNTPOINT=/ and net-device-up IFACE=eth0 and
     stopped cloud-init-local )

The idea is that cloud-init-local can actually function without network.

The last thing in this commit is "uncloud-init".
This tool can be invoked as 'init=/usr/lib/cloud-init/uncloud-init'
It will "uncloudify" things in the image, generally making it easier
to use for a simpler environment, and then it will exec /sbin/init.

1 files changed, 25 insertions, 6 deletions

diff --git a/cloud-init.py b/cloud-init.py
index ff70017f..11bf89af 100755
--- a/cloud-init.py
+++ b/cloud-init.py
@@ -30,6 +30,15 @@ def warn(str):
     sys.stderr.write(str)
 
 def main():
+    cmds = ( "start", "start-local" )
+    cmd = ""
+    if len(sys.argv) > 1:
+        cmd = sys.argv[1]
+
+    if not cmd in cmds:
+        sys.stderr.write("bad command %s. use one of %s\n" % (cmd, cmds))
+        sys.exit(1)
+
     now = time.strftime("%a, %d %b %Y %H:%M:%S %z")
     try:
        uptimef=open("/proc/uptime")
@@ -39,29 +48,39 @@ def main():
        warn("unable to open /proc/uptime\n")
        uptime = "na"
 
-    msg = "cloud-init running: %s. up %s seconds" % (now, uptime)
+    msg = "cloud-init %s running: %s. up %s seconds" % (cmd, now, uptime)
     sys.stderr.write(msg + "\n")
     sys.stderr.flush()
 
+    source_type = "all"
+    if cmd == "start-local":
+        source_type = "local"
+
     cloudinit.logging_set_from_cfg_file()
     log = logging.getLogger()
     log.info(msg)
 
     # cache is not instance specific, so it has to be purged
-    cloudinit.purge_cache()
+    # but we want 'start' to benefit from a cache if
+    # a previous start-local populated one
+    if cmd == "start-local":
+        cloudinit.purge_cache()
 
-    cloud = cloudinit.CloudInit()
+    cloud = cloudinit.CloudInit(source_type=source_type)
 
     try:
         cloud.get_data_source()
-    except Exception as e:
-        print e
-        sys.stderr.write("Failed to get instance data\n")
+    except cloudinit.DataSourceNotFoundException as e:
+        sys.stderr.write("no instance data found in %s\n" % cmd)
         sys.exit(1)
 
     # store the metadata
     cloud.update_cache()
 
+    msg = "found data source: %s" % cloud.datasource
+    sys.stderr.write(msg + "\n")
+    log.debug(msg)
+
     # parse the user data (ec2-run-userdata.py)
     try:
         cloud.sem_and_run("consume_userdata", "once-per-instance",