support reading network interface config from DataSourceNoCloud

document usage of DataSourceNoCloud from vfat or iso disk.

1 files changed, 39 insertions, 2 deletions

diff --git a/cloudinit/DataSourceNoCloud.py b/cloudinit/DataSourceNoCloud.py
index 6c744b82..1e28edbd 100644
--- a/cloudinit/DataSourceNoCloud.py
+++ b/cloudinit/DataSourceNoCloud.py
@@ -24,6 +24,7 @@ from cloudinit import seeddir as base_seeddir
 from cloudinit import log
 import cloudinit.util as util
 import errno
+import subprocess
 
 
 class DataSourceNoCloud(DataSource.DataSource):
@@ -31,6 +32,7 @@ class DataSourceNoCloud(DataSource.DataSource):
     userdata = None
     userdata_raw = None
     supported_seed_starts = ("/", "file://")
+    dsmode = "local"
     seed = None
     cmdline_id = "ds=nocloud"
     seeddir = base_seeddir + '/nocloud'
@@ -42,7 +44,7 @@ class DataSourceNoCloud(DataSource.DataSource):
 
     def get_data(self):
         defaults = {
-            "instance-id": "nocloud"
+            "instance-id": "nocloud", "dsmode": "net"
         }
 
         found = []
@@ -84,14 +86,20 @@ class DataSourceNoCloud(DataSource.DataSource):
             except OSError, e:
                 if e.errno != errno.ENOENT:
                     raise
+            except util.mountFailedError:
+                log.warn("Failed to mount %s when looking for seed" % dev)
 
         # there was no indication on kernel cmdline or data
         # in the seeddir suggesting this handler should be used.
         if len(found) == 0:
             return False
 
+        seeded_interfaces = None
+
         # the special argument "seedfrom" indicates we should
         # attempt to seed the userdata / metadata from its value
+        # its primarily value is in allowing the user to type less
+        # on the command line, ie: ds=nocloud;s=http://bit.ly/abcdefg
         if "seedfrom" in md:
             seedfrom = md["seedfrom"]
             seedfound = False
@@ -104,6 +112,9 @@ class DataSourceNoCloud(DataSource.DataSource):
                     (seedfrom, self.__class__))
                 return False
 
+            if 'network-interfaces' in md:
+                seeded_interfaces = self.dsmode
+
             # this could throw errors, but the user told us to do it
             # so if errors are raised, let them raise
             (md_seed, ud) = util.read_seeded(seedfrom, timeout=None)
@@ -114,10 +125,35 @@ class DataSourceNoCloud(DataSource.DataSource):
             found.append(seedfrom)
 
         md = util.mergedict(md, defaults)
+
+        # update the network-interfaces if metadata had 'network-interfaces'
+        # entry and this is the local datasource, or 'seedfrom' was used
+        # and the source of the seed was self.dsmode
+        # ('local' for NoCloud, 'net' for NoCloudNet')
+        if ('network-interfaces' in md and
+            (self.dsmode in ("local", seeded_interfaces))):
+            log.info("updating network interfaces from nocloud")
+
+            util.write_file("/etc/network/interfaces",
+                md['network-interfaces'])
+            try:
+                (out, err) = util.subp(['ifup', '--all'])
+                if len(out) or len(err):
+                    log.warn("ifup --all had stderr: %s" % err)
+
+            except subprocess.CalledProcessError as exc:
+                log.warn("ifup --all failed: %s" % (exc.output[1]))
+
         self.seed = ",".join(found)
         self.metadata = md
         self.userdata_raw = ud
-        return True
+
+        if md['dsmode'] == self.dsmode:
+            return True
+
+        log.debug("%s: not claiming datasource, dsmode=%s" %
+            (self, md['dsmode']))
+        return False
 
 
 # returns true or false indicating if cmdline indicated
@@ -166,6 +202,7 @@ class DataSourceNoCloudNet(DataSourceNoCloud):
     cmdline_id = "ds=nocloud-net"
     supported_seed_starts = ("http://", "https://", "ftp://")
     seeddir = base_seeddir + '/nocloud-net'
+    dsmode = "net"
 
 
 datasources = (