#!/usr/bin/python2.6

# Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
#
#    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.

import ConfigParser
import os
import sys

import smf_include

from subprocess import CalledProcessError, Popen, PIPE, check_call


def start():
    """ retrieves the setting for 'zfs_volume_base' from Cinder's conf file in
    order to set it up properly for Cinder to use.

    """
    cinder_conf = "/etc/cinder/cinder.conf"
    if not os.path.exists(cinder_conf):
        print "%s doesn't exist" % cinder_conf
        return smf_include.SMF_EXIT_ERR_CONFIG

    parser = ConfigParser.ConfigParser()
    parser.read(cinder_conf)

    # retrieve the top-level dataset or just get the default (rpool/cinder)
    try:
        top_ds = parser.get("DEFAULT", "zfs_volume_base")
    except ConfigParser.NoOptionError:
        top_ds = "rpool/cinder"

    # look to see if the dataset exists
    cmd = ["/usr/sbin/zfs", "list", top_ds]
    try:
        check_call(cmd, stdout=PIPE, stderr=PIPE)
    except CalledProcessError as err:
        # the dataset doesn't exist, so go create it
        try:
            check_call(["/usr/sbin/zfs", "create", "-p", top_ds])
        except CalledProcessError as err:
            print "unable to create %s:  %s" % (top_ds, err)
            return smf_include.SMF_EXIT_ERR_CONFIG

    # get the mountpoint
    cmd = ["/usr/sbin/zfs", "get", "-H", "-o", "value", "mountpoint", top_ds]
    p = Popen(cmd, stdout=PIPE, stderr=PIPE)
    mountpoint, error = p.communicate()
    if p.returncode != 0:
        print "unable to determine mountpoint of %s:  %s" % (top_ds, error)
        return smf_include.SMF_EXIT_ERR_CONFIG

    p = Popen(["/usr/bin/ls", "-dv", mountpoint], stdout=PIPE, stderr=PIPE)
    output, error = p.communicate()

    if "user:cinder:add_subdirectory/append_data:allow" not in output:
        # set an ACL to all mountpoint access
        try:
            check_call(["/usr/bin/chmod",
                        "A+user:cinder:add_subdirectory:allow",
                        mountpoint.strip()])
        except CalledProcessError as err:
            print "ACL creation for mountpoint access of "
            print "%s to 'cinder' failed:  %s" % (top_ds, err)
            return smf_include.SMF_EXIT_ERR_CONFIG

    # set delegation
    cmd = ["/usr/sbin/zfs", "allow", "cinder",
           "clone,create,destroy,mount,snapshot", top_ds]
    try:
        check_call(cmd)
    except CalledProcessError as err:
        print "delegation of %s to 'cinder' failed:  %s" % (top_ds, err)
        return smf_include.SMF_EXIT_ERR_CONFIG

    return int(smf_include.SMF_EXIT_OK)

if __name__ == "__main__":
    os.putenv("LC_ALL", "C")
    smf_include.smf_main()