Give better errors if PolicyKit auth fails

Coupled with a recent libvirt patch, try and give more info about
a couple common policykit failure scenarios, like launching virt-manager
over SSH or VNC.

Do this by checking to see if we have a 'session' with ConsoleKit: the
above culprits don't give the user a local session, which causes
PolicyKit to deny.

src/virtManager/connection.py

@@ -20,11 +20,11 @@
 
 import logging
 import os
-import traceback
 import re
+import socket
 import threading
 import time
-import socket
+import traceback
 
 import dbus
 import libvirt
@@ -48,6 +48,34 @@ def _is_virtinst_test_uri(uri):
     except:
         return False
 
+def _do_we_have_session():
+    pid = os.getpid()
+
+    try:
+        bus = dbus.SystemBus()
+    except:
+        logging.exception("Error getting system bus handle")
+        return False
+
+    # Check ConsoleKit
+    try:
+        manager = dbus.Interface(bus.get_object(
+                                 "org.freedesktop.ConsoleKit",
+                                 "/org/freedesktop/ConsoleKit/Manager"),
+                                 "org.freedesktop.ConsoleKit.Manager")
+    except:
+        logging.exception("Couldn't connect to ConsoleKit")
+        return False
+
+    try:
+        ret = manager.GetSessionForUnixProcess(pid)
+        logging.debug("Found ConsoleKit session=%s" % ret)
+    except:
+        logging.exception("Failed to lookup pid session")
+        return False
+
+    return True
+
 class vmmConnection(vmmGObject):
 
     STATE_DISCONNECTED = 0
@@ -1151,6 +1179,7 @@ class vmmConnection(vmmGObject):
             libexc = None
             exc = None
             tb = None
+            warnconsole = False
             try:
                 self.vmm = self._try_open()
             except libvirt.libvirtError, libexc:
@@ -1173,6 +1202,15 @@ class vmmConnection(vmmGObject):
                 logging.debug("User cancelled auth, not raising any error.")
                 break
 
+            if (libexc and
+                libexc.get_error_code() == libvirt.VIR_ERR_AUTH_FAILED and
+                "not authorized" in libexc.get_error_message().lower()):
+                logging.debug("Looks like we might have failed policykit "
+                              "auth. Checking to see if we have a valid "
+                              "console session")
+                if not self.is_remote() and not _do_we_have_session():
+                    warnconsole = True
+
             if (libexc and
                 libexc.get_error_code() == libvirt.VIR_ERR_AUTH_FAILED and
                 "GSSAPI Error" in libexc.get_error_message() and
@@ -1180,7 +1218,7 @@ class vmmConnection(vmmGObject):
                 if self._acquire_tgt():
                     continue
 
-            self.connectError = "%s\n\n%s" % (exc, tb)
+            self.connectError = (str(exc), tb, warnconsole)
             break
 
         # We want to kill off this thread asap, so schedule an
@@ -1208,7 +1246,7 @@ class vmmConnection(vmmGObject):
 
         if self.state == self.STATE_DISCONNECTED:
             if self.connectError:
-                self.idle_emit("connect-error", self.connectError)
+                self.idle_emit("connect-error", *self.connectError)
             self.connectError = None
 
 
@@ -1706,4 +1744,4 @@ vmmGObject.signal_new(vmmConnection, "mediadev-removed", [str])
 
 vmmGObject.signal_new(vmmConnection, "resources-sampled", [])
 vmmGObject.signal_new(vmmConnection, "state-changed", [])
-vmmGObject.signal_new(vmmConnection, "connect-error", [str])
+vmmGObject.signal_new(vmmConnection, "connect-error", [str, str, bool])

src/virtManager/manager.py

@@ -644,27 +644,42 @@ class vmmManager(vmmGObjectUI):
             conn.open()
             return True
 
-    def _connect_error(self, conn, details):
-        if conn.get_driver() == "xen" and not conn.is_remote():
-            self.err.show_err(
-            _("Unable to open a connection to the Xen hypervisor/daemon.\n\n" +
-              "Verify that:\n" +
-              " - A Xen host kernel was booted\n" +
-              " - The Xen service has been started\n"),
-              details=details,
-              title=_("Virtual Machine Manager Connection Failure"))
+    def _connect_error(self, conn, shortmsg, tb, warnconsole):
+        shortmsg = shortmsg.strip(" \n")
+        tb = tb.strip(" \n")
+        msg = _("Unable to connect to libvirt:\n\n%s\n\n") % shortmsg
+
+        if conn.is_xen() and not conn.is_remote():
+            msg += _("Verify that:\n"
+                     " - A Xen host kernel was booted\n"
+                     " - The Xen service has been started\n")
+            msg = msg.strip("\n")
+            details = "%s\n\n%s" % (msg, tb)
+
         else:
-            hint = ''
-            if re.search(r"nc: .* -- 'U'", details):
-                hint = _("\n - The remote netcat understands the '-U' option")
-            self.err.show_err(
-            _("Unable to open a connection to the libvirt "
-              "management daemon.\n\n" +
-              "Libvirt URI is: %s\n\n" % conn.get_uri() +
-              "Verify that:\n" +
-              " - The 'libvirtd' daemon has been started") + hint,
-              details=details,
-              title=_("Virtual Machine Manager Connection Failure"))
+            hints = []
+            if conn.is_remote() and re.search(r"nc: .* -- 'U'", details):
+                hints.append(
+                    _("\n - The remote netcat understands the '-U' option"))
+
+            if warnconsole:
+                msg += _("Could not detect a local session: if you are \n"
+                         "running virt-manager over ssh -X or VNC, you \n"
+                         "may not be able to connect to libvirt as a \n"
+                         "regular user. Try running as root.\n\n")
+            else:
+                msg += _("Verify that:\n" +
+                         " - The 'libvirtd' daemon has been started")
+                for hint in hints:
+                    msg += hint
+
+            msg = msg.strip("\n")
+            details = (("%s\n\n" % msg) +
+                       (_("Libvirt URI is: %s\n\n") % conn.get_uri()) +
+                       tb)
+
+        self.err.show_err(msg, details,
+                    title=_("Virtual Machine Manager Connection Failure"))
 
 
     ####################################