initial stab at growpart module

LP: #1136936

1 files changed, 98 insertions, 0 deletions

diff --git a/cloudinit/config/cc_growpart.py b/cloudinit/config/cc_growpart.py
new file mode 100644
index 00000000..f958cd53
--- /dev/null
+++ b/cloudinit/config/cc_growpart.py
@@ -0,0 +1,98 @@
+# 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 os.path
+import stat
+
+from cloudinit.settings import PER_ALWAYS
+from cloudinit import util
+
+frequency = PER_ALWAYS
+
+
+def device_part_info(devpath, log):
+    # convert an entry in /dev/ to parent disk and partition number
+
+    # input of /dev/vdb or /dev/disk/by-label/foo
+    # rpath is hopefully a real-ish path in /dev (vda, sdb..)
+    rpath = os.path.realpath(devpath)
+
+    bname = os.path.basename(rpath)
+    syspath = "/sys/class/block/%s" % bname
+
+    if not os.path.exists(syspath):
+        log.debug("%s had no syspath (%s)" % (devpath, syspath))
+        return None
+
+    ptpath = os.path.join(syspath, "partition")
+    if not os.path.exists(ptpath):
+        log.debug("%s not a partition" % devpath)
+        return None
+
+    ptnum = util.load_file(ptpath).rstrip()
+
+    # for a partition, real syspath is something like:
+    # /sys/devices/pci0000:00/0000:00:04.0/virtio1/block/vda/vda1
+    rsyspath = os.path.realpath(syspath)
+    disksyspath = os.path.dirname(rsyspath)
+
+    diskmajmin = util.load_file(os.path.join(disksyspath, "dev")).rstrip()
+    diskdevpath = os.path.realpath("/dev/block/%s" % diskmajmin)
+
+    # diskdevpath has something like 253:0
+    # and udev has put links in /dev/block/253:0 to the device name in /dev/
+    return (diskdevpath, ptnum)
+
+
+def handle(name, cfg, _cloud, log, args):
+    if len(args) != 0:
+        growroot = args[0]
+    else:
+        growroot = util.get_cfg_option_bool(cfg, "growroot", True)
+
+    if not growroot:
+        log.debug("Skipping module named %s, growroot disabled", name)
+        return
+
+    resize_what = "/"
+    result = util.get_mount_info(resize_what, log)
+    if not result:
+        log.warn("Could not determine filesystem type of %s" % resize_what)
+        return
+
+    (devpth, _fs_type, mount_point) = result
+
+    # Ensure the path is a block device.
+    if not stat.S_ISBLK(os.stat(devpth).st_mode):
+        log.debug("The %s device which was found for mount point %s for %s "
+                  "is not a block device" % (devpth, mount_point, resize_what))
+        return
+
+    result = device_part_info(devpth, log)
+    if not result:
+        log.debug("%s did not look like a partition" % devpth)
+
+    (disk, ptnum) = result
+
+    try:
+        (out, _err) = util.subp(["growpart", disk, ptnum], rcs=[0, 1])
+    except util.ProcessExecutionError as e:
+        log.warn("growpart failed: %s/%s" % (e.stdout, e.stderr))
+        return
+
+    log.debug("growpart said: %s" % out)