freeipa/client/ipa-client-automount

#!/usr/bin/python2 -E
#
# Authors:
#   Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2012  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/>.
#
# Configure the automount client for ldap.

from __future__ import print_function

import sys
import os
import time
import tempfile
import gssapi

import SSSDConfig
from six.moves.urllib.parse import urlsplit

from optparse import OptionParser
from ipalib import api, errors
from ipapython import sysrestore
from ipapython import ipautil
from ipaclient import ipadiscovery
from ipaclient import ipachangeconf
from ipapython.ipa_log_manager import root_logger, standard_logging_setup
from ipapython.dn import DN
from ipaplatform.constants import constants
from ipaplatform.tasks import tasks
from ipaplatform import services
from ipaplatform.paths import paths


def parse_options():
    usage = "%prog [options]\n"
    parser = OptionParser(usage=usage)
    parser.add_option("--server", dest="server", help="IPA server")
    parser.add_option("--location", dest="location", help="Automount location",
        default="default")
    parser.add_option("-S", "--no-sssd", dest="sssd",
                      action="store_false", default=True,
                      help="Do not configure the client to use SSSD for automount")
    parser.add_option("--debug", dest="debug", action="store_true",
        default=False, help="enable debugging")
    parser.add_option("-U", "--unattended", dest="unattended",
        action="store_true", default=False,
        help="unattended installation never prompts the user")
    parser.add_option("--uninstall", dest="uninstall", action="store_true",
        default=False, help="Unconfigure automount")

    options, args = parser.parse_args()
    return options, args

def wait_for_sssd():
    """
    It takes a bit for sssd to get going, lets loop until it is
    serving data.

    This function returns nothing.
    """
    n = 0
    found = False
    time.sleep(1)
    while n < 10 and not found:
        try:
            ipautil.run(["getent", "passwd", "admin@%s" % api.env.realm])
            found = True
        except Exception as e:
            time.sleep(1)
            n = n + 1

    # This should never happen but if it does, may as well warn the user
    if not found:
        err_msg = ("Unable to find 'admin' user with "
                   "'getent passwd admin@%s'!" % api.env.realm)
        root_logger.debug(err_msg)
        print(err_msg)
        print("This may mean that sssd didn't re-start properly after the configuration changes.")

def configure_xml(fstore):
    from lxml import etree

    fstore.backup_file(paths.AUTOFS_LDAP_AUTH_CONF)

    try:
        f = open(paths.AUTOFS_LDAP_AUTH_CONF, 'r')
        lines = f.read()
        f.close()

        saslconf = etree.fromstring(lines)
        element = saslconf.xpath('//autofs_ldap_sasl_conf')
        root = saslconf.getroottree()
    except IOError as e:
        root_logger.debug('Unable to open file %s' % e)
        root_logger.debug('Creating new from template')
        element = [etree.Element('autofs_ldap_sasl_conf')]
        root = element[0].getroottree()

    if len(element) != 1:
        raise RuntimeError('Unable to parse %s' % paths.AUTOFS_LDAP_AUTH_CONF)

    element[0].set('usetls', 'no')
    element[0].set('tlsrequired', 'no')
    element[0].set('authrequired', 'yes')
    element[0].set('authtype', 'GSSAPI')
    element[0].set('clientprinc', 'host/%s@%s' % (api.env.host, api.env.realm))

    newconf = open(paths.AUTOFS_LDAP_AUTH_CONF, 'w')
    try:
        root.write(newconf, pretty_print=True, xml_declaration=True, encoding='UTF-8')
        newconf.close()
    except IOError as e:
        print("Unable to write %s: %s" % (paths.AUTOFS_LDAP_AUTH_CONF, e))
    print("Configured %s" % paths.AUTOFS_LDAP_AUTH_CONF)

def configure_nsswitch(fstore, options):
    """
    Point automount to ldap in nsswitch.conf. This function is for non-SSSD
    setups only
    """
    fstore.backup_file(paths.NSSWITCH_CONF)

    conf = ipachangeconf.IPAChangeConf("IPA Installer")
    conf.setOptionAssignment(':')

    nss_value = ' files ldap'

    opts = [{'name':'automount', 'type':'option', 'action':'set', 'value':nss_value},
            {'name':'empty', 'type':'empty'}]

    conf.changeConf(paths.NSSWITCH_CONF, opts)

    print("Configured %s" % paths.NSSWITCH_CONF)

def configure_autofs_sssd(fstore, statestore, autodiscover, options):
    try:
        sssdconfig = SSSDConfig.SSSDConfig()
        sssdconfig.import_config()
        domains = sssdconfig.list_active_domains()
    except Exception as e:
        sys.exit(e)

    try:
        sssdconfig.new_service('autofs')
    except SSSDConfig.ServiceAlreadyExists:
        pass
    except SSSDConfig.ServiceNotRecognizedError:
        root_logger.error("Unable to activate the Autofs service in SSSD config.")
        root_logger.info(
            "Please make sure you have SSSD built with autofs support installed.")
        root_logger.info(
            "Configure autofs support manually in /etc/sssd/sssd.conf.")
        sys.exit("Cannot create the autofs service in sssd.conf")

    sssdconfig.activate_service('autofs')

    domain = None
    for name in domains:
        domain = sssdconfig.get_domain(name)
        try:
            provider = domain.get_option('id_provider')
        except SSSDConfig.NoOptionError:
            continue
        if provider == "ipa":
            domain.add_provider('ipa', 'autofs')
            try:
                location = domain.get_option('ipa_automount_location')
                sys.exit('An automount location is already configured')
            except SSSDConfig.NoOptionError:
                domain.set_option('ipa_automount_location', options.location)
                break

    if domain is None:
        sys.exit('SSSD is not configured.')

    sssdconfig.save_domain(domain)
    sssdconfig.write(paths.SSSD_CONF)
    statestore.backup_state('autofs', 'sssd', True)

    sssd = services.service('sssd')
    sssd.restart()
    print("Restarting sssd, waiting for it to become available.")
    wait_for_sssd()

def configure_autofs(fstore, statestore, autodiscover, server, options):
    """
    fstore: the FileStore to back up files in
    options.server: the IPA server to use
    options.location: the Automount location to use
    """
    if not autodiscover:
        ldap_uri = "ldap://%s" % server
    else:
        ldap_uri = "ldap:///%s" % api.env.basedn

    search_base = str(DN(('cn', options.location), api.env.container_automount, api.env.basedn))
    replacevars = {
        'MAP_OBJECT_CLASS': 'automountMap',
        'ENTRY_OBJECT_CLASS': 'automount',
        'MAP_ATTRIBUTE': 'automountMapName',
        'ENTRY_ATTRIBUTE': 'automountKey',
        'VALUE_ATTRIBUTE': 'automountInformation',
        'SEARCH_BASE': search_base,
        'LDAP_URI': ldap_uri,
    }

    ipautil.backup_config_and_replace_variables(fstore,
        paths.SYSCONFIG_AUTOFS, replacevars=replacevars)
    tasks.restore_context(paths.SYSCONFIG_AUTOFS)
    statestore.backup_state('autofs', 'sssd', False)

    print("Configured %s" % paths.SYSCONFIG_AUTOFS)

def configure_autofs_common(fstore, statestore, options):
    autofs = services.knownservices.autofs
    statestore.backup_state('autofs', 'enabled', autofs.is_enabled())
    statestore.backup_state('autofs', 'running', autofs.is_running())
    try:
        autofs.restart()
        print("Started %s" % autofs.service_name)
    except Exception as e:
        root_logger.error("%s failed to restart: %s", autofs.service_name, e)
    try:
        autofs.enable()
    except Exception as e:
        print("Failed to configure automatic startup of the %s daemon" % (autofs.service_name))
        root_logger.error("Failed to enable automatic startup of the %s daemon: %s" % (autofs.service_name, str(e)))

def uninstall(fstore, statestore):
    print("Restoring configuration")
    if fstore.has_file(paths.SYSCONFIG_AUTOFS):
        fstore.restore_file(paths.SYSCONFIG_AUTOFS)
    if fstore.has_file(paths.NSSWITCH_CONF):
        fstore.restore_file(paths.NSSWITCH_CONF)
    if fstore.has_file(paths.AUTOFS_LDAP_AUTH_CONF):
        fstore.restore_file(paths.AUTOFS_LDAP_AUTH_CONF)
    if fstore.has_file(paths.SYSCONFIG_NFS):
        fstore.restore_file(paths.SYSCONFIG_NFS)
    if fstore.has_file(paths.IDMAPD_CONF):
        fstore.restore_file(paths.IDMAPD_CONF)
    if statestore.has_state('autofs'):
        enabled = statestore.restore_state('autofs', 'enabled')
        running = statestore.restore_state('autofs', 'running')
        sssd = statestore.restore_state('autofs', 'sssd')
        autofs = services.knownservices.autofs
        if not enabled:
            autofs.disable()
        if not running:
            autofs.stop()
        if sssd:
            try:
                sssdconfig = SSSDConfig.SSSDConfig()
                sssdconfig.import_config()
                sssdconfig.deactivate_service('autofs')
                domains = sssdconfig.list_active_domains()
                for name in domains:
                    domain = sssdconfig.get_domain(name)
                    try:
                        provider = domain.get_option('id_provider')
                    except SSSDConfig.NoOptionError:
                        continue
                    if provider == "ipa":
                        domain.remove_option('ipa_automount_location')
                        domain.remove_provider('autofs')
                        break
                sssdconfig.save_domain(domain)
                sssdconfig.write(paths.SSSD_CONF)
                sssd = services.service('sssd')
                sssd.restart()
                wait_for_sssd()
            except Exception as e:
                print('Unable to restore SSSD configuration: %s' % str(e))
                root_logger.debug('Unable to restore SSSD configuration: %s' % str(e))
    if statestore.has_state('rpcidmapd'):
        enabled = statestore.restore_state('rpcidmapd', 'enabled')
        running = statestore.restore_state('rpcidmapd', 'running')
        rpcidmapd = services.knownservices.rpcidmapd
        if not enabled:
            rpcidmapd.disable()
        if not running:
            rpcidmapd.stop()
    if statestore.has_state('rpcgssd'):
        enabled = statestore.restore_state('rpcgssd', 'enabled')
        running = statestore.restore_state('rpcgssd', 'running')
        rpcgssd = services.knownservices.rpcgssd
        if not enabled:
            rpcgssd.disable()
        if not running:
            rpcgssd.stop()

    return 0

def configure_nfs(fstore, statestore):
    """
    Configure secure NFS
    """
    replacevars = {
        constants.SECURE_NFS_VAR: 'yes',
    }
    ipautil.backup_config_and_replace_variables(fstore,
        paths.SYSCONFIG_NFS, replacevars=replacevars)
    tasks.restore_context(paths.SYSCONFIG_NFS)

    print("Configured %s" % paths.SYSCONFIG_NFS)

    # Prepare the changes
    # We need to use IPAChangeConf as simple regexp substitution
    # does not cut it here
    conf = ipachangeconf.IPAChangeConf("IPA automount installer")
    conf.case_insensitive_sections = False
    conf.setOptionAssignment(" = ")
    conf.setSectionNameDelimiters(("[", "]"))

    changes = [conf.setOption('Domain', api.env.domain)]
    section_with_changes = [conf.setSection('General', changes)]

    # Backup the file and apply the changes
    fstore.backup_file(paths.IDMAPD_CONF)
    conf.changeConf(paths.IDMAPD_CONF, section_with_changes)

    tasks.restore_context(paths.IDMAPD_CONF)

    print("Configured %s" % paths.IDMAPD_CONF)

    rpcidmapd = services.knownservices.rpcidmapd
    statestore.backup_state('rpcidmapd', 'enabled', rpcidmapd.is_enabled())
    statestore.backup_state('rpcidmapd', 'running', rpcidmapd.is_running())
    try:
        rpcidmapd.restart()
        print("Started %s" % rpcidmapd.service_name)
    except Exception as e:
        root_logger.error("%s failed to restart: %s", rpcidmapd.service_name, e)
    try:
        rpcidmapd.enable()
    except Exception as e:
        print("Failed to configure automatic startup of the %s daemon" % (rpcidmapd.service_name))
        root_logger.error("Failed to enable automatic startup of the %s daemon: %s" % (rpcidmapd.service_name, str(e)))

    rpcgssd = services.knownservices.rpcgssd
    statestore.backup_state('rpcgssd', 'enabled', rpcgssd.is_enabled())
    statestore.backup_state('rpcgssd', 'running', rpcgssd.is_running())
    try:
        rpcgssd.restart()
        print("Started %s" % rpcgssd.service_name)
    except Exception as e:
        root_logger.error("%s failed to restart: %s", rpcgssd.service_name, e)
    try:
        rpcgssd.enable()
    except Exception as e:
        print("Failed to configure automatic startup of the %s daemon" % (rpcgssd.service_name))
        root_logger.error("Failed to enable automatic startup of the %s daemon: %s" % (rpcgssd.service_name, str(e)))

def main():

    fstore = sysrestore.FileStore(paths.IPA_CLIENT_SYSRESTORE)
    statestore = sysrestore.StateFile(paths.IPA_CLIENT_SYSRESTORE)
    if not fstore.has_files() and not os.path.exists(paths.IPA_DEFAULT_CONF):
        sys.exit('IPA client is not configured on this system.\n')

    options, args = parse_options()

    standard_logging_setup(
        paths.IPACLIENT_INSTALL_LOG, verbose=False, debug=options.debug,
        filemode='a', console_format='%(message)s')

    if options.uninstall:
        return uninstall(fstore, statestore)

    cfg = dict(
        context='cli_installer',
        in_server=False,
        debug=options.debug,
        verbose=0,
    )

    api.bootstrap(**cfg)
    api.finalize()

    ca_cert_path = None
    if os.path.exists(paths.IPA_CA_CRT):
        ca_cert_path = paths.IPA_CA_CRT

    if statestore.has_state('autofs'):
        sys.exit('automount is already configured on this system.\n')

    autodiscover = False
    servers = []
    ds = ipadiscovery.IPADiscovery()
    if not options.server:
        print("Searching for IPA server...")
        ret = ds.search(ca_cert_path=ca_cert_path)
        root_logger.debug('Executing DNS discovery')
        if ret == ipadiscovery.NO_LDAP_SERVER:
            root_logger.debug('Autodiscovery did not find LDAP server')
            s = urlsplit(api.env.xmlrpc_uri)
            server = [s.netloc]
            root_logger.debug('Setting server to %s' % s.netloc)
        else:
            autodiscover = True
            if not ds.servers:
                sys.exit('Autodiscovery was successful but didn\'t return a server')
            root_logger.debug('Autodiscovery success, possible servers %s' % ','.join(ds.servers))
            server = ds.servers[0]
    else:
        server = options.server
        root_logger.debug("Verifying that %s is an IPA server" % server)
        ldapret = ds.ipacheckldap(server, api.env.realm, ca_cert_path)
        if ldapret[0] == ipadiscovery.NO_ACCESS_TO_LDAP:
            print("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.")
        elif ldapret[0] == ipadiscovery.NO_TLS_LDAP:
            root_logger.warning("Unencrypted access to LDAP is not supported.")
        elif ldapret[0] != 0:
            sys.exit('Unable to confirm that %s is an IPA server' % server)

    if not autodiscover:
        print("IPA server: %s" % server)
        root_logger.debug('Using fixed server %s' % server)
    else:
        print("IPA server: DNS discovery")
        root_logger.debug('Configuring to use DNS discovery')

    search_base = str(DN(('cn', options.location), api.env.container_automount, api.env.basedn))
    print("Location: %s" % options.location)
    root_logger.debug('Using automount location %s' % options.location)

    ccache_dir = tempfile.mkdtemp()
    ccache_name = os.path.join(ccache_dir, 'ccache')
    try:
        try:
            host_princ = str('host/%s@%s' % (api.env.host, api.env.realm))
            ipautil.kinit_keytab(host_princ, paths.KRB5_KEYTAB, ccache_name)
            os.environ['KRB5CCNAME'] = ccache_name
        except gssapi.exceptions.GSSError as e:
            sys.exit("Failed to obtain host TGT: %s" % e)
        # Now we have a TGT, connect to IPA
        try:
            api.Backend.rpcclient.connect()
        except errors.KerberosError as e:
            sys.exit('Cannot connect to the server due to ' + str(e))
        try:
            # Use the RPC directly so older servers are supported
            result = api.Backend.rpcclient.forward(
                'automountlocation_show',
                ipautil.fsdecode(options.location),
                version=u'2.0',
            )
        except errors.VersionError as e:
            sys.exit('This client is incompatible: ' + str(e))
        except errors.NotFound:
            sys.exit("Automount location '%s' does not exist" % options.location)
        except errors.PublicError as e:
            sys.exit("Cannot connect to the server due to generic error: %s" % str(e))
    finally:
        os.remove(ccache_name)
        os.rmdir(ccache_dir)

    if not options.unattended and not ipautil.user_input("Continue to configure the system with these values?", False):
        sys.exit("Installation aborted")

    try:
        if not options.sssd:
            configure_nsswitch(fstore, options)
        configure_nfs(fstore, statestore)
        if options.sssd:
            configure_autofs_sssd(fstore, statestore, autodiscover, options)
        else:
            configure_xml(fstore)
            configure_autofs(fstore, statestore, autodiscover, server, options)
        configure_autofs_common(fstore, statestore, options)
    except Exception as e:
        root_logger.debug('Raised exception %s' % e)
        print("Installation failed. Rolling back changes.")
        uninstall(fstore, statestore)
        return 1

    return 0

try:
    if not os.geteuid()==0:
        sys.exit("\nMust be run as root\n")

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