# # Copyright (C) 2016 FreeIPA Contributors see COPYING for license # """ This module contains the set of classes which abstract various bits and pieces of information present in the LDAP tree about functionalities such as DNS server, Active Directory trust controller etc. These properties come in two distinct groups: server roles this group represents a genral functionality provided by one or more IPA servers, such as DNS server, certificate authority and such. In this case there is a many-to-many mapping between the roles and the masters which provide them. server attributes these represent a functionality associated with the whole topology, such as CA renewal master or DNSSec key master. See the corresponding design page (http://www.freeipa.org/page/V4/Server_Roles) for more info. Both of these groups use `LDAPBasedProperty` class as a base. Server Roles ============ Server role objects are usually consuming information from the master's service container (cn=FQDN,cn=masters,cn=ipa,cn=etc,$SUFFIX) are represented by `ServiceBasedRole`class. To create an instance of such role, you only need to specify role name and individual services comprising the role (more systemd services may be enabled to provide some function): >>> example_role = ServiceBasedRole( ... "Example Role", ... component_services = ['SERVICE1', 'SERVICE2']) >>> example_role.name 'Example Role' The role object can then be queried for the status of the role in the whole topology or on a single master by using its `status` method. This method returns a list of dictionaries akin to LDAP entries comprised from server name, role name and role status (enabled if role is enabled, configured if the service entries are present but not marked as enabled by 'enabledService' config string, absent if the service entries are not present). Note that 'AD trust agent' role is based on membership of the master in the 'adtrust agents' sysaccount group and is thus an instance of different class (`ADTrustBasedRole`). This role also does not have 'configured' status, since the master is either member of the group ('enabled') or not ('absent') Server Attributes ================= Server attributes are implemented as instances of `ServerAttribute` class. The attribute is defined by some flag set on 'ipaConfigString' attribute of some service entry. To create your own server attribute, see the following example: >>> example_attribute = ServerAttribute("Example Attribute", example_role, ... "SERVICE1", "roleMaster") >>> example_attribute.name 'Example Attribute' The FQDN of master with the attribute set can be requested using `get()` method. The attribute master can be changed by the `set()` method which accepts FQDN of a new master hosting the attribute. The available role/attribute instances are stored in `role_instances`/`attribute_instances` tuples. """ import abc from collections import namedtuple, defaultdict from ldap import SCOPE_ONELEVEL import six from ipalib import _, errors from ipapython.dn import DN from ipaserver.masters import ENABLED_SERVICE if six.PY3: unicode = str ENABLED = u'enabled' CONFIGURED = u'configured' ABSENT = u'absent' @six.add_metaclass(abc.ABCMeta) class LDAPBasedProperty: """ base class for all master properties defined by LDAP content :param attr_name: attribute name :param name: user-friendly name of the property :param attrs_list: list of attributes to retrieve during search, defaults to all """ def __init__(self, attr_name, name): self.attr_name = attr_name self.name = name @six.add_metaclass(abc.ABCMeta) class BaseServerRole(LDAPBasedProperty): """ Server role hierarchy apex. All other server role definition should either inherit from it or at least provide the 'status' method for querying role status property """ def create_role_status_dict(self, server, status): """ the output of `status()` method should be a list of dictionaries having the following keys: * role_servrole: name of role * server_server: server FQDN * status: role status on server this methods returns such a dict given server and role status """ return { u'role_servrole': self.name, u'server_server': server, u'status': status} @abc.abstractmethod def create_search_params(self, ldap, api_instance, server=None): """ create search base and filter :param ldap: ldap connection :param api_instance: API instance :param server: server FQDN. if given, the method should generate filter and search base matching only the status on this server :returns: tuple of search base (a DN) and search filter """ @abc.abstractmethod def get_result_from_entries(self, entries): """ Get role status from returned LDAP entries :param entries: LDAPEntry objects returned by `search()` :returns: list of dicts generated by `create_role_status_dict()` method """ def _fill_in_absent_masters(self, ldap2, api_instance, result): """ get all masters on which the role is absent :param ldap2: LDAP connection :param api_instance: API instance :param result: output of `get_result_from_entries` method :returns: list of masters on which the role is absent """ search_base = DN(api_instance.env.container_masters, api_instance.env.basedn) search_filter = '(objectclass=ipaConfigObject)' attrs_list = ['cn'] all_masters = ldap2.get_entries( search_base, filter=search_filter, scope=SCOPE_ONELEVEL, attrs_list=attrs_list) all_master_cns = set(m['cn'][0] for m in all_masters) enabled_configured_masters = set(r[u'server_server'] for r in result) absent_masters = all_master_cns.difference(enabled_configured_masters) return [self.create_role_status_dict(m, ABSENT) for m in absent_masters] def status(self, api_instance, server=None, attrs_list=("*",)): """ probe and return status of the role either on single server or on the whole topology :param api_instance: API instance :param server: server FQDN. If given, only the status of the role on this master will be returned :returns: * 'enabled' if the role is enabled on the master * 'configured' if it is not enabled but has been configured by installer * 'absent' otherwise """ ldap2 = api_instance.Backend.ldap2 search_base, search_filter = self.create_search_params( ldap2, api_instance, server=server) try: entries = ldap2.get_entries( search_base, filter=search_filter, attrs_list=attrs_list) except errors.EmptyResult: entries = [] if not entries and server is not None: return [self.create_role_status_dict(server, ABSENT)] result = self.get_result_from_entries(entries) if server is None: result.extend( self._fill_in_absent_masters(ldap2, api_instance, result)) return sorted(result, key=lambda x: x[u'server_server']) class ServerAttribute(LDAPBasedProperty): """ Class from which server attributes should be instantiated :param associated_role_name: name of a role which must be enabled on the provider :param associated_service_name: name of LDAP service on which the attribute is set. Does not need to belong to the service entries of associate role :param ipa_config_string_value: value of `ipaConfigString` attribute associated with the presence of server attribute """ def __init__(self, attr_name, name, associated_role_name, associated_service_name, ipa_config_string_value): super(ServerAttribute, self).__init__(attr_name, name) self.associated_role_name = associated_role_name self.associated_service_name = associated_service_name self.ipa_config_string_value = ipa_config_string_value @property def associated_role(self): for inst in role_instances: if self.associated_role_name == inst.attr_name: return inst raise NotImplementedError( "{}: no valid associated role found".format(self.attr_name)) def create_search_filter(self, ldap): """ Create search filter which matches LDAP data corresponding to the attribute """ svc_filter = ldap.make_filter_from_attr( 'cn', self.associated_service_name) configstring_filter = ldap.make_filter_from_attr( 'ipaConfigString', self.ipa_config_string_value) return ldap.combine_filters( [svc_filter, configstring_filter], rules=ldap.MATCH_ALL) def get(self, api_instance): """ get the master which has the attribute set :param api_instance: API instance :returns: master FQDN """ ldap2 = api_instance.Backend.ldap2 search_base = DN(api_instance.env.container_masters, api_instance.env.basedn) search_filter = self.create_search_filter(ldap2) try: entries = ldap2.get_entries(search_base, filter=search_filter) except errors.EmptyResult: return [] master_cns = {e.dn[1]['cn'] for e in entries} associated_role_providers = set( self._get_assoc_role_providers(api_instance)) if not master_cns.issubset(associated_role_providers): raise errors.ValidationError( name=self.name, error=_("all masters must have %(role)s role enabled" % {'role': self.associated_role.name}) ) return sorted(master_cns) def _get_master_dns(self, api_instance, servers): return [ DN(('cn', server), api_instance.env.container_masters, api_instance.env.basedn) for server in servers] def _get_masters_service_entries(self, ldap, master_dns): service_dns = [ DN(('cn', self.associated_service_name), master_dn) for master_dn in master_dns] return [ldap.get_entry(service_dn) for service_dn in service_dns] def _add_attribute_to_svc_entry(self, ldap, service_entry): """ add the server attribute to the entry of associated service :param ldap: LDAP connection object :param service_entry: associated service entry """ ipa_config_string = service_entry.get('ipaConfigString', []) ipa_config_string.append(self.ipa_config_string_value) service_entry['ipaConfigString'] = ipa_config_string ldap.update_entry(service_entry) def _remove_attribute_from_svc_entry(self, ldap, service_entry): """ remove the server attribute to the entry of associated service single ipaConfigString attribute is case-insensitive, we must handle arbitrary case of target value :param ldap: LDAP connection object :param service_entry: associated service entry """ ipa_config_string = service_entry.get('ipaConfigString', []) for value in ipa_config_string: if value.lower() == self.ipa_config_string_value.lower(): service_entry['ipaConfigString'].remove(value) ldap.update_entry(service_entry) def _get_assoc_role_providers(self, api_instance): """ get list of all servers on which the associated role is enabled """ return [ r[u'server_server'] for r in self.associated_role.status( api_instance) if r[u'status'] == ENABLED] def _remove(self, api_instance, masters): """ remove attribute from one or more masters :param api_instance: API instance :param master: list or iterable containing master FQDNs """ ldap = api_instance.Backend.ldap2 master_dns = self._get_master_dns(api_instance, masters) service_entries = self._get_masters_service_entries(ldap, master_dns) for service_entry in service_entries: self._remove_attribute_from_svc_entry(ldap, service_entry) def _add(self, api_instance, masters): """ add attribute to the master :param api_instance: API instance :param master: iterable containing master FQDNs :raises: * errors.ValidationError if the associated role is not enabled on the master """ ldap = api_instance.Backend.ldap2 master_dns = self._get_master_dns(api_instance, masters) service_entries = self._get_masters_service_entries(ldap, master_dns) for service_entry in service_entries: self._add_attribute_to_svc_entry(ldap, service_entry) def _check_receiving_masters_having_associated_role(self, api_instance, masters): assoc_role_providers = set( self._get_assoc_role_providers(api_instance)) masters_set = set(masters) masters_without_role = masters_set - assoc_role_providers if masters_without_role: raise errors.ValidationError( name=', '.join(sorted(masters_without_role)), error=_("must have %(role)s role enabled" % {'role': self.associated_role.name}) ) def set(self, api_instance, masters): """ set the attribute on masters :param api_instance: API instance :param masters: an interable with FQDNs of the new masters the attribute is automatically unset from previous masters if present :raises: errors.EmptyModlist if the new masters is the same as the original ones """ old_masters = self.get(api_instance) if sorted(old_masters) == sorted(masters): raise errors.EmptyModlist self._check_receiving_masters_having_associated_role( api_instance, masters) if old_masters: self._remove(api_instance, old_masters) self._add(api_instance, masters) class SingleValuedServerAttribute(ServerAttribute): """ Base class for server attributes that are forced to be single valued this means that `get` method will return a one-element list, and `set` method will accept only one-element list """ def set(self, api_instance, masters): if len(masters) > 1: raise errors.ValidationError( name=self.attr_name, error=_("must be enabled only on a single master")) super(SingleValuedServerAttribute, self).set(api_instance, masters) def get(self, api_instance): masters = super(SingleValuedServerAttribute, self).get(api_instance) num_masters = len(masters) if num_masters > 1: raise errors.SingleMatchExpected(found=num_masters) return masters _Service = namedtuple('Service', ['name', 'enabled']) class ServiceBasedRole(BaseServerRole): """ class for all role instances whose status is defined by presence of one or more entries in LDAP and/or their attributes """ def __init__(self, attr_name, name, component_services): super(ServiceBasedRole, self).__init__(attr_name, name) self.component_services = component_services def _validate_component_services(self, services): svc_set = {s.name for s in services} if svc_set != set(self.component_services): raise ValueError( "{}: Mismatch between component services and search result " "(expected: {}, got: {})".format( self.__class__.__name__, ', '.join(sorted(self.component_services)), ', '.join(sorted(s.name for s in services)))) def _get_service(self, entry): entry_cn = entry['cn'][0] enabled = self._is_service_enabled(entry) return _Service(name=entry_cn, enabled=enabled) def _is_service_enabled(self, entry): """ determine whether the service is enabled based on the presence of enabledService attribute in ipaConfigString attribute. Since the attribute is case-insensitive, we must first lowercase its values and do the comparison afterwards. :param entry: LDAPEntry of the service :returns: True if the service entry is enabled, False otherwise """ ipaconfigstring_values = set(entry.get('ipaConfigString', [])) return ENABLED_SERVICE in ipaconfigstring_values def _get_services_by_masters(self, entries): """ given list of entries, return a dictionary keyed by master FQDNs which contains list of service entries belonging to the master """ services_by_master = defaultdict(list) for e in entries: service = self._get_service(e) master_cn = e.dn[1]['cn'] services_by_master[master_cn].append(service) return services_by_master def get_result_from_entries(self, entries): result = [] services_by_master = self._get_services_by_masters(entries) for master, services in services_by_master.items(): try: self._validate_component_services(services) except ValueError: continue status = ( ENABLED if all(s.enabled for s in services) else CONFIGURED) result.append(self.create_role_status_dict(master, status)) return result def create_search_params(self, ldap, api_instance, server=None): search_base = DN(api_instance.env.container_masters, api_instance.env.basedn) search_filter = ldap.make_filter_from_attr( 'cn', self.component_services, rules=ldap.MATCH_ANY, exact=True ) if server is not None: search_base = DN(('cn', server), search_base) return search_base, search_filter def status(self, api_instance, server=None): return super(ServiceBasedRole, self).status( api_instance, server=server, attrs_list=('ipaConfigString', 'cn')) class ADtrustBasedRole(BaseServerRole): """ Class which should instantiate roles besed on membership in 'adtrust agent' sysaccount group. """ def get_result_from_entries(self, entries): result = [] for e in entries: result.append( self.create_role_status_dict(e['fqdn'][0], ENABLED) ) return result def create_search_params(self, ldap, api_instance, server=None): search_base = DN( api_instance.env.container_host, api_instance.env.basedn) search_filter = ldap.make_filter_from_attr( "memberof", DN(('cn', 'adtrust agents'), ('cn', 'sysaccounts'), ('cn', 'etc'), api_instance.env.basedn) ) if server is not None: server_filter = ldap.make_filter_from_attr( 'fqdn', server, exact=True ) search_filter = ldap.combine_filters( [search_filter, server_filter], rules=ldap.MATCH_ALL ) return search_base, search_filter role_instances = ( ADtrustBasedRole(u"ad_trust_agent_server", u"AD trust agent"), ServiceBasedRole( u"ad_trust_controller_server", u"AD trust controller", component_services=['ADTRUST'] ), ServiceBasedRole( u"ca_server_server", u"CA server", component_services=['CA'] ), ServiceBasedRole( u"dns_server_server", u"DNS server", component_services=['DNS', 'DNSKeySync'] ), ServiceBasedRole( u"ipa_master_server", u"IPA master", component_services=['HTTP', 'KDC', 'KPASSWD'] ), ServiceBasedRole( u"kra_server_server", u"KRA server", component_services=['KRA'] ) ) attribute_instances = ( SingleValuedServerAttribute( u"ca_renewal_master_server", u"CA renewal master", u"ca_server_server", u"CA", u"caRenewalMaster", ), SingleValuedServerAttribute( u"dnssec_key_master_server", u"DNSSec key master", u"dns_server_server", u"DNSSEC", u"dnssecKeyMaster", ), ServerAttribute( u"pkinit_server_server", u"PKINIT enabled server", u"ipa_master_server", u"KDC", u"pkinitEnabled" ) )