#! /usr/bin/python -E
# Authors: Simo Sorce <ssorce@redhat.com>
#          Karl MacMillan <kmacmillan@mentalrootkit.com>
#
# Copyright (C) 2007  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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/>.
#

try:
    import sys

    import os
    import time
    import socket
    import logging
    import tempfile
    import getpass
    from ipaclient import ipadiscovery
    import ipaclient.ipachangeconf
    import ipaclient.ntpconf
    from ipapython.ipautil import run, user_input, CalledProcessError, file_exists, package_installed_name
    from ipapython import ipautil
    from ipapython import dnsclient
    from ipapython import sysrestore
    from ipapython import version
    from ipapython import certmonger
    from ipapython.config import IPAOptionParser
    import SSSDConfig
    from ConfigParser import RawConfigParser
    from optparse import SUPPRESS_HELP
except ImportError:
    print >> sys.stderr, """\
There was a problem importing one of the required Python modules. The
error was:

    %s
""" % sys.exc_value
    sys.exit(1)

client_nss_nickname_format = 'IPA Machine Certificate - %s'

def parse_options():
    parser = IPAOptionParser(version=version.VERSION)
    parser.add_option("--domain", dest="domain", help="domain name")
    parser.add_option("--server", dest="server", help="IPA server")
    parser.add_option("--realm", dest="realm_name", help="realm name")
    parser.add_option("-f", "--force", dest="force", action="store_true",
                      default=False, help="force setting of LDAP/Kerberos conf")
    parser.add_option("-d", "--debug", dest="debug", action="store_true",
                      default=False, help="print debugging information")
    parser.add_option("-U", "--unattended", dest="unattended",
                      action="store_true",
                      help="unattended installation never prompts the user")
    parser.add_option("--ntp-server", dest="ntp_server", help="ntp server to use")
    parser.add_option("-S", "--no-sssd", action="store_false",
                      help="Do not configure the client to use SSSD for authentication", default=True, dest="sssd")
    parser.add_option("-N", "--no-ntp", action="store_false",
                      help="do not configure ntp", default=True, dest="conf_ntp")
    parser.add_option("-w", "--password", dest="password", sensitive=True,
                      help="password to join the IPA realm (assumes bulk password unless principal is also set)"),
    parser.add_option("-W", dest="prompt_password", action="store_true",
                      default=False,
                      help="Prompt for a password to join the IPA realm"),
    parser.add_option("-p", "--principal", dest="principal",
                      help="principal to use to join the IPA realm"),
    # --on-master is used in ipa-server-install and ipa-replica-install
    # only, it isn't meant to be used on clients.
    parser.add_option("--on-master", dest="on_master", action="store_true",
                      help=SUPPRESS_HELP, default=False)
    parser.add_option("--permit", dest="permit", action="store_true",
                      help="disable access rules by default, permit all access.", default=False)
    parser.add_option("--mkhomedir", dest="mkhomedir", action="store_true",
                      help="create home directories for users on their first login", default=False)
    parser.add_option("", "--uninstall", dest="uninstall", action="store_true",
                      default=False, help="uninstall an existing installation")
    parser.add_option("", "--hostname", dest="hostname",
                      help="The hostname of this server (FQDN). By default of nodename from uname(2) is used.")
    parser.add_option("", "--enable-dns-updates", dest="dns_updates", action="store_true", default=False,
                      help="Configures the machine to attempt dns updates when the ip address changes.")
    parser.add_option("--no-krb5-offline-passwords", dest="krb5_offline_passwords", action="store_false",
                      help="Configure SSSD not to store user password when the server is offline", default=True)

    options, args = parser.parse_args()
    safe_opts = parser.get_safe_opts(options)

    if (options.server and not options.domain):
        parser.error("--server cannot be used without providing --domain")

    return safe_opts, options

def logging_setup(options):
    # Always log everything (i.e., DEBUG) to the log
    # file.

    log_file = "/var/log/ipaclient-install.log"
    if options.uninstall:
        log_file = "/var/log/ipaclient-uninstall.log"

    old_umask = os.umask(077)
    logging.basicConfig(level=logging.DEBUG,
                        format='%(asctime)s %(levelname)s %(message)s',
                        filename=log_file,
                        filemode='w')
    os.umask(old_umask)

    console = logging.StreamHandler()
    # If the debug option is set, also log debug messages to the console
    if options.debug:
        console.setLevel(logging.DEBUG)
    else:
        # Otherwise, log critical and error messages
        console.setLevel(logging.ERROR)
    formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')
    console.setFormatter(formatter)
    logging.getLogger('').addHandler(console)

def nickname_exists(nickname):
        (sout, serr, returncode) = run(["/usr/bin/certutil", "-L", "-d", "/etc/pki/nssdb", "-n", nickname], raiseonerr=False)

        if returncode == 0:
            return True
        else:
            return False

def uninstall(options, env):

    if not fstore.has_files():
        print "IPA client is not configured on this system."
        return 2

    server_fstore = sysrestore.FileStore('/var/lib/ipa/sysrestore')
    if server_fstore.has_files() and not options.on_master:
        print "IPA client is configured as a part of IPA server on this system."
        print "Please refer to ipa-server-install for uninstallation."
        return 2

    sssdconfig = SSSDConfig.SSSDConfig()
    sssdconfig.import_config()
    domains = sssdconfig.list_active_domains()

    hostname = None
    for name in domains:
        domain = sssdconfig.get_domain(name)
        try:
            provider = domain.get_option('id_provider')
        except SSSDConfig.NoOptionError:
            continue
        if provider == "ipa":
            try:
                hostname = domain.get_option('ipa_hostname')
            except SSSDConfig.NoOptionError:
                continue

    if hostname is None:
        hostname = socket.getfqdn()

    client_nss_nickname = client_nss_nickname_format % hostname

    # Remove our host cert and CA cert
    if nickname_exists("IPA CA"):
        try:
            run(["/usr/bin/certutil", "-D", "-d", "/etc/pki/nssdb", "-n", "IPA CA"])
        except Exception, e:
            print "Failed to remove IPA CA from /etc/pki/nssdb: %s" % str(e)

    # Always start certmonger. We can't untrack something if it isn't
    # running
    try:
        ipautil.service_start('certmonger')
    except Exception, e:
        logging.error("certmonger failed to start: %s" % str(e))

    try:
        certmonger.stop_tracking('/etc/pki/nssdb', nickname=client_nss_nickname)
    except (CalledProcessError, RuntimeError), e:
        logging.error("certmonger failed to stop tracking certificate: %s" % str(e))

    if nickname_exists(client_nss_nickname):
        try:
            run(["/usr/bin/certutil", "-D", "-d", "/etc/pki/nssdb", "-n", client_nss_nickname])
        except Exception, e:
            print "Failed to remove %s from /etc/pki/nssdb: %s" % (client_nss_nickname, str(e))

    try:
        ipautil.service_stop('certmonger')
    except Exception, e:
        logging.error("certmonger failed to stop: %s" % str(e))

    # Remove any special principal names we added to the IPA CA helper
    certmonger.remove_principal_from_cas()

    try:
        ipautil.chkconfig_off('certmonger')
    except Exception, e:
        print "Failed to disable automatic startup of the certmonger daemon"
        logging.error("Failed to disable automatic startup of the certmonger daemon: %s" % str(e))

    if not options.on_master:
        print "Unenrolling client from IPA server"
        join_args = ["/usr/sbin/ipa-join", "--unenroll", "-h", hostname]
        (stdout, stderr, returncode) = run(join_args, raiseonerr=False, env=env)
        if returncode != 0:
            print "Unenrolling host failed: %s" % stderr

    print "Removing Kerberos service principals from /etc/krb5.keytab"
    try:
        parser = RawConfigParser()
        fp = open('/etc/ipa/default.conf', 'r')
        parser.readfp(fp)
        fp.close()
        realm = parser.get('global', 'realm')
        run(["/usr/sbin/ipa-rmkeytab", "-k", "/etc/krb5.keytab", "-r", realm])
    except Exception, e:
        print "Failed to clean up /etc/krb5.keytab"
        logging.error("Failed to remove Kerberos service principals: %s" % str(e))

    print "Disabling client Kerberos and LDAP configurations"
    try:
        run(["/usr/sbin/authconfig", "--disableldap", "--disablekrb5", "--disablesssd", "--disablesssdauth", "--disablemkhomedir", "--update"])
    except Exception, e:
        print "Failed to remove krb5/LDAP configuration. " +str(e)
        sys.exit(1)

    print "Restoring client configuration files"
    fstore.restore_all_files()

    if ipautil.service_is_installed('nscd'):
        try:
            ipautil.service_restart('nscd')
        except:
            print "Failed to restart start the NSCD daemon"

        try:
            ipautil.chkconfig_on('nscd')
        except:
            print "Failed to configure automatic startup of the NSCD daemon"
    else:
        # this is optional service, just log
        logging.info("NSCD daemon is not installed, skip configuration")

    if ipautil.service_is_installed('nslcd'):
        try:
            ipautil.service_stop('nslcd')
        except:
            print "Failed to stop the NSLCD daemon"

        try:
            ipautil.chkconfig_off('nslcd')
        except:
            print "Failed to disable automatic startup of the NSLCD daemon"
    else:
        # this is optional service, just log
        logging.info("NSLCD daemon is not installed, skip configuration")

    if not options.unattended:
        print "The original nsswitch.conf configuration has been restored."
        print "You may need to restart services or reboot the machine."
        if not options.on_master:
            if user_input("Do you want to reboot the machine?", False):
                try:
                    run(["/usr/bin/reboot"])
                except Exception, e:
                    print "Reboot command failed to exceute. " + str(e)
                    sys.exit(1)

    # Remove the IPA configuration file
    try:
        os.remove("/etc/ipa/default.conf")
    except:
        pass

def configure_ipa_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server):
    ipaconf = ipaclient.ipachangeconf.IPAChangeConf("IPA Installer")
    ipaconf.setOptionAssignment(" = ")
    ipaconf.setSectionNameDelimiters(("[","]"))

    opts = [{'name':'comment', 'type':'comment', 'value':'File modified by ipa-client-install'},
            {'name':'empty', 'type':'empty'}]

    #[global]
    defopts = [{'name':'basedn', 'type':'option', 'value':cli_basedn},
               {'name':'realm', 'type':'option', 'value':cli_realm},
               {'name':'domain', 'type':'option', 'value':cli_domain},
               {'name':'server', 'type':'option', 'value':cli_server},
               {'name':'xmlrpc_uri', 'type':'option', 'value':'https://%s/ipa/xml' % cli_server},
               {'name':'enable_ra', 'type':'option', 'value':'True'}]

    opts.append({'name':'global', 'type':'section', 'value':defopts})
    opts.append({'name':'empty', 'type':'empty'})

    fstore.backup_file("/etc/ipa/default.conf")
    ipaconf.newConf("/etc/ipa/default.conf", opts)

    return 0

def configure_ldap_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, dnsok, options):
    ldapconf = ipaclient.ipachangeconf.IPAChangeConf("IPA Installer")
    ldapconf.setOptionAssignment(" ")

    opts = [{'name':'comment', 'type':'comment', 'value':'File modified by ipa-client-install'},
            {'name':'empty', 'type':'empty'},
            {'name':'ldap_version', 'type':'option', 'value':'3'},
            {'name':'base', 'type':'option', 'value':cli_basedn},
            {'name':'empty', 'type':'empty'},
            {'name':'nss_base_passwd', 'type':'option', 'value':'cn=users,cn=accounts,'+cli_basedn+'?sub'},
            {'name':'nss_base_group', 'type':'option', 'value':'cn=groups,cn=accounts,'+cli_basedn+'?sub'},
            {'name':'nss_schema', 'type':'option', 'value':'rfc2307bis'},
            {'name':'nss_map_attribute', 'type':'option', 'value':'uniqueMember member'},
            {'name':'nss_initgroups_ignoreusers', 'type':'option', 'value':'root,dirsrv'},
            {'name':'empty', 'type':'empty'},
            {'name':'nss_reconnect_maxsleeptime', 'type':'option', 'value':'8'},
            {'name':'nss_reconnect_sleeptime', 'type':'option', 'value':'1'},
            {'name':'bind_timelimit', 'type':'option', 'value':'5'},
            {'name':'timelimit', 'type':'option', 'value':'15'},
            {'name':'empty', 'type':'empty'}]
    if not dnsok or options.force or options.on_master:
        if options.on_master:
            opts.append({'name':'uri', 'type':'option', 'value':'ldap://localhost'})
        else:
            opts.append({'name':'uri', 'type':'option', 'value':'ldap://'+cli_server})
    else:
        opts.append({'name':'nss_srv_domain', 'type':'option', 'value':cli_domain})

    opts.append({'name':'empty', 'type':'empty'})

    # Depending on the release and distribution this may exist in any
    # number of different file names, update what we find
    for filename in ['/etc/ldap.conf', '/etc/nss_ldap.conf', '/etc/libnss-ldap.conf', '/etc/pam_ldap.conf']:
        if file_exists(filename):
            try:
                fstore.backup_file(filename)
                ldapconf.newConf(filename, opts)
            except Exception, e:
                print "Creation of %s: %s" % (filename, str(e))
                return 1

    return 0

def configure_nslcd_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, dnsok, options):
    nslcdconf = ipaclient.ipachangeconf.IPAChangeConf("IPA Installer")
    nslcdconf.setOptionAssignment(" ")

    opts = [{'name':'comment', 'type':'comment', 'value':'File modified by ipa-client-install'},
            {'name':'empty', 'type':'empty'},
            {'name':'ldap_version', 'type':'option', 'value':'3'},
            {'name':'base', 'type':'option', 'value':cli_basedn},
            {'name':'empty', 'type':'empty'},
            {'name':'base passwd', 'type':'option', 'value':'cn=users,cn=accounts,'+cli_basedn},
            {'name':'base group', 'type':'option', 'value':'cn=groups,cn=accounts,'+cli_basedn},
            {'name':'map group', 'type':'option', 'value':'uniqueMember member'},
            {'name':'timelimit', 'type':'option', 'value':'15'},
            {'name':'empty', 'type':'empty'}]
    if not dnsok or options.force or options.on_master:
        if options.on_master:
            opts.append({'name':'uri', 'type':'option', 'value':'ldap://localhost'})
        else:
            opts.append({'name':'uri', 'type':'option', 'value':'ldap://'+cli_server})
    else:
        opts.append({'name':'uri', 'type':'option', 'value':'DNS'})

    opts.append({'name':'empty', 'type':'empty'})

    if file_exists('/etc/nslcd.conf'):
        try:
            fstore.backup_file('/etc/nslcd.conf')
            nslcdconf.newConf('/etc/nslcd.conf', opts)
        except Exception, e:
            print "Creation of %s: %s" % ('/etc/nslcd.conf', str(e))
            return 1

    if ipautil.service_is_installed('nslcd'):
        try:
            ipautil.service_restart('nslcd')
        except Exception, e:
            logging.error("nslcd failed to restart: %s" % str(e))

        try:
            ipautil.chkconfig_on('nslcd')
        except Exception, e:
            print "Failed to configure automatic startup of the NSLCD daemon"
            logging.error("Failed to enable automatic startup of the NSLCD daemon: %s" % str(e))
    else:
        logging.debug("NSLCD daemon is not installed, skip configuration")

    return 0

def hardcode_ldap_server(cli_server):
    """
    DNS Discovery didn't return a valid IPA server, hardcode a value into
    the file instead.
    """
    if not file_exists('/etc/ldap.conf'):
        return

    ldapconf = ipaclient.ipachangeconf.IPAChangeConf("IPA Installer")
    ldapconf.setOptionAssignment(" ")

    opts = [{'name':'uri', 'type':'option', 'action':'set', 'value':'ldap://'+cli_server},
            {'name':'empty', 'type':'empty'}]

    # Errors raised by this should be caught by the caller
    ldapconf.changeConf("/etc/ldap.conf", opts)

    return

def configure_krb5_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, cli_kdc, dnsok, options, filename):

    krbconf = ipaclient.ipachangeconf.IPAChangeConf("IPA Installer")
    krbconf.setOptionAssignment(" = ")
    krbconf.setSectionNameDelimiters(("[","]"))
    krbconf.setSubSectionDelimiters(("{","}"))
    krbconf.setIndent(("","  ","    "))

    opts = [{'name':'comment', 'type':'comment', 'value':'File modified by ipa-client-install'},
            {'name':'empty', 'type':'empty'}]

    #[libdefaults]
    libopts = [{'name':'default_realm', 'type':'option', 'value':cli_realm}]
    if not dnsok or not cli_kdc or options.force:
        libopts.append({'name':'dns_lookup_realm', 'type':'option', 'value':'false'})
        libopts.append({'name':'dns_lookup_kdc', 'type':'option', 'value':'false'})
    else:
        libopts.append({'name':'dns_lookup_realm', 'type':'option', 'value':'true'})
        libopts.append({'name':'dns_lookup_kdc', 'type':'option', 'value':'true'})
    libopts.append({'name':'rdns', 'type':'option', 'value':'false'})
    libopts.append({'name':'ticket_lifetime', 'type':'option', 'value':'24h'})
    libopts.append({'name':'forwardable', 'type':'option', 'value':'yes'})

    opts.append({'name':'libdefaults', 'type':'section', 'value':libopts})
    opts.append({'name':'empty', 'type':'empty'})

    #the following are necessary only if DNS discovery does not work
    if not dnsok or not cli_kdc or options.force:
        #[realms]
        kropts =[{'name':'kdc', 'type':'option', 'value':cli_server+':88'},
                 {'name':'admin_server', 'type':'option', 'value':cli_server+':749'},
                 {'name':'default_domain', 'type':'option', 'value':cli_domain}]
    else:
        kropts = []
    kropts.append({'name':'pkinit_anchors', 'type':'option', 'value':'FILE:/etc/ipa/ca.crt'})
    ropts = [{'name':cli_realm, 'type':'subsection', 'value':kropts}]

    opts.append({'name':'realms', 'type':'section', 'value':ropts})
    opts.append({'name':'empty', 'type':'empty'})

    #[domain_realm]
    dropts = [{'name':'.'+cli_domain, 'type':'option', 'value':cli_realm},
              {'name':cli_domain, 'type':'option', 'value':cli_realm}]
    opts.append({'name':'domain_realm', 'type':'section', 'value':dropts})
    opts.append({'name':'empty', 'type':'empty'})

    #[appdefaults]
    pamopts = [{'name':'debug', 'type':'option', 'value':'false'},
               {'name':'krb4_convert', 'type':'option', 'value':'false'}]
    appopts = [{'name':'pam', 'type':'subsection', 'value':pamopts}]
    opts.append({'name':'appdefaults', 'type':'section', 'value':appopts})

    logging.debug("Writing Kerberos configuration to %s:\n%s"
            % (filename, krbconf.dump(opts)))

    krbconf.newConf(filename, opts);

    return 0

def configure_certmonger(fstore, subject_base, cli_realm, hostname, options):
    started = True
    principal = 'host/%s@%s' % (hostname, cli_realm)

    # Ensure that certmonger has been started at least once to generate the
    # cas files in /var/lib/certmonger/cas.
    try:
        ipautil.service_restart('certmonger')
    except Exception, e:
        logging.error("certmonger failed to restart: %s" % str(e))

    if options.hostname:
        # It needs to be stopped if we touch them
        try:
            ipautil.service_stop('certmonger')
        except Exception, e:
            logging.error("certmonger failed to stop: %s" % str(e))
        # If the hostname is explicitly set then we need to tell certmonger
        # which principal name to use when requesting certs.
        certmonger.add_principal_to_cas(principal)

    try:
        ipautil.service_restart('certmonger')
    except Exception, e:
        print "Failed to start the certmonger daemon"
        print "Automatic certificate management will not be available"
        logging.error("certmonger failed to restart: %s" % str(e))
        started = False

    try:
        ipautil.chkconfig_on('certmonger')
    except Exception, e:
        print "Failed to configure automatic startup of the certmonger daemon"
        print "Automatic certificate management will not be available"
        logging.error("Failed to disable automatic startup of the certmonger daemon: %s" % str(e))

    # Request our host cert
    if started:
        client_nss_nickname = client_nss_nickname_format % hostname
        subject = 'CN=%s,%s' % (hostname, subject_base)
        try:
            run(["ipa-getcert", "request", "-d", "/etc/pki/nssdb", "-n", client_nss_nickname, "-N", subject, "-K", principal])
        except:
            print "certmonger request for host certificate failed"

def configure_sssd_conf(fstore, cli_realm, cli_domain, cli_server, options):
    sssdconfig = SSSDConfig.SSSDConfig()
    sssdconfig.new_config()

    domain = sssdconfig.new_domain(cli_domain)
    domain.add_provider('ipa', 'id')

    if not options.on_master:
        domain.set_option('ipa_server', '_srv_, %s' % cli_server)
    else:
        # the master should only use itself for Kerberos
        domain.set_option('ipa_server', cli_server)
    domain.set_option('ipa_domain', cli_domain)
    if options.hostname:
        domain.set_option('ipa_hostname', options.hostname)
    if cli_domain.lower() != cli_realm.lower():
        domain.set_option('krb5_realm', cli_realm)

    # Might need this if /bin/hostname doesn't return a FQDN
    #domain.set_option('ipa_hostname', 'client.example.com')

    domain.add_provider('ipa', 'auth')
    domain.add_provider('ipa', 'chpass')
    if not options.permit:
        domain.add_provider('ipa', 'access')
    else:
        domain.add_provider('permit', 'access')

    domain.set_option('cache_credentials', True)

    # SSSD will need TLS for checking if ipaMigrationEnabled attribute is set
    # Note that SSSD will force StartTLS because the channel is later used for
    # authentication as well if password migration is enabled. Thus set the option
    # unconditionally.
    domain.set_option('ldap_tls_cacert', '/etc/ipa/ca.crt')

    if options.dns_updates:
        domain.set_option('ipa_dyndns_update', True)
    if options.krb5_offline_passwords:
        domain.set_option('krb5_store_password_if_offline', True)

    domain.set_active(True)

    sssdconfig.save_domain(domain)
    sssdconfig.write("/etc/sssd/sssd.conf")

    return 0

def resolve_ipaddress(server):
    """ Connect to the server's LDAP port in order to determine what ip
        address this machine uses as "public" ip (relative to the server).
    """

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP)
    s.connect((server, 389))
    addr, port = s.getsockname()
    s.close()

    return addr

UPDATE_TEMPLATE_A = """
zone $ZONE.
update delete $HOSTNAME. IN A
send
update add $HOSTNAME. $TTL IN A $IPADDRESS
send
"""

UPDATE_TEMPLATE_AAAA = """
zone $ZONE.
update delete $HOSTNAME. IN AAAA
send
update add $HOSTNAME. $TTL IN AAAA $IPADDRESS
send
"""

UPDATE_FILE = "/etc/ipa/.dns_update.txt"
CCACHE_FILE = "/etc/ipa/.dns_ccache"

def update_dns(server, hostname):

    ip = resolve_ipaddress(server)
    princ = 'host/%s' % hostname

    sub_dict = dict(HOSTNAME=hostname,
                    IPADDRESS=ip,
                    TTL=1200,
                    ZONE='.'.join(hostname.split('.')[1:])
                )

    template = None
    if len(ip.split('.')) == 4:
        template = UPDATE_TEMPLATE_A
    elif len(ip.split(':')) > 1:
        template = UPDATE_TEMPLATE_AAAA

    if template is None:
        print >>sys.stderr, "Failed to determine machine's ip address."
        print >>sys.stderr, "Failed to update DNS A record."
        return

    update_txt = ipautil.template_str(template, sub_dict)

    logging.debug("Writing nsupdate commands to %s:\n%s"
            % (UPDATE_FILE, update_txt))

    update_fd = file(UPDATE_FILE, "w")
    update_fd.write(update_txt)
    update_fd.flush()
    update_fd.close()

    try:
        ipautil.run(['/usr/bin/kinit', '-k', '-t', '/etc/krb5.keytab', princ],
                    env={'KRB5CCNAME':CCACHE_FILE})
    except CalledProcessError, e:
        print >>sys.stderr, "Failed to obtain host TGT."

    try:
        ipautil.run(['/usr/bin/nsupdate', '-g', UPDATE_FILE],
                    env={'KRB5CCNAME':CCACHE_FILE})
        print "DNS server record set to: %s -> %s" % (hostname, ip)
    except CalledProcessError, e:
        print >>sys.stderr, "Failed to update DNS A record. (%s)" % str(e)

    try:
        os.remove(UPDATE_FILE)
        os.remove(CCACHE_FILE)
    except:
        pass

def client_dns(server, hostname, dns_updates=False):

    dns_ok = False

    # Check if the client has an A record registered in its name.
    rs = dnsclient.query(hostname+".", dnsclient.DNS_C_IN, dnsclient.DNS_T_A)
    if len([ rec for rec in rs if rec.dns_type is not dnsclient.DNS_T_SOA ]) > 0:
        dns_ok = True
    else:
        rs = dnsclient.query(hostname+".", dnsclient.DNS_C_IN, dnsclient.DNS_T_AAAA)
        if len([ rec for rec in rs if rec.dns_type is not dnsclient.DNS_T_SOA ]) > 0:
            dns_ok = True
        else:
            print "Warning: Hostname (%s) not found in DNS" % hostname

    if dns_updates or not dns_ok:
        update_dns(server, hostname)

def main():
    safe_options, options = parse_options()
    logging_setup(options)
    logging.debug('%s was invoked with options: %s' % (sys.argv[0], safe_options))
    logging.debug("missing options might be asked for interactively later\n")
    dnsok = False
    env={"PATH":"/bin:/sbin:/usr/kerberos/bin:/usr/kerberos/sbin:/usr/bin:/usr/sbin"}

    global fstore
    fstore = sysrestore.FileStore('/var/lib/ipa-client/sysrestore')

    if options.uninstall:
        return uninstall(options, env)

    if fstore.has_files():
        sys.exit("IPA client is already configured on this system.\n"
                + "If you want to reinstall the IPA client please uninstall it first.")

    cli_domain = None
    cli_server = None
    cli_realm = None
    cli_basedn = None
    subject_base = None

    if options.unattended and (options.password is None and options.principal is None and options.prompt_password is False) and not options.on_master:
        sys.exit("One of password and principal are required.")

    if options.hostname:
        hostname = options.hostname
    else:
        hostname = socket.getfqdn()
    if hostname != hostname.lower():
        sys.exit('Invalid hostname \'%s\', must be lower-case.' % hostname)

    # Create the discovery instance
    ds = ipadiscovery.IPADiscovery()

    ret = ds.search(domain=options.domain, server=options.server, hostname=hostname)

    if ret == ipadiscovery.BAD_HOST_CONFIG:
        print >>sys.stderr, "Can't get the fully qualified name of this host"
        print >>sys.stderr, "Please check that the client is properly configured"
        return ret
    if ret == ipadiscovery.NOT_FQDN:
        print >>sys.stderr, "%s is not a fully-qualified hostname" % hostname
        return ret
    if ret == ipadiscovery.NO_LDAP_SERVER or not ds.getDomainName():
        logging.debug("Domain not found")
        if options.domain:
            cli_domain = options.domain
        elif options.unattended:
            print >>sys.stderr, "Unable to discover domain, not provided on command line"
            return ret
        else:
            print "DNS discovery failed to determine your DNS domain"
            cli_domain = user_input("Please provide the domain name of your IPA server (ex: example.com)", allow_empty = False)
            logging.debug("will use domain: %s\n", cli_domain)
        ret = ds.search(domain=cli_domain, server=options.server, hostname=hostname)

    if not cli_domain:
        if ds.getDomainName():
            cli_domain = ds.getDomainName()
            logging.debug("will use domain: %s\n", cli_domain)

    if ret == ipadiscovery.NO_LDAP_SERVER or not ds.getServerName():
        logging.debug("IPA Server not found")
        if options.server:
            cli_server = options.server
        elif options.unattended:
            print >>sys.stderr, "Unable to find IPA Server to join"
            return ret
        else:
            print "DNS discovery failed to find the IPA Server"
            cli_server = user_input("Please provide your IPA server name (ex: ipa.example.com)", allow_empty = False)
            logging.debug("will use server: %s\n", cli_server)
        ret = ds.search(domain=cli_domain, server=cli_server, hostname=hostname)
    else:
        dnsok = True
    if not cli_server:
        if ds.getServerName():
            cli_server = ds.getServerName()
            logging.debug("will use server: %s\n", cli_server)

    if ret == ipadiscovery.NOT_IPA_SERVER:
        print >>sys.stderr, "%s is not an IPA v2 Server." % cli_server
        return ret
    if ret != 0:
        print >>sys.stderr, "Failed to verify that "+cli_server+" is an IPA Server."
        print >>sys.stderr, "This may mean that the remote server is not up or is not reachable"
        print >>sys.stderr, "due to network or firewall settings."
        return ret

    cli_kdc = ds.getKDCName()
    if dnsok and not cli_kdc:
        print >>sys.stderr, "DNS domain '%s' is not configured for automatic KDC address lookup." % ds.getRealmName().lower()
        print >>sys.stderr, "KDC address will be set to fixed value.\n"

    if dnsok:
        print "Discovery was successful!"
    elif not options.unattended:
        print "\nThe failure to use DNS to find your IPA server indicates that your"
        print "resolv.conf file is not properly configured.\n"
        print "Autodiscovery of servers for failover cannot work with this configuration.\n"
        print "If you proceed with the installation, services will be configured to always"
        print "access the discovered server for all operation and will not fail over to"
        print "other servers in case of failure.\n"
        if not user_input("Proceed with fixed values and no DNS discovery?", False):
            return ret

    if options.realm_name and options.realm_name != ds.getRealmName():
        if not options.unattended:
            print >>sys.stderr, "ERROR: The provided realm name: ["+options.realm_name+"] does not match with the discovered one: ["+ds.getRealmName()+"]\n"
        return -3

    cli_realm = ds.getRealmName()
    logging.debug("will use cli_realm: %s\n", cli_realm)
    cli_basedn = ds.getBaseDN()
    logging.debug("will use cli_basedn: %s\n", cli_basedn)
    subject_base = "O=%s" % ds.getRealmName()

    print "Hostname: "+hostname
    print "Realm: "+cli_realm
    print "DNS Domain: "+cli_domain
    print "IPA Server: "+cli_server
    print "BaseDN: "+cli_basedn

    print "\n"
    if not options.unattended and not user_input("Continue to configure the system with these values?", False):
        return 1

    if not options.unattended:
        if options.principal is None and options.password is None and options.prompt_password is False:
            options.principal = user_input("User authorized to enroll computers", allow_empty=False)
            logging.debug("will use principal: %s\n", options.principal)

    # Get the CA certificate
    try:
        # Remove anything already there so that wget doesn't use its
        # too-clever renaming feature
        os.remove("/etc/ipa/ca.crt")
    except:
        pass

    try:
        run(["/usr/bin/wget", "-O", "/etc/ipa/ca.crt", "http://%s/ipa/config/ca.crt" % cli_server])
    except CalledProcessError, e:
        sys.exit('Retrieving CA from %s failed.\n%s' % (cli_server, str(e)))

    if not options.on_master:
        # First test out the kerberos configuration
        try:
            (krb_fd, krb_name) = tempfile.mkstemp()
            os.close(krb_fd)
            if configure_krb5_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, cli_kdc, dnsok, options, krb_name):
                sys.exit("Test kerberos configuration failed")
            env['KRB5_CONFIG'] = krb_name
            join_args = ["/usr/sbin/ipa-join", "-s", cli_server]
            if options.debug:
                join_args.append("-d")
            if options.hostname:
                join_args.append("-h")
                join_args.append(options.hostname)
            if options.principal is not None:
                stdin = None
                principal = options.principal
                if principal.find('@') == -1:
                    principal = '%s@%s' % (principal, cli_realm)
                if options.password is not None:
                    stdin = options.password
                else:
                    if not options.unattended:
                        stdin = getpass.getpass("Password for %s: " % principal)
                        if not stdin:
                            sys.exit("Password must be provided for %s. " %
                                principal)
                    else:
                        if sys.stdin.isatty():
                            sys.exit("Password must be provided in non-interactive mode.\nThis can be done via echo password | ipa-client-install ... or\nwith the -w option.")
                        else:
                            stdin = sys.stdin.readline()

                (stderr, stdout, returncode) = run(["kinit", principal], raiseonerr=False, stdin=stdin, env=env)
                print ""
                if returncode != 0:
                    sys.exit(stdout)
            elif options.password:
                join_args.append("-w")
                join_args.append(options.password)
            elif options.prompt_password:
                if options.unattended:
                    sys.exit("Password must be provided in non-interactive mode")
                password = getpass.getpass("Password: ")
                join_args.append("-w")
                join_args.append(password)

            # Now join the domain
            (stdout, stderr, returncode) = run(join_args, raiseonerr=False, env=env)

            if returncode != 0:
                print >>sys.stderr, "Joining realm failed: %s" % stderr,
                if not options.force:
                    return 1
                print "  Use ipa-getkeytab to obtain a host principal for this server."
            else:
                print "Enrolled in IPA realm %s" % cli_realm

            start = stderr.find('Certificate subject base is: ')
            if start >= 0:
                start = start + 29
                subject_base = stderr[start:]
                subject_base = subject_base.strip()

        finally:
            if options.principal is not None:
                (stderr, stdout, returncode) = run(["kdestroy"], raiseonerr=False, env=env)
            os.remove(krb_name)
            os.remove(krb_name + ".ipabkp")

    # Configure ipa.conf
    if not options.on_master:
        configure_ipa_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server)
        print "Created /etc/ipa/default.conf"

    # Always back up sssd.conf. It gets updated by authconfig --enablekrb5.
    fstore.backup_file("/etc/sssd/sssd.conf")
    if options.sssd:
        if configure_sssd_conf(fstore, cli_realm, cli_domain, cli_server, options):
            return 1
        print "Configured /etc/sssd/sssd.conf"

    # Add the CA to the default NSS database and trust it
    run(["/usr/bin/certutil", "-A", "-d", "/etc/pki/nssdb", "-n", "IPA CA", "-t", "CT,C,C", "-a", "-i", "/etc/ipa/ca.crt"])

    # If on master assume kerberos is already configured properly.
    if not options.on_master:
        # Configure krb5.conf
        fstore.backup_file("/etc/krb5.conf")
        if configure_krb5_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, cli_kdc, dnsok, options, "/etc/krb5.conf"):
            return 1

        print "Configured /etc/krb5.conf for IPA realm " + cli_realm

        configure_certmonger(fstore, subject_base, cli_realm, hostname, options)

    #Try to update the DNS records, failure is not fatal
    if not options.on_master:
        client_dns(cli_server, hostname, options.dns_updates)

    #Name Server Caching Daemon. Disable for SSSD, use otherwise (if installed)
    if ipautil.service_is_installed("nscd"):
        if options.sssd:
            nscd_service_action = "stop"
            nscd_service_cmd = ipautil.service_stop
            nscd_chkconfig_cmd = ipautil.chkconfig_off
        else:
            nscd_service_action = "restart"
            nscd_service_cmd = ipautil.service_restart
            nscd_chkconfig_cmd = ipautil.chkconfig_on

        try:
            nscd_service_cmd('nscd')
        except:
            print >>sys.stderr, "Failed to %s the NSCD daemon" % nscd_service_action
            if not options.sssd:
                print >>sys.stderr, "Caching of users/groups will not be available"

        try:
            nscd_chkconfig_cmd('nscd')
        except:
            if not options.sssd:
                print >>sys.stderr, "Failed to configure automatic startup of the NSCD daemon"
                print >>sys.stderr, "Caching of users/groups will not be available after reboot"
	    else:
		print >>sys.stderr, "Failed to disable NSCD daemon. Please disable it manually."

    else:
        # this is optional service, just log
        logging.info("NSCD daemon is not installed, skip configuration")

    # Modify nsswitch/pam stack
    if options.sssd:
        cmd = ["/usr/sbin/authconfig", "--enablesssd", "--enablesssdauth", "--update"]
        message = "SSSD enabled"
    else:
        cmd = ["/usr/sbin/authconfig", "--enableldap", "--enableforcelegacy", "--update"]
        message = "LDAP enabled"

    if options.mkhomedir:
        cmd.append("--enablemkhomedir")
    run(cmd)
    print message

    #Modify pam to add pam_krb5
    run(["/usr/sbin/authconfig", "--enablekrb5", "--update", "--nostart"])
    print "Kerberos 5 enabled"

    # Update non-SSSD LDAP configuration after authconfig calls as it would
    # change its configuration otherways
    if not options.sssd:
        if configure_ldap_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, dnsok, options):
            return 1
        if configure_nslcd_conf(fstore, cli_basedn, cli_realm, cli_domain, cli_server, dnsok, options):
            return 1
        print "LDAP configured"

    #Check that nss is working properly
    if not options.on_master:
        n = 0
        found = False
        # Loop for up to 5 seconds to see if nss is working properly.
        # It can sometimes take a few seconds to connect to the remote
        # provider.
        while n < 5 and not found:
            try:
                run(["getent", "passwd", "admin"])
                found = True
            except Exception, e:
                time.sleep(1)
                n = n + 1

        if not found:
            package = package_installed_name(["nss-pam-ldapd","nss_ldap"])
            print "Unable to use DNS discovery! Recognized configuration: %s" % (package)
            print "Changing configuration to use hardcoded server name: " +cli_server

            try:
                hardcode_ldap_server(cli_server)
            except Exception, e:
                sys.exit("Adding hardcoded server name to /etc/ldap.conf failed: " + str(e))

    if options.conf_ntp and not options.on_master:
        if options.ntp_server:
            ntp_server = options.ntp_server
        else:
            ntp_server = cli_server
        ipaclient.ntpconf.config_ntp(ntp_server, fstore)
        print "NTP enabled"

    print "Client configuration complete."

    return 0

try:
    if __name__ == "__main__":
        if not os.getegid() == 0:
            sys.exit("\nYou must be root to run ipa-client-install.\n")

        sys.exit(main())
except SystemExit, e:
    sys.exit(e)
except KeyboardInterrupt:
    sys.exit(1)
except RuntimeError, e:
    sys.exit(e)