ipa-adtrust-install: run remote configuration for new agents

When ipa-adtrust-install is run, the tool detects masters that are
not enabled as trust agents and propose to configure them. With the
current code, the Schema Compat plugin is not enabled on these new
trust agents and a manual restart of LDAP server + SSSD is required.

With this commit, ipa-adtrust-install now calls remote code on the new
agents through JSON RPC api, in order to configure the missing parts.
On the remote agent, the command is using DBus and oddjob to launch
a new command,
/usr/libexec/ipa/oddjob/org.freeipa.server.trust-enable-agent [--enable-compat]
This command configures the Schema Compat plugin if --enable-compat is
provided, then restarts LDAP server and SSSD.

If the remote agent is an older version and does not support remote
enablement, or if the remote server is not responding, the tool
ipa-adtrust-install prints a WARNING explaining the steps that need
to be manually executed in order to complete the installation, and
exits successfully (keeping the current behavior).

Fixes: https://pagure.io/freeipa/issue/7600
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Sergey Orlov <sorlov@redhat.com>

ipaserver/plugins/trust.py

@@ -26,6 +26,7 @@ from ipalib.messages import (
     add_message,
     BrokenTrust)
 from ipalib.plugable import Registry
+from ipalib.request import context
 from .baseldap import (
     pkey_to_value,
     entry_to_dict,
@@ -42,6 +43,7 @@ from ipapython.ipautil import realm_to_suffix
 from ipalib import api, Str, StrEnum, Password, Bool, _, ngettext, Int, Flag
 from ipalib import Command
 from ipalib import errors
+from ipalib import messages
 from ipalib import output
 from ldap import SCOPE_SUBTREE
 from time import sleep
@@ -52,6 +54,7 @@ from ipaserver.dcerpc_common import (TRUST_ONEWAY,
                                      trust_type_string,
                                      trust_direction_string,
                                      trust_status_string)
+from ipaserver.plugins.privilege import principal_has_privilege
 
 if six.PY3:
     unicode = str
@@ -1828,6 +1831,71 @@ class trust_fetch_domains(LDAPRetrieve):
         return result
 
 
+@register()
+class trust_enable_agent(Command):
+    __doc__ = _("Configure this server as a trust agent.")
+
+    NO_CLI = True
+
+    has_output = output.standard_value
+    takes_args = (
+        Str(
+            'remote_cn',
+            cli_name='remote_name',
+            label=_('Remote server name'),
+            doc=_('Remote IPA server hostname'),
+        ),
+    )
+
+    takes_options = (
+        Flag('enable_compat',
+             doc=_('Enable support for trusted domains for old clients'),
+             default=False),
+    )
+
+    def execute(self, *keys, **options):
+        # the server must be the local host
+        # This check is needed because the forward method may failover
+        # to a master different from the one specified
+        if keys[0] != api.env.host:
+            raise errors.ValidationError(
+                name='cn', error=_("must be \"%s\"") % api.env.host)
+
+        # the user must have the Replication Administrators privilege
+        privilege = u'Replication Administrators'
+        if not principal_has_privilege(self.api, context.principal, privilege):
+            raise errors.ACIError(
+                info=_("not allowed to remotely add agent"))
+
+        # Trust must be configured
+
+        if options[u'enable_compat']:
+            method_arguments = "--enable-compat"
+        else:
+            method_arguments = ""
+
+        dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
+
+        bus = dbus.SystemBus()
+        obj = bus.get_object('org.freeipa.server', '/',
+                             follow_name_owner_changes=True)
+        server = dbus.Interface(obj, 'org.freeipa.server')
+
+        ret, stdout, stderr = server.trust_enable_agent(method_arguments)
+
+        result = dict(
+            result=(ret == 0),
+            value=keys[0],
+        )
+
+        for line in stdout.splitlines() + stderr.splitlines():
+            messages.add_message(options['version'],
+                                 result,
+                                 messages.ExternalCommandOutput(line=line))
+
+        return result
+
+
 @register()
 class trustdomain_enable(LDAPQuery):
     __doc__ = _('Allow use of IPA resources by the domain of the trust')