initial stab at growpart module

LP: #1136936

3 files changed, 182 insertions, 84 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)
diff --git a/cloudinit/config/cc_resizefs.py b/cloudinit/config/cc_resizefs.py
index 44b27933..51dead2f 100644
--- a/cloudinit/config/cc_resizefs.py
+++ b/cloudinit/config/cc_resizefs.py
@@ -51,89 +51,6 @@ RESIZE_FS_PREFIXES_CMDS = [
 NOBLOCK = "noblock"
 
 
-def get_mount_info(path, log):
-    # Use /proc/$$/mountinfo to find the device where path is mounted.
-    # This is done because with a btrfs filesystem using os.stat(path)
-    # does not return the ID of the device.
-    #
-    # Here, / has a device of 18 (decimal).
-    #
-    # $ stat /
-    #   File: '/'
-    #   Size: 234               Blocks: 0          IO Block: 4096   directory
-    # Device: 12h/18d   Inode: 256         Links: 1
-    # Access: (0755/drwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
-    # Access: 2013-01-13 07:31:04.358011255 +0000
-    # Modify: 2013-01-13 18:48:25.930011255 +0000
-    # Change: 2013-01-13 18:48:25.930011255 +0000
-    #  Birth: -
-    #
-    # Find where / is mounted:
-    #
-    # $ mount | grep ' / '
-    # /dev/vda1 on / type btrfs (rw,subvol=@,compress=lzo)
-    #
-    # And the device ID for /dev/vda1 is not 18:
-    #
-    # $ ls -l /dev/vda1
-    # brw-rw---- 1 root disk 253, 1 Jan 13 08:29 /dev/vda1
-    #
-    # So use /proc/$$/mountinfo to find the device underlying the
-    # input path.
-    path_elements = [e for e in path.split('/') if e]
-    devpth = None
-    fs_type = None
-    match_mount_point = None
-    match_mount_point_elements = None
-    mountinfo_path = '/proc/%s/mountinfo' % os.getpid()
-    for line in util.load_file(mountinfo_path).splitlines():
-        parts = line.split()
-
-        mount_point = parts[4]
-        mount_point_elements = [e for e in mount_point.split('/') if e]
-
-        # Ignore mounts deeper than the path in question.
-        if len(mount_point_elements) > len(path_elements):
-            continue
-
-        # Ignore mounts where the common path is not the same.
-        l = min(len(mount_point_elements), len(path_elements))
-        if mount_point_elements[0:l] != path_elements[0:l]:
-            continue
-
-        # Ignore mount points higher than an already seen mount
-        # point.
-        if (match_mount_point_elements is not None and
-            len(match_mount_point_elements) > len(mount_point_elements)):
-            continue
-
-        # Find the '-' which terminates a list of optional columns to
-        # find the filesystem type and the path to the device.  See
-        # man 5 proc for the format of this file.
-        try:
-            i = parts.index('-')
-        except ValueError:
-            log.debug("Did not find column named '-' in %s",
-                      mountinfo_path)
-            return None
-
-        # Get the path to the device.
-        try:
-            fs_type = parts[i + 1]
-            devpth = parts[i + 2]
-        except IndexError:
-            log.debug("Too few columns in %s after '-' column", mountinfo_path)
-            return None
-
-        match_mount_point = mount_point
-        match_mount_point_elements = mount_point_elements
-
-    if devpth and fs_type and match_mount_point:
-        return (devpth, fs_type, match_mount_point)
-    else:
-        return None
-
-
 def handle(name, cfg, _cloud, log, args):
     if len(args) != 0:
         resize_root = args[0]
@@ -150,7 +67,7 @@ def handle(name, cfg, _cloud, log, args):
 
     # TODO(harlowja): allow what is to be resized to be configurable??
     resize_what = "/"
-    result = get_mount_info(resize_what, log)
+    result = util.get_mount_info(resize_what, log)
     if not result:
         log.warn("Could not determine filesystem type of %s", resize_what)
         return
diff --git a/cloudinit/util.py b/cloudinit/util.py
index ffe844b2..1e9ca5d9 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -1586,3 +1586,86 @@ def expand_package_list(version_fmt, pkgs):
             raise RuntimeError("Invalid package type.")
 
     return pkglist
+
+
+def get_mount_info(path, log):
+    # Use /proc/$$/mountinfo to find the device where path is mounted.
+    # This is done because with a btrfs filesystem using os.stat(path)
+    # does not return the ID of the device.
+    #
+    # Here, / has a device of 18 (decimal).
+    #
+    # $ stat /
+    #   File: '/'
+    #   Size: 234               Blocks: 0          IO Block: 4096   directory
+    # Device: 12h/18d   Inode: 256         Links: 1
+    # Access: (0755/drwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
+    # Access: 2013-01-13 07:31:04.358011255 +0000
+    # Modify: 2013-01-13 18:48:25.930011255 +0000
+    # Change: 2013-01-13 18:48:25.930011255 +0000
+    #  Birth: -
+    #
+    # Find where / is mounted:
+    #
+    # $ mount | grep ' / '
+    # /dev/vda1 on / type btrfs (rw,subvol=@,compress=lzo)
+    #
+    # And the device ID for /dev/vda1 is not 18:
+    #
+    # $ ls -l /dev/vda1
+    # brw-rw---- 1 root disk 253, 1 Jan 13 08:29 /dev/vda1
+    #
+    # So use /proc/$$/mountinfo to find the device underlying the
+    # input path.
+    path_elements = [e for e in path.split('/') if e]
+    devpth = None
+    fs_type = None
+    match_mount_point = None
+    match_mount_point_elements = None
+    mountinfo_path = '/proc/%s/mountinfo' % os.getpid()
+    for line in load_file(mountinfo_path).splitlines():
+        parts = line.split()
+
+        mount_point = parts[4]
+        mount_point_elements = [e for e in mount_point.split('/') if e]
+
+        # Ignore mounts deeper than the path in question.
+        if len(mount_point_elements) > len(path_elements):
+            continue
+
+        # Ignore mounts where the common path is not the same.
+        l = min(len(mount_point_elements), len(path_elements))
+        if mount_point_elements[0:l] != path_elements[0:l]:
+            continue
+
+        # Ignore mount points higher than an already seen mount
+        # point.
+        if (match_mount_point_elements is not None and
+            len(match_mount_point_elements) > len(mount_point_elements)):
+            continue
+
+        # Find the '-' which terminates a list of optional columns to
+        # find the filesystem type and the path to the device.  See
+        # man 5 proc for the format of this file.
+        try:
+            i = parts.index('-')
+        except ValueError:
+            log.debug("Did not find column named '-' in %s",
+                      mountinfo_path)
+            return None
+
+        # Get the path to the device.
+        try:
+            fs_type = parts[i + 1]
+            devpth = parts[i + 2]
+        except IndexError:
+            log.debug("Too few columns in %s after '-' column", mountinfo_path)
+            return None
+
+        match_mount_point = mount_point
+        match_mount_point_elements = mount_point_elements
+
+    if devpth and fs_type and match_mount_point:
+        return (devpth, fs_type, match_mount_point)
+    else:
+        return None