Add growlvm module

The module is aimed to extend logical volumes according to sizes
provided in image layout.

python growlvm.py --image-layout '{"home1": {"size": "1G", "resizefs": false}}'

The module support resizing for LVM volumes:

  * Only exact sizes specified in units M,G,T
  * % from total space on VG

Related-Prod: PROD-24537

Change-Id: Ia46a33855c44c6edba600efaaf4156f71668bc80
diff --git a/common/ubuntu_base.sh b/common/ubuntu_base.sh
index fbb475e..6bb6e1c 100644
--- a/common/ubuntu_base.sh
+++ b/common/ubuntu_base.sh
@@ -41,7 +41,9 @@
 # Pretty tools
 EXTRA_PKGS="${EXTRA_PKGS} byobu htop tmux tree vim-nox mc"
 # Common prerequisites
-EXTRA_PKGS="${EXTRA_PKGS} apt-transport-https libmnl0 python-apt python-m2crypto python-psutil acpid virt-what"
+# growlvm.py dependencies
+GROWLVM_PKGS="python-jsonschema python-yaml"
+EXTRA_PKGS="${EXTRA_PKGS} apt-transport-https libmnl0 python-apt python-m2crypto python-psutil acpid virt-what $GROWLVM_PKGS"
 apt-get -y install ${EXTRA_PKGS}
 
 # Cleanup old kernels, ensure latest is installed via metapackage package
diff --git a/ubuntu-16.04/files/scripts/growlvm.py b/ubuntu-16.04/files/scripts/growlvm.py
new file mode 100755
index 0000000..ae2ebd3
--- /dev/null
+++ b/ubuntu-16.04/files/scripts/growlvm.py
@@ -0,0 +1,306 @@
+#!/usr/bin/env python
+#
+# Copyright 2018 Mirantis, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+"""Growpart python module
+
+The module is aimed to extend logical volumes according to sizes provided
+in image layout.
+
+Example:
+  python growlvm --image-layout-file '/root/mylayout.yml'
+
+Attributes:
+  image-layout - json string with image layout. Supported params and
+                 description might be found in IMAGE_LAYOUT_SCHEMA
+
+"""
+
+__version__ = '1.0'
+
+import argparse
+import collections
+import yaml
+from jsonschema import validate
+import logging
+import os
+import re
+import subprocess
+import sys
+
+
+LOG = logging.getLogger(__name__)
+
+DECIMAL_REG = re.compile(r"(\d+)")
+
+IMAGE_LAYOUT_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Image partition layout",
+    "type": "object",
+    "patternProperties": {
+        ".*": {"$ref": "#/definitions/logical_volume_layout"}
+    },
+    "definitions": {
+        "logical_volume_layout": {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "description": "Logical Volume Name",
+                    "type": "string"
+                },
+                "size": {
+                    "description": (
+                        "Size of Logical volume in units of logical extents. "
+                        "The number might be volume size in units of "
+                        "megabytes. A size suffix of M for megabytes, G for "
+                        "gigabytes, T for terabytes, P for petabytes or E for "
+                        "exabytes is optional. The number can also be "
+                        "expressed as a percentage of the total space in the "
+                        "Volume Group with the suffix %VG. Percentage of the "
+                        "changeble values like free space is not supported."
+                        ),
+                },
+                "resizefs": {
+                    "description": (
+                        "Resize underlying filesystem together with the "
+                        "logical volume using fsadm(8)."
+                    ),
+                    "type": "boolean"
+                },
+                "vg": {
+                    "description": ("Volume group name to resize logical "
+                                    "volume on."),
+                    "type": "string"
+                }
+            },
+            "additionalProperties": False,
+            "required": ["size"]
+        }
+    },
+}
+
+
+def get_volume_groups_info(unit, vg):
+    cmd = ("vgs --noheadings -o vg_name,size,free,vg_extent_size --units %s "
+           "--separator ';' %s") % (unit, vg)
+    try:
+        output = subprocess.check_output(cmd, shell=True,
+                                         stderr=subprocess.STDOUT)
+    except subprocess.CalledProcessError as exc:
+        raise Exception("Failed to get volume group info", exc.output)
+
+    vgs = []
+    for line in output.splitlines():
+        parts = line.strip().split(';')
+        vgs.append({
+            'name': parts[0],
+            'size': int(DECIMAL_REG.match(parts[1]).group(1)),
+            'free': int(DECIMAL_REG.match(parts[2]).group(1)),
+            'ext_size': int(DECIMAL_REG.match(parts[3]).group(1))
+        })
+    return vgs
+
+
+def get_logical_volume_info(unit, vg):
+    cmd = ("lvs -a --noheadings --nosuffix -o lv_name,size,lv_attr --units %s "
+           "--separator ';' %s") % (unit, vg)
+    try:
+        output = subprocess.check_output(cmd, shell=True,
+                                         stderr=subprocess.STDOUT)
+    except subprocess.CalledProcessError as exc:
+        raise Exception("Failed to get volume info", exc.output)
+
+    lvs = []
+
+    for line in output.splitlines():
+        parts = line.strip().split(';')
+        lvs.append({
+            'name': parts[0].replace('[', '').replace(']', ''),
+            'size': int(DECIMAL_REG.match(parts[1]).group(1)),
+        })
+    return lvs
+
+
+def normalize_to_pe(size, pe):
+    """ Make sure requested size is multiply of PE
+
+    PE is gathered from system with honor of provided units,
+    when volume size is set in Gigabytes, PE (4mb default) will
+    be shown as 0.
+    """
+
+    if pe > 0:
+        return (size // pe + 1) * pe
+
+    return size
+
+
+def main():
+    logging.basicConfig(
+        format='%(asctime)s - %(levelname)s - %(message)s'
+    )
+    LOG.setLevel(logging.INFO)
+
+    parser = argparse.ArgumentParser(
+        description=('Grow lvm partitions and theirs filesystems to '
+                     'specified sizes.')
+    )
+
+    group = parser.add_mutually_exclusive_group(required=True)
+    group.add_argument(
+        '--image-layout',
+        help='json based image layout',
+    )
+    group.add_argument(
+        '--image-layout-file',
+        help='Path to file with image layout',
+    )
+    args = parser.parse_args()
+
+    if args.image_layout_file:
+        with open(args.image_layout_file) as f:
+            layout_info = yaml.load(f)
+    else:
+        layout_info = yaml.load(args.image_layout)
+
+    LOG.info("Validating provided layout.")
+    try:
+        validate(layout_info, IMAGE_LAYOUT_SCHEMA)
+    except Exception as e:
+        LOG.error("Validation of provided layout failed.")
+        raise e
+
+    for part_name, part_layout in layout_info.iteritems():
+
+        size_opt = '--size'
+        size_unit = 'm'
+
+        size = part_layout['size']
+        vg = part_layout.get('vg', 'vg0')
+        resizefs = part_layout.get('resizefs', True)
+
+        if size:
+            if '+' in size:
+                raise Exception("Setting relative size is not supported.")
+            # LVCREATE(8) -l --extents option with percentage
+            elif '%' in size:
+                size_parts = size.split('%', 1)
+                size_percent = int(size_parts[0])
+                if size_percent > 100:
+                    raise Exception(
+                        "Size percentage cannot be larger than 100%")
+                size_whole = size_parts[1]
+                if size_whole == 'ORIGIN':
+                    raise Exception("Snapshot Volumes are not supported")
+                elif size_whole not in ['VG']:
+                    raise Exception("Relative sizes are not supported.")
+                size_opt = '--extents'
+                size_unit = ''
+            else:
+                # LVCREATE(8) -L --size option unit
+                if size[-1].lower() in 'bskmgtpe':
+                    size_unit = size[-1].lower()
+                    size = size[0:-1]
+
+        # when no unit, megabytes by default
+        if size_opt == '--extents':
+            unit = 'm'
+        else:
+            unit = size_unit
+
+        vgs = get_volume_groups_info(unit, vg)
+        this_volume_group = vgs[0]
+        pe = this_volume_group['ext_size']
+
+        lvs = get_logical_volume_info(unit, vg)
+
+        LOG.info("Volume group info: %s", vgs)
+        LOG.info("Logical Volume info: %s", lvs)
+
+        this_volume = [v for v in lvs if v['name'] == part_name][0]
+
+        LOG.info("Using %s for volume: %s", size_opt, this_volume)
+        if size_opt == '--extents':
+            size_free = this_volume_group['free']
+            if size_whole == 'VG':
+                size_requested = normalize_to_pe(
+                    size_percent * this_volume_group['size'] / 100, pe)
+
+            LOG.info("Request %s size for volume %s",
+                     size_requested, this_volume)
+            if this_volume['size'] > size_requested:
+                raise Exception("Redusing volume size in not supported.")
+            elif this_volume['size'] < size_requested:
+                if (size_free > 0) and (('+' not in size) or
+                   (size_free >= (size_requested - this_volume['size']))):
+                    cmd = "lvextend "
+                else:
+                    raise Exception(
+                        ("Logical Volume %s could not be extended. Not "
+                         "enough free space left (%s%s required / %s%s "
+                         "available)"),
+                        this_volume['name'],
+                        size_requested - this_volume['size'],
+                        unit, size_free, unit
+                    )
+                if resizefs:
+                    cmd += "--resizefs "
+
+                cmd = "%s -%s %s%s %s/%s" % (
+                    cmd, size_opt, size, size_unit, vg, this_volume['name'])
+                try:
+                    LOG.debug("Executing command: %s", cmd)
+                    output = subprocess.check_output(
+                        cmd,
+                        shell=True,
+                        stderr=subprocess.STDOUT)
+                except subprocess.CalledProcessError as exc:
+                    raise Exception(
+                        "Failed to resize volume %s. Exception: %s" % (
+                            part_name, exc.output))
+            else:
+                LOG.info("No need to resize volume %s.", part_name)
+        else:
+            cmd = "lvresize "
+            if normalize_to_pe(int(size), pe) > this_volume['size']:
+                if resizefs:
+                    cmd += "--resizefs "
+                cmd = "%s -%s %s%s %s/%s" % (
+                    cmd, size_opt, size, size_unit, vg, this_volume['name'])
+                try:
+                    LOG.debug("Executing command: %s", cmd)
+                    output = subprocess.check_output(
+                        cmd,
+                        shell=True,
+                        stderr=subprocess.STDOUT)
+                except subprocess.CalledProcessError as exc:
+                    raise Exception(
+                        "Failed to resize volume %s. Exception: %s" % (
+                            part_name, exc.output))
+
+            elif normalize_to_pe(int(size), pe) == this_volume['size']:
+                LOG.info("No need to resize volume %s.", part_name)
+            else:
+                raise Exception(
+                    "Redusing size in not supported for provided layout.")
+
+
+if __name__ == '__main__':
+    try:
+        main()
+    except Exception as e:
+        LOG.exception("Failed to apply image layout: %s", e)
+        sys.exit(1)
diff --git a/ubuntu-16.04/template.json b/ubuntu-16.04/template.json
index 10f84df..3ac2970 100644
--- a/ubuntu-16.04/template.json
+++ b/ubuntu-16.04/template.json
@@ -101,6 +101,11 @@
       "type": "file",
       "source": "files/etc/",
       "destination": "/etc"
+    },
+    {
+      "type": "file",
+      "source": "files/scripts/",
+      "destination": "/usr/bin"
     }
   ],
   "post-processors": [