#! /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 SSSDConfig
    # so we use our own copy of ipapython
    from distutils.sysconfig import get_python_lib
    sys.path.insert(0, "%s/%s" % (get_python_lib(), "ipaclient"))

    import os
    import time
    import socket
    import ldap
    import ldap.sasl
    import urlparse
    import base64
    import logging
    import tempfile
    import getpass
    import re
    from ipaclient import ipadiscovery
    from ipaclient.ipadiscovery import CACERT
    import ipaclient.ipachangeconf
    import ipaclient.ntpconf
    from ipapython.ipautil import run, user_input, CalledProcessError, file_exists, realm_to_suffix, convert_ldap_error
    import ipapython.services as ipaservices
    from ipapython import ipautil
    from ipapython import dnsclient
    from ipapython import sysrestore
    from ipapython import version
    from ipapython import certmonger
    from ipapython import errors
    from ipapython.config import IPAOptionParser
    from ipapython.rpcclient import IPAClient
    from ConfigParser import RawConfigParser
    from optparse import SUPPRESS_HELP, OptionGroup, OptionValueError
    from OpenSSL import crypto
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)

SUCCESS = 0
CLIENT_INSTALL_ERROR = 1
CLIENT_NOT_CONFIGURED = 2
CLIENT_ALREADY_CONFIGURED = 3
CLIENT_UNINSTALL_ERROR = 4 # error after restoring files/state

client_nss_nickname_format = 'IPA Machine Certificate - %s'

def parse_options():
    def validate_ca_cert_file_option(option, opt, value, parser):
        if not os.path.exists(value):
            raise OptionValueError("%s option '%s' does not exist" % (opt, value))
        if not os.path.isfile(value):
            raise OptionValueError("%s option '%s' is not a file" % (opt, value))
        if not os.path.isabs(value):
            raise OptionValueError("%s option '%s' is not an absolute file path" % (opt, value))

        try:
            cert = load_certificate_from_file(value)
        except Exception, e:
            raise OptionValueError("%s option '%s' is not a valid certificate file" % (opt, value))

        parser.values.ca_cert_file = value

    parser = IPAOptionParser(version=version.VERSION)

    basic_group = OptionGroup(parser, "basic options")
    basic_group.add_option("--domain", dest="domain", help="domain name")
    basic_group.add_option("--server", dest="server", help="IPA server", action="append")
    basic_group.add_option("--realm", dest="realm_name", help="realm name")
    basic_group.add_option("-p", "--principal", dest="principal",
                      help="principal to use to join the IPA realm"),
    basic_group.add_option("-w", "--password", dest="password", sensitive=True,
                      help="password to join the IPA realm (assumes bulk password unless principal is also set)"),
    basic_group.add_option("-W", dest="prompt_password", action="store_true",
                      default=False,
                      help="Prompt for a password to join the IPA realm"),
    basic_group.add_option("--mkhomedir", dest="mkhomedir",
                      action="store_true", default=False,
                      help="create home directories for users on their first login")
    basic_group.add_option("", "--hostname", dest="hostname",
                      help="The hostname of this server (FQDN). If specified, the hostname will be set and "
                           "the system configuration will be updated to persist over reboot. "
                           "By default a nodename result from uname(2) is used.")
    basic_group.add_option("--ntp-server", dest="ntp_server", help="ntp server to use")
    basic_group.add_option("-N", "--no-ntp", action="store_false",
                      help="do not configure ntp", default=True, dest="conf_ntp")
    basic_group.add_option("-f", "--force", dest="force", action="store_true",
                      default=False, help="force setting of LDAP/Kerberos conf")
    basic_group.add_option("-d", "--debug", dest="debug", action="store_true",
                      default=False, help="print debugging information")
    basic_group.add_option("-U", "--unattended", dest="unattended",
                      action="store_true",
                      help="unattended (un)installation never prompts the user")
    basic_group.add_option("--ca-cert-file", dest="ca_cert_file",
                           type="string", action="callback", callback=validate_ca_cert_file_option,
                           help="load the CA certificate from this file")
    # --on-master is used in ipa-server-install and ipa-replica-install
    # only, it isn't meant to be used on clients.
    basic_group.add_option("--on-master", dest="on_master", action="store_true",
                      help=SUPPRESS_HELP, default=False)
    parser.add_option_group(basic_group)

    sssd_group = OptionGroup(parser, "SSSD options")
    sssd_group.add_option("--permit", dest="permit",
                      action="store_true", default=False,
                      help="disable access rules by default, permit all access.")
    sssd_group.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.")
    sssd_group.add_option("--no-krb5-offline-passwords", dest="krb5_offline_passwords",
                      action="store_false", default=True,
                      help="Configure SSSD not to store user password when the server is offline")
    sssd_group.add_option("-S", "--no-sssd", dest="sssd",
                      action="store_false", default=True,
                      help="Do not configure the client to use SSSD for authentication")
    sssd_group.add_option("--preserve-sssd", dest="preserve_sssd",
                      action="store_true", default=False,
                      help="Preserve old SSSD configuration if possible")
    parser.add_option_group(sssd_group)

    uninstall_group = OptionGroup(parser, "uninstall options")
    uninstall_group.add_option("", "--uninstall", dest="uninstall", action="store_true",
                      default=False, help="uninstall an existing installation. The uninstall can " \
                                          "be run with --unattended option")
    parser.add_option_group(uninstall_group)

    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 log_service_error(name, action, error):
    logging.error("%s failed to %s: %s" % (name, action, str(error)))
    
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 isvalid_base64(data):
    """
    Validate the incoming data as valid base64 data or not.

    The character set must only include of a-z, A-Z, 0-9, + or / and
    be padded with = to be a length divisible by 4 (so only 0-2 =s are
    allowed). Its length must be divisible by 4. White space is
    not significant so it is removed.

    This doesn't guarantee we have a base64-encoded value, just that it
    fits the base64 requirements.
    """

    data = ''.join(data.split())

    if len(data) % 4 > 0 or \
        re.match('^[a-zA-Z0-9\+\/]+\={0,2}$', data) is None:
        return False
    else:
        return True

def get_cert_path(cert_path):
    """
    If a CA certificate is passed in on the command line, use that.

    Else if a CA file exists in CACERT then use that.

    Otherwise return None.
    """
    if cert_path is not None:
        return cert_path

    if os.path.exists(CACERT):
        return CACERT

    return None

def load_certificate_from_file(filename):
    """
    Using PyOpenSSL load a PEM certificate file and return an x509 object.
    """
    fd = open(filename, 'r')
    data = fd.read()
    fd.close()

    return crypto.load_certificate(crypto.FILETYPE_PEM, data)

def make_pem(data):
    """
    Convert a raw base64-encoded blob into something that looks like a PE
    file with lines split to 64 characters and proper headers.
    """
    pemcert = '\n'.join([data[x:x+64] for x in range(0, len(data), 64)])
    return '-----BEGIN CERTIFICATE-----\n' + \
    pemcert + \
    '\n-----END CERTIFICATE-----'

def write_certificate(dercert, filename):
    """
    Write the certificate to a file in PEM format.

    The incoming cert value must be DER-encoded.
    """
    try:
        fp = open(filename, 'w')
        # Handle the case where the cert is double-encoded in the IPA server
        while isvalid_base64(dercert):
            dercert = base64.b64decode(dercert)
        fp.write(make_pem(base64.b64encode(dercert)))
        fp.close()
    except (IOError, OSError), e:
        raise errors.FileError(reason=str(e))

def cert_summary(msg, cert, indent='    '):
    if msg:
        s = '%s\n' % msg
    else:
        s = ''
    s += '%sSubject:     %s\n' % (indent, str(cert.get_subject())[18:-2])
    s += '%sIssuer:      %s\n' % (indent, str(cert.get_issuer())[18:-2])

    return s

def emit_quiet(quiet, message):
    if not quiet:
        print message

def uninstall(options, env, quiet=False):

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

    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 "Refer to ipa-server-install for uninstallation."
        return CLIENT_NOT_CONFIGURED

    hostname = None
    was_sssd_configured = False
    try:
        sssdconfig = SSSDConfig.SSSDConfig()
        sssdconfig.import_config()
        domains = sssdconfig.list_active_domains()
        if len(domains) > 1:
            # There was more than IPA domain configured
            was_sssd_configured = True
        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
    except Exception, e:
        # We were unable to read existing SSSD config. This might mean few things:
        # - sssd wasn't installed
        # - sssd was removed after install and before uninstall
        # - there are no active domains
        # in both cases we cannot continue with SSSD
        pass

    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:
            emit_quiet(quiet, "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
    messagebus = ipaservices.knownservices.messagebus
    try:
        messagebus.start()
    except Exception, e:
        log_service_error(messagebus.service_name, 'start', e)

    cmonger = ipaservices.knownservices.certmonger
    try:
        cmonger.start()
    except Exception, e:
        log_service_error(cmonger.service_name, 'start', e)

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

    try:
        cmonger.stop()
    except Exception, e:
        log_service_error(cmonger.service_name, 'stop', e)

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

    try:
        cmonger.disable()
    except Exception, e:
        emit_quiet(quiet, "Failed to disable automatic startup of the %s service" % (cmonger.service_name))
        logging.error("Failed to disable automatic startup of the %s service: %s" % (cmonger.service_name, str(e)))

    if not options.on_master and os.path.exists('/etc/ipa/default.conf'):
        emit_quiet(quiet, "Unenrolling client from IPA server")
        join_args = ["/usr/sbin/ipa-join", "--unenroll", "-h", hostname]
        if options.debug:
            join_args.append("-d")
            env['XMLRPC_TRACE_CURL'] = 'yes'
        (stdout, stderr, returncode) = run(join_args, raiseonerr=False, env=env)
        if returncode != 0:
            emit_quiet(quiet, "Unenrolling host failed: %s" % stderr)

    if os.path.exists('/etc/ipa/default.conf'):
        emit_quiet(quiet, "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:
            emit_quiet(quiet, "Failed to clean up /etc/krb5.keytab")
            logging.debug("Failed to remove Kerberos service principals: %s" % str(e))

    emit_quiet(quiet, "Disabling client Kerberos and LDAP configurations")
    was_sssd_installed = False
    if fstore.has_files():
        was_sssd_installed = fstore.has_file("/etc/sssd/sssd.conf")
    try:
        auth_config = ipaservices.authconfig()
        if statestore.has_state('authconfig'):
            # disable only those configurations that we enabled during install
            for conf in ('ldap', 'krb5', 'sssd', 'sssdauth', 'mkhomedir'):
                cnf = statestore.restore_state('authconfig', conf)
                if cnf:
                    auth_config.disable(conf)
        else:
            # There was no authconfig status store
            # It means the code was upgraded after original install
            # Fall back to old logic
            auth_config.disable("ldap").\
                        disable("krb5")
            if not(was_sssd_installed and was_sssd_configured):
                # assume there was sssd.conf before install and there were more than one domain in it
                # In such case restoring sssd.conf will require us to keep SSSD running
                auth_config.disable("sssd").\
                            disable("sssdauth")
            auth_config.disable("mkhomedir")

        auth_config.add_option("update")
        auth_config.execute()
    except Exception, e:
        emit_quiet(quiet, "Failed to remove krb5/LDAP configuration. " +str(e))
        return CLIENT_INSTALL_ERROR

    if fstore.has_files():
        emit_quiet(quiet, "Restoring client configuration files")
        fstore.restore_all_files()

    old_hostname = statestore.restore_state('network','hostname')
    if old_hostname is not None and old_hostname != hostname:
        try:
            ipautil.run(['/bin/hostname', old_hostname])
        except CalledProcessError, e:
            print >>sys.stderr, "Failed to set this machine hostname to %s (%s)." % (old_hostname, str(e))

    nscd = ipaservices.knownservices.nscd
    if nscd.is_installed():
        try:
            nscd.restart()
        except:
            emit_quiet(quiet, "Failed to restart the %s daemon" % (nscd.service_name))

        try:
            nscd.enable()
        except:
            emit_quiet(quiet, "Failed to configure automatic startup of the %s daemon" % (nscd.service_name))
    else:
        # this is optional service, just log
        logging.info("%s daemon is not installed, skip configuration" % (nscd.service_name))

    nslcd = ipaservices.knownservices.nslcd
    if nslcd.is_installed():
        try:
            nslcd.stop()
        except:
            emit_quiet(quiet, "Failed to stop the %s daemon" % (nslcd.service_name))

        try:
            nslcd.disable()
        except:
            emit_quiet(quiet, "Failed to disable automatic startup of the %s daemon" % (nslcd.service_name))
    else:
        # this is optional service, just log
        logging.info("%s daemon is not installed, skip configuration" % (nslcd.service_name))

    ntp_configured = statestore.has_state('ntp')
    if ntp_configured:
        ntp_enabled = statestore.restore_state('ntp', 'enabled')
        ntp_step_tickers = statestore.restore_state('ntp', 'step-tickers')
        restored = False

        try:
            # Restore might fail due to file missing in backup
            # the reason for it might be that freeipa-client was updated
            # to this version but not unenrolled/enrolled again
            # In such case it is OK to fail
            restored = fstore.restore_file("/etc/ntp.conf")
            restored |= fstore.restore_file("/etc/sysconfig/ntpd")
            if ntp_step_tickers:
               restored |= fstore.restore_file("/etc/ntp/step-tickers")
        except:
            pass

        if not ntp_enabled:
           ipaservices.knownservices.ntpd.stop()
           ipaservices.knownservices.ntpd.disable()
        else:
           if restored:
               ipaservices.knownservices.ntpd.restart()

    if was_sssd_installed and was_sssd_configured:
        # SSSD was installed before our installation, config now is restored, restart it
        emit_quiet(quiet, "The original configuration of SSSD included other domains than IPA-based one.")
        emit_quiet(quiet, "Original configuration file is restored, restarting SSSD service.")
        sssd = ipaservices.service('sssd')
        sssd.restart()

    if not options.unattended:
        emit_quiet(quiet, "The original nsswitch.conf configuration has been restored.")
        emit_quiet(quiet, "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:
                    emit_quiet(quiet, "Reboot command failed to exceute. " + str(e))
                    return CLIENT_UNINSTALL_ERROR

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

    return 0

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[0]},
               {'name':'xmlrpc_uri', 'type':'option', 'value':'https://%s/ipa/xml' % ipautil.format_netloc(cli_server[0])},
               {'name':'enable_ra', 'type':'option', 'value':'True'}]

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

    target_fname = '/etc/ipa/default.conf'
    fstore.backup_file(target_fname)
    ipaconf.newConf(target_fname, opts)
    os.chmod(target_fname, 0644)

    return 0

def disable_ra():
    """Set the enable_ra option in /etc/ipa/default.conf to False

    Note that api.env will retain the old value (it is readonly).
    """
    parser = RawConfigParser()
    parser.read('/etc/ipa/default.conf')
    parser.set('global', 'enable_ra', 'False')
    fp = open('/etc/ipa/default.conf', 'w')
    parser.write(fp)
    fp.close()

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://'+ipautil.format_netloc(cli_server[0])})
    else:
        opts.append({'name':'nss_srv_domain', 'type':'option', 'value':cli_domain})

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

    ret = (0, None, None)
    files = []
    # 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)
                files.append(filename)
            except Exception, e:
                print "Creation of %s: %s" % (filename, str(e))
                return (1, 'LDAP', filename)

    if files:
        return (0, 'LDAP', ', '.join(files))
    return ret

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://'+ipautil.format_netloc(cli_server[0])})
    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, None, None)

    nslcd = ipaservices.knownservices.nslcd
    if nslcd.is_installed():
        try:
            nslcd.restart()
        except Exception, e:
            log_service_error(nslcd.service_name, 'restart', e)

        try:
            nslcd.enable()
        except Exception, e:
            print "Failed to configure automatic startup of the %s daemon" % (nslcd.service_name)
            logging.error("Failed to enable automatic startup of the %s daemon: %s" % (nslcd.service_name, str(e)))
    else:
        logging.debug("%s daemon is not installed, skip configuration" % (nslcd.service_name))
        return (0, None, None)

    return (0, 'NSLCD', '/etc/nslcd.conf')

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://'+ipautil.format_netloc(cli_server[0])},
            {'name':'empty', 'type':'empty'}]

    # Errors raised by this should be caught by the caller
    ldapconf.changeConf("/etc/ldap.conf", opts)
    print "Changed configuration of /etc/ldap.conf to use hardcoded server name: " +cli_server[0]

    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
    kropts = []
    if not dnsok or not cli_kdc or options.force:
        #[realms]
        for server in cli_server:
            kropts.append({'name':'kdc', 'type':'option', 'value':ipautil.format_netloc(server, 88)})
            kropts.append({'name':'master_kdc', 'type':'option', 'value':ipautil.format_netloc(server, 88)})
            kropts.append({'name':'admin_server', 'type':'option', 'value':ipautil.format_netloc(server, 749)})
        kropts.append({'name':'default_domain', 'type':'option', 'value':cli_domain})
    else:
        kropts = []
    kropts.append({'name':'pkinit_anchors', 'type':'option', 'value':'FILE:%s' % CACERT})
    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'})

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

    krbconf.newConf(filename, opts)
    os.chmod(filename, 0644)

    return 0

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

    messagebus = ipaservices.knownservices.messagebus
    try:
        messagebus.start()
    except Exception, e:
        log_service_error(messagebus.service_name, 'start', e)

    # Ensure that certmonger has been started at least once to generate the
    # cas files in /var/lib/certmonger/cas.
    cmonger = ipaservices.knownservices.certmonger
    try:
        cmonger.restart()
    except Exception, e:
        log_service_error(cmonger.service_name, 'restart', e)

    if options.hostname:
        # It needs to be stopped if we touch them
        try:
            cmonger.stop()
        except Exception, e:
            log_service_error(cmonger.service_name, 'stop', 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:
        cmonger.restart()
    except Exception, e:
        print "Failed to start the %s daemon" % (cmonger.service_name)
        print "Automatic certificate management will not be available"
        log_service_error(cmonger.service_name, 'restart', e)
        started = False

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

    # Request our host cert
    if remote_env['enable_ra']:
        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:
                logging.debug("%s request for host certificate failed",
                    cmonger.service_name)
                print "%s request for host certificate failed" % (cmonger.service_name)
    else:
        logging.debug("An RA is not configured on the server. Not requesting host certificate.")
        print "An RA is not configured on the server. Not requesting host certificate."

def configure_sssd_conf(fstore, cli_realm, cli_domain, cli_server, options):
    try:
        sssdconfig = SSSDConfig.SSSDConfig()
        sssdconfig.import_config()
    except Exception, e:
        if os.path.exists("/etc/sssd/sssd.conf") and options.preserve_sssd:
            # SSSD config is in place but we are unable to read it
            # In addition, we are instructed to preserve it
            # This all means we can't use it and have to bail out
            print "SSSD config exists but cannot be parsed: %s" % (str(e))
            print "Correct errors in /etc/sssd/sssd.conf and re-run installation"
            logging.error("Failed to parse SSSD configuration and was instructed to preserve existing SSSD config: %s" % (str(e)))
            return 1

        # SSSD configuration does not exist or we are not asked to preserve it, create new one
        # We do make new SSSDConfig instance because IPAChangeConf-derived classes have no
        # means to reset their state and ParseError exception could come due to parsing
        # error from older version which cannot be upgraded anymore, leaving sssdconfig
        # instance practically unusable
        # Note that we already backed up sssd.conf before going into this routine
        if type(e) is IOError:
            print "New SSSD config will be created."
        else:
            # It was not IOError so it must have been parsing error
            print "Unable to parse existing SSSD config. As option --preserve-sssd was not specified, new config will override the old one."
            print "The old /etc/sssd/sssd.conf is backed up and will be restored during uninstall."
            logging.error("Unable to parse existing SSSD config and --preserve-sssd was not specified: %s" % (str(e)))
        logging.info("New SSSD config will be created")
        del sssdconfig
        sssdconfig = SSSDConfig.SSSDConfig()
        sssdconfig.new_config()

    try:
        domain = sssdconfig.new_domain(cli_domain)
    except SSSDConfig.DomainAlreadyExistsError:
        print "Domain %s is already configured in existing SSSD config, creating a new one." % cli_domain
        print "The old /etc/sssd/sssd.conf is backed up and will be restored during uninstall."
        logging.debug("Domain %s is already configured in existing SSSD config, creating a new one." % cli_domain)
        del sssdconfig
        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' % ', '.join(cli_server))
    else:
        # the master should only use itself for Kerberos
        domain.set_option('ipa_server', cli_server[0])
    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', CACERT)

    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)
    try:
        s.connect((server, 389))
        addr, port = s.getsockname()
    except socket.gaierror:
        s = socket.socket(socket.AF_INET6, socket.SOCK_STREAM, socket.IPPROTO_TCP)
        s.connect((server, 389))
        addr, port, foo, bar = 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)

    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/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)
    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 get_ca_cert_from_file(url):
    '''
    Get the CA cert from a user supplied file and write it into the
    CACERT file.

    Raises errors.NoCertificateError if unable to read cert.
    Raises errors.FileError if unable to write cert.
    '''

    # pylint: disable=E1101
    try:
        (scheme, netloc, path, params, query, fragment) = urlparse.urlparse(url, 'file')
    except Exception, e:
        raise errors.FileError(reason="unable to parse file url '%s'" % (url))

    if scheme != 'file':
        raise errors.FileError(reason="url is not a file scheme '%s'" % (url))

    filename = path

    if not os.path.exists(filename):
        raise errors.FileError(reason="file '%s' does not exist" % (filename))

    if not os.path.isfile(filename):
        raise errors.FileError(reason="file '%s' is not a file" % (filename))

    logging.debug("trying to retrieve CA cert from file %s", filename)
    try:
        cert = load_certificate_from_file(filename)
    except Exception, e:
        raise errors.NoCertificateError(entry=filename)

    try:
        write_certificate(crypto.dump_certificate(crypto.FILETYPE_ASN1, cert), CACERT)
    except Exception, e:
        raise errors.FileError(reason =
            u"cannot write certificate file '%s': %s" % (CACERT, e))

def get_ca_cert_from_http(url, ca_file, warn=True):
    '''
    Use HTTP to retrieve the CA cert and write it into the CACERT file.
    This is insecure and should be avoided.

    Raises errors.NoCertificateError if unable to retrieve and write cert.
    '''

    if warn:
        logging.warning("Downloading the CA certificate via HTTP, " +
                            "this is INSECURE")

    logging.debug("trying to retrieve CA cert via HTTP from %s", url)
    try:

        run(["/usr/bin/wget", "-O", ca_file, url])
    except CalledProcessError, e:
        raise errors.NoCertificateError(entry=url)

def get_ca_cert_from_ldap(url, basedn, ca_file):
    '''
    Retrieve th CA cert from the LDAP server by binding to the
    server with GSSAPI using the current Kerberos credentials.
    Write the retrieved cert into the CACERT file.

    Raises errors.NoCertificateError if cert is not found.
    Raises errors.NetworkError if LDAP connection can't be established.
    Raises errors.LDAPError for any other generic LDAP error.
    Raises errors.OnlyOneValueAllowed if more than one cert is found.
    Raises errors.FileError if unable to write cert.
    '''

    ca_cert_attr = 'cAcertificate;binary'
    dn = 'CN=CAcert, CN=ipa, CN=etc, %s' % basedn

    SASL_GSSAPI = ldap.sasl.sasl({},'GSSAPI')

    logging.debug("trying to retrieve CA cert via LDAP from %s", url)

    conn = ldap.initialize(url)
    try:
        conn.sasl_interactive_bind_s('', SASL_GSSAPI)
        result = conn.search_st(str(dn), ldap.SCOPE_BASE, 'objectclass=pkiCA',
                                [ca_cert_attr], timeout=10)
    except ldap.NO_SUCH_OBJECT, e:
        logging.debug("get_ca_cert_from_ldap() error: %s",
                          convert_ldap_error(e))
        raise errors.NoCertificateError(entry=url)

    except ldap.SERVER_DOWN, e:
        logging.debug("get_ca_cert_from_ldap() error: %s",
                          convert_ldap_error(e))
        raise errors.NetworkError(uri=url, error=str(e))
    except Exception, e:
        logging.debug("get_ca_cert_from_ldap() error: %s",
                          convert_ldap_error(e))
        raise errors.LDAPError(str(e))

    if len(result) != 1:
        raise errors.OnlyOneValueAllowed(attr=ca_cert_attr)

    attrs = result[0][1]
    try:
        der_cert = attrs[ca_cert_attr][0]
    except KeyError:
        raise errors.NoCertificateError(entry=ca_cert_attr)

    try:
        write_certificate(der_cert, ca_file)
    except Exception, e:
        raise errors.FileError(reason =
            u"cannot write certificate file '%s': %s" % (ca_file, e))

def validate_new_ca_cert(existing_ca_cert, ca_file, ask, override=False):

    try:
        new_ca_cert = load_certificate_from_file(ca_file)
    except Exception, e:
        raise errors.FileError(reason =
            "Unable to read new ca cert '%s': %s" % (ca_file, e))

    if existing_ca_cert is None:
        logging.info(
            cert_summary("Successfully retrieved CA cert", new_ca_cert))
        return

    if crypto.dump_certificate(crypto.FILETYPE_ASN1, existing_ca_cert) != crypto.dump_certificate(crypto.FILETYPE_ASN1, existing_ca_cert):
        logging.warning(
            "The CA cert available from the IPA server does not match the\n"
            "local certificate available at %s" % CACERT)
        logging.warning(
            cert_summary("Existing CA cert:", existing_ca_cert))
        logging.warning(
            cert_summary("Retrieved CA cert:", new_ca_cert))
        if override:
            logging.warning("Overriding existing CA cert\n")
        elif not ask or not user_input(
                "Do you want to replace the local certificate with the CA\n"
                "certificate retrieved from the IPA server?", True):
            raise errors.CertificateInvalidError(name='Retrieved CA')
    else:
        logging.debug(
                "Existing CA cert and Retrieved CA cert are identical")
        os.remove(ca_file)


def get_ca_cert(fstore, options, server, basedn):
    '''
    Examine the different options and determine a method for obtaining
    the CA cert.

    If successful the CA cert will have been written into CACERT.

    Raises errors.NoCertificateError if not successful.

    The logic for determining how to load the CA cert is as follow:

    In the OTP case (not -p and -w):

    1. load from user supplied cert file
    2. else load from HTTP

    In the 'user_auth' case ((-p and -w) or interactive):

    1. load from user supplied cert file
    2. load from LDAP using SASL/GSS/Krb5 auth
       (provides mutual authentication, integrity and security)
    3. if LDAP failed and interactive ask for permission to
       use insecure HTTP (default: No)

    In the unattended case:

    1. load from user supplied cert file
    2. load from HTTP if --force specified else fail

    In all cases if HTTP is used emit warning message
    '''

    ca_file = CACERT + ".new"

    def ldap_url():
        return urlparse.urlunparse(('ldap', ipautil.format_netloc(server),
                                   '', '', '', ''))

    def file_url():
        return urlparse.urlunparse(('file', '', options.ca_cert_file,
                                   '', '', ''))

    def http_url():
        return urlparse.urlunparse(('http', ipautil.format_netloc(server),
                                   '/ipa/config/ca.crt', '', '', ''))


    interactive = not options.unattended
    otp_auth = options.principal is None and options.password is not None
    existing_ca_cert = None

    if options.ca_cert_file:
        url = file_url()
        try:
            get_ca_cert_from_file(url)
        except Exception, e:
            logging.debug(e)
            raise errors.NoCertificateError(entry=url)
        logging.debug("CA cert provided by user, use it!")
    else:
        if os.path.exists(CACERT):
            if os.path.isfile(CACERT):
                try:
                    existing_ca_cert = load_certificate_from_file(CACERT)
                except Exception, e:
                    raise errors.FileError(reason=u"Unable to load existing" +
                                           " CA cert '%s': %s" % (CACERT, e))
            else:
                raise errors.FileError(reason=u"Existing ca cert '%s' is " +
                                       "not a plain file" % (CACERT))

        if otp_auth:
            if existing_ca_cert:
                logging.info("OTP case, CA cert preexisted, use it")
            else:
                url = http_url()
                override = not interactive
                if interactive and not user_input(
                    "Do you want download the CA cert from " + url + " ?\n"
                    "(this is INSECURE)", False):
                    raise errors.NoCertificateError(message=u"HTTP certificate"
                            " download declined by user")
                try:
                    get_ca_cert_from_http(url, ca_file, override)
                except Exception, e:
                    logging.debug(e)
                    raise errors.NoCertificateError(entry=url)

                try:
                    validate_new_ca_cert(existing_ca_cert, ca_file,
                                         False, override)
                except Exception, e:
                    os.unlink(ca_file)
                    raise
        else:
            # Auth with user credentials
            url = ldap_url()
            try:
                get_ca_cert_from_ldap(url, basedn, ca_file)
                try:
                    validate_new_ca_cert(existing_ca_cert,
                                         ca_file, interactive)
                except Exception, e:
                    os.unlink(ca_file)
                    raise
            except errors.NoCertificateError, e:
                logging.debug(str(e))
                url = http_url()
                if existing_ca_cert:
                    logging.warning(
                        "Unable to download CA cert from LDAP\n"
                        "but found preexisting cert, using it.\n")
                elif interactive and not user_input(
                    "Unable to download CA cert from LDAP.\n"
                    "Do you want download the CA cert form " + url + "?\n"
                    "(this is INSECURE)", False):
                    raise errors.NoCertificateError(message=u"HTTP "
                                "certificate download declined by user")
                elif not interactive and not options.force:
                    logging.error(
                        "In unattended mode without a One Time Password "
                        "(OTP) or without --ca-cert-file\nYou must specify"
                        " --force to retrieve the CA cert using HTTP")
                    raise errors.NoCertificateError(message=u"HTTP "
                                "certificate download requires --force")
                else:
                    try:
                        get_ca_cert_from_http(url, ca_file)
                    except Exception, e:
                        logging.debug(e)
                        raise errors.NoCertificateError(entry=url)
                    try:
                        validate_new_ca_cert(existing_ca_cert,
                                             ca_file, interactive)
                    except Exception, e:
                        os.unlink(ca_file)
                        raise
            except Exception, e:
                logging.debug(str(e))
                raise errors.NoCertificateError(entry=url)


        # We should have a cert now, move it to the canonical place
        if os.path.exists(ca_file):
            os.rename(ca_file, CACERT)
        elif existing_ca_cert is None:
            raise errors.InternalError(u"expected CA cert file '%s' to "
                                       u"exist, but it's absent" % (ca_file))


    # Make sure the file permissions are correct
    try:
        os.chmod(CACERT, 0644)
    except Exception, e:
        raise errors.FileError(reason=u"Unable set permissions on ca "
                               u"cert '%s': %s" % (CACERT, e))


def install(options, env, fstore, statestore):
    dnsok = False

    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:
        print "One of password and principal are required."
        return CLIENT_INSTALL_ERROR

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

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

    # Do discovery on the first server passed in, we'll do sanity checking
    # on any others
    ret = ds.search(domain=options.domain, servers=options.server, hostname=hostname, ca_cert_path=get_cert_path(options.ca_cert_file))

    if options.server and ret != 0:
        # There is no point to continue with installation as server list was
        # passed as a fixed list of server and thus we cannot discover any
        # better result
        logging.error("Failed to verify that %s is an IPA Server.",
                ', '.join(options.server))
        logging.error("This may mean that the remote server is not up "
            "or is not reachable due to network or firewall settings.")
        return CLIENT_INSTALL_ERROR

    if ret == ipadiscovery.BAD_HOST_CONFIG:
        print >>sys.stderr, "Can't get the fully qualified name of this host"
        print >>sys.stderr, "Check that the client is properly configured"
        return CLIENT_INSTALL_ERROR
    if ret == ipadiscovery.NOT_FQDN:
        print >>sys.stderr, "%s is not a fully-qualified hostname" % hostname
        return CLIENT_INSTALL_ERROR
    if ret in (ipadiscovery.NO_LDAP_SERVER, ipadiscovery.NOT_IPA_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 CLIENT_INSTALL_ERROR
        else:
            print "DNS discovery failed to determine your DNS domain"
            cli_domain = [user_input("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, servers=options.server, hostname=hostname, ca_cert_path=get_cert_path(options.ca_cert_file))

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

    if ret in (ipadiscovery.NO_LDAP_SERVER, ipadiscovery.NOT_IPA_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 CLIENT_INSTALL_ERROR
        else:
            print "DNS discovery failed to find the IPA Server"
            cli_server = user_input("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, servers=cli_server, hostname=hostname, ca_cert_path=get_cert_path(options.ca_cert_file))
    else:
        # Only set dnsok to True if we were not passed in one or more servers
        # and if DNS discovery actually worked.
        if not options.server:
            (server, domain) = ds.check_domain(ds.domain, set())
            if server and domain:
                logging.debug("DNS validated, enabling discovery")
                dnsok = True
            else:
                logging.debug("DNS discovery failed, disabling discovery")
        else:
            logging.debug("Using servers from command line, disabling DNS discovery")

    if not cli_server:
        cli_server = ds.servers
        if options.server:
            logging.debug("will use provided server: %s", ', '.join(options.server))
        elif ds.server:
            logging.debug("will use discovered server: %s", cli_server[0])

    if ret == ipadiscovery.NOT_IPA_SERVER:
        print >>sys.stderr, "%s is not an IPA v2 Server." % cli_server[0]
        logging.debug("%s is not an IPA v2 Server." % cli_server[0])
        return CLIENT_INSTALL_ERROR

    if ret == ipadiscovery.NO_ACCESS_TO_LDAP:
        print "Warning: Anonymous access to the LDAP server is disabled."
        print "Proceeding without strict verification."
        print "Note: This is not an error if anonymous access has been explicitly restricted."
        ret = 0

    if ret == ipadiscovery.NO_TLS_LDAP:
        print "Warning: The LDAP server requires TLS is but we do not have the CA."
        print "Proceeding without strict verification."
        ret = 0

    if ret != 0:
        print >>sys.stderr, "Failed to verify that "+cli_server[0]+" 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 CLIENT_INSTALL_ERROR

    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:
        if not options.server:
            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 CLIENT_INSTALL_ERROR

    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 CLIENT_INSTALL_ERROR

    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: "+', '.join(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 CLIENT_INSTALL_ERROR

    if options.hostname and not options.on_master:
        # configure /etc/sysconfig/network to contain the hostname we set.
        # skip this step when run by ipa-server-install as it always configures
        # hostname if different from system hostname
        ipaservices.backup_and_replace_hostname(fstore, statestore, options.hostname)

    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)

    if not options.on_master:
        nolog = tuple()
        # First test out the kerberos configuration
        try:
            # Attempt to sync time with IPA server.
            # We assume that NTP servers are discoverable through SRV records in the DNS
            # If that fails, we try to sync directly with IPA server, assuming it runs NTP
            print 'Synchronizing time with KDC...'
            ntp_servers = ipautil.parse_items(ds.ipadnssearchntp(cli_domain))
            synced_ntp = False
            if len(ntp_servers) > 0:
                for s in ntp_servers:
                   synced_ntp = ipaclient.ntpconf.synconce_ntp(s)
                   if synced_ntp:
                       break
            if not synced_ntp:
                synced_ntp = ipaclient.ntpconf.synconce_ntp(cli_server[0])
            if not synced_ntp:
                print "Unable to sync time with IPA NTP server, assuming the time is in sync."
            (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=False, options=options, filename=krb_name):
                print "Test kerberos configuration failed"
                return CLIENT_INSTALL_ERROR
            env['KRB5_CONFIG'] = krb_name
            join_args = ["/usr/sbin/ipa-join", "-s", cli_server[0], "-b", realm_to_suffix(cli_realm)]
            if options.debug:
                join_args.append("-d")
                env['XMLRPC_TRACE_CURL'] = 'yes'
            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:
                        try:
                            stdin = getpass.getpass("Password for %s: " % principal)
                        except EOFError:
                            stdin = None
                        if not stdin:
                            print "Password must be provided for %s. " % \
                                principal
                            return CLIENT_INSTALL_ERROR
                    else:
                        if sys.stdin.isatty():
                            print "Password must be provided in non-interactive mode.\nThis can be done via echo password | ipa-client-install ... or\nwith the -w option."
                            return CLIENT_INSTALL_ERROR
                        else:
                            stdin = sys.stdin.readline()

                (stderr, stdout, returncode) = run(["kinit", principal], raiseonerr=False, stdin=stdin, env=env)
                print ""
                if returncode != 0:
                    print stdout
                    return CLIENT_INSTALL_ERROR
            elif options.password:
                nolog = (options.password,)
                join_args.append("-w")
                join_args.append(options.password)
            elif options.prompt_password:
                if options.unattended:
                    print "Password must be provided in non-interactive mode"
                    return CLIENT_INSTALL_ERROR
                try:
                    password = getpass.getpass("Password: ")
                except EOFError:
                    password = None
                if not password:
                    print "Password must be provided."
                    return CLIENT_INSTALL_ERROR
                join_args.append("-w")
                join_args.append(password)
                nolog = (password,)

            # Get the CA certificate
            try:
                os.environ['KRB5_CONFIG'] = env['KRB5_CONFIG']
                get_ca_cert(fstore, options, cli_server[0], cli_basedn)
                del os.environ['KRB5_CONFIG']
            except Exception, e:
                logging.error("Cannot obtain CA certificate\n%s", e)
                return CLIENT_INSTALL_ERROR

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

            if returncode != 0:
                print >>sys.stderr, "Joining realm failed: %s" % stderr,
                if not options.force:
                    return CLIENT_INSTALL_ERROR
                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()

            if options.principal is not None:
                (stderr, stdout, returncode) = run(["kdestroy"], raiseonerr=False, env=env)

            # Obtain the TGT. We do it with the temporary krb5.conf, so that
            # only the KDC we're installing under is contacted.
            # Other KDCs might not have replicated the principal yet.
            # Once we have the TGT, it's usable on any server.
            env['KRB5CCNAME'] = os.environ['KRB5CCNAME'] = CCACHE_FILE
            host_principal = 'host/%s@%s' % (hostname, cli_realm)
            try:
                ipautil.run(['/usr/kerberos/bin/kinit', '-k', '-t', '/etc/krb5.keytab', host_principal],
                            env=env)
            except CalledProcessError, e:
                print >>sys.stderr, "Failed to obtain host TGT."
                # fail to obtain ticket makes it impossible to login and bind from sssd to LDAP,
                # abort installation and rollback changes
                return CLIENT_INSTALL_ERROR

        finally:
            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 CLIENT_INSTALL_ERROR
        print "Configured /etc/sssd/sssd.conf"

    # Add the CA to the default NSS database and trust it
    try:
        run(["/usr/bin/certutil", "-A", "-d", "/etc/pki/nssdb", "-n", "IPA CA", "-t", "CT,C,C", "-a", "-i", "/etc/ipa/ca.crt"])
    except CalledProcessError, e:
        print >>sys.stderr, "Failed to add CA to the default NSS database."
        return CLIENT_INSTALL_ERROR

    # 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 CLIENT_INSTALL_ERROR

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

        try:
            remote_env = IPAClient().forward('env')
            if remote_env is not None:
                if not remote_env['enable_ra']:
                    disable_ra()
                configure_certmonger(fstore, subject_base, cli_realm, hostname,
                                     options, remote_env)
        except Exception, e:
            logging.debug("Failed to configure certmonger: %s", e)

    #Try to update the DNS records, failure is not fatal
    if not options.on_master:
        client_dns(cli_server[0], hostname, options.dns_updates)

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

    #Name Server Caching Daemon. Disable for SSSD, use otherwise (if installed)
    nscd = ipaservices.knownservices.nscd
    if nscd.is_installed():
        try:
            if options.sssd:
                nscd_service_action = 'stop'
                nscd.stop()
            else:
                nscd_service_action = 'restart'
                nscd.restart()
        except:
            print >>sys.stderr, "Failed to %s the %s daemon" % (nscd_service_action, nscd.service_name)
            if not options.sssd:
                print >>sys.stderr, "Caching of users/groups will not be available"

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

    else:
        # this is optional service, just log
        if not options.sssd:
            logging.info("%s daemon is not installed, skip configuration" % (nscd.service_name))

    retcode, conf, filename = (0, None, None)
    # Modify nsswitch/pam stack
    auth_config = ipaservices.authconfig()
    if options.sssd:
        statestore.backup_state('authconfig', 'sssd', True)
        statestore.backup_state('authconfig', 'sssdauth', True)
        auth_config.enable("sssd").\
                    enable("sssdauth")
        message = "SSSD enabled"
        conf = 'SSSD'
    else:
        statestore.backup_state('authconfig', 'ldap', True)
        auth_config.enable("ldap").\
                    enable("forcelegacy")
        message = "LDAP enabled"

    if options.mkhomedir:
        statestore.backup_state('authconfig', 'mkhomedir', True)
        auth_config.enable("mkhomedir")

    auth_config.add_option("update")
    auth_config.execute()
    print message

    if not options.sssd:
        #Modify pam to add pam_krb5 only when sssd is not in use
        auth_config.reset()
        statestore.backup_state('authconfig', 'krb5', True)
        auth_config.enable("krb5").\
                    add_option("update").\
                    add_option("nostart")
        auth_config.execute()
        print "Kerberos 5 enabled"

    # Update non-SSSD LDAP configuration after authconfig calls as it would
    # change its configuration otherways
    if not options.sssd:
        for configurer in [configure_ldap_conf, configure_nslcd_conf]:
            (retcode, conf, filename) = configurer(fstore, cli_basedn, cli_realm, cli_domain, cli_server, dnsok, options)
            if retcode:
                return CLIENT_INSTALL_ERROR
            if conf:
                print "%s configured using configuration file(s) %s" % (conf, filename)

    #Check that nss is working properly
    if not options.on_master:
        n = 0
        found = False
        # Loop for up to 10 seconds to see if nss is working properly.
        # It can sometimes take a few seconds to connect to the remote provider.
        # Particulary, SSSD might take longer than 6-8 seconds.
        while n < 10 and not found:
            try:
                ipautil.run(["getent", "passwd", "admin"])
                found = True
            except Exception, e:
                time.sleep(1)
                n = n + 1

        if not found:
            print "Unable to find 'admin' user with 'getent passwd admin'!"
            if conf:
                print "Recognized configuration: %s" % (conf)
            else:
                print "Unable to reliably detect configuration. Check NSS setup manually."

            try:
                hardcode_ldap_server(cli_server)
            except Exception, e:
                print "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[0]
        ipaclient.ntpconf.config_ntp(ntp_server, fstore, statestore)
        print "NTP enabled"

    print "Client configuration complete."

    return 0

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

    env={"PATH":"/bin:/sbin:/usr/kerberos/bin:/usr/kerberos/sbin:/usr/bin:/usr/sbin"}

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

    global statestore
    statestore = sysrestore.StateFile('/var/lib/ipa-client/sysrestore')

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

    if fstore.has_files():
        print "IPA client is already configured on this system.\n" \
              "If you want to reinstall the IPA client, uninstall it first."
        return CLIENT_ALREADY_CONFIGURED

    rval = install(options, env, fstore, statestore)
    if rval == CLIENT_INSTALL_ERROR:
        if options.force:
            print "Installation failed. Force set so not rolling back changes."
        else:
            print "Installation failed. Rolling back changes."
            options.unattended = True
            uninstall(options, env, quiet=True)

    return rval

try:
    if __name__ == "__main__":
        sys.exit(main())
except SystemExit, e:
    sys.exit(e)
except KeyboardInterrupt:
    sys.exit(1)
except RuntimeError, e:
    sys.exit(e)
