add 'resize_rootfs' cloud-config option.

ChangeLog

@@ -3,3 +3,4 @@
    syslog writing to it (LP: #704509)
  - rework of /var/lib/cloud layout
  - remove updates-check (LP: #653220)
+ - support resizing / on first boot (enabled by default)

cloudinit/CloudConfig/cc_resizefs.py

@@ -0,0 +1,54 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2011 Canonical Ltd.
+#
+#    Author: Scott Moser <scott.moser@canonical.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import cloudinit.util as util
+import subprocess
+import traceback
+
+def handle(name,cfg,cloud,log,args):
+    if len(args) != 0:
+        resize_root = False
+        if str(value).lower() in [ 'true', '1', 'on', 'yes']:
+            resize_root = True
+    else:
+        resize_root = util.get_cfg_option_bool(cfg,"resize_rootfs",False)
+
+    if not resize_root: return
+
+    log.debug("resizing root filesystem on first boot")
+
+    cmd = ['blkid', '-sTYPE', '-ovalue', '/dev/root']
+    try:
+        (fstype,err) = util.subp(cmd)
+    except Exception, e:
+        log.warn("Failed to get filesystem type via %s" % cmd)
+        raise
+
+    if fstype.startswith("ext"):
+        resize_cmd = [ 'resize2fs', '/dev/root' ]
+    elif fstype == "xfs":
+        resize_cmd = [ 'xfs_growfs', '/dev/root' ]
+    else:
+        log.debug("not resizing unknown filesystem %s" % fstype)
+        return
+
+    try:
+        (out,err) = util.subp(resize_cmd)
+    except Exception, e:
+        log.warn("Failed to resize filesystem (%s,%s)" % cmd)
+        raise
+

config/cloud.cfg

@@ -4,6 +4,7 @@ disable_root: 1
 preserve_hostname: False
 
 cloud_config_modules:
+ - resizefs
  - mounts
  - rsyslog
  - ssh-import-id

doc/examples/cloud-config.txt

@@ -275,3 +275,9 @@ rsyslog:
  - filename: 01-examplecom.conf
    content: |
    *.*   @@syslogd.example.com
+
+# resize_rootfs should the / filesytem be resized on first boot
+# this allows you to launch an instance with a larger disk / partition
+# and have the instance automatically grow / to accomoddate it
+# set to 'False' to disable
+resize_rootfs: True