Remove firewalld on Fedora 20 by default

firewalld interacts badly with the libvirt on f20, causing slow-downs
so great that it can timeout the gate.

Developers who want to leave it enabled should set FORCE_FIREWALLD=True

Change-Id: I5252a12223a35f7fb7a4ac3c58aa4a3cd1bc4799

lib/nova_plugins/functions-libvirt

@@ -37,7 +37,7 @@ function install_libvirt {
     # and HP images used in the gate; rackspace has firewalld but hp
     # cloud doesn't.  RHEL6 doesn't have firewalld either.  So we
     # don't care if it fails.
-    if is_fedora; then
+    if is_fedora && is_package_installed firewalld; then
         sudo service firewalld restart || true
     fi
 }

tools/fixup_stuff.sh

@@ -103,6 +103,21 @@ if is_fedora; then
     if selinuxenabled; then
         sudo setenforce 0
     fi
+
+    FORCE_FIREWALLD=$(trueorfalse False $FORCE_FIREWALLD)
+    if [[ ${DISTRO} =~ (f19|f20) && $FORCE_FIREWALLD == "False" ]]; then
+        # On Fedora 19 and 20 firewalld interacts badly with libvirt and
+        # slows things down significantly.  However, for those cases
+        # where that combination is desired, allow this fix to be skipped.
+
+        # There was also an additional issue with firewalld hanging
+        # after install of libvirt with polkit.  See
+        # https://bugzilla.redhat.com/show_bug.cgi?id=1099031
+        if is_package_installed firewalld; then
+            uninstall_package firewalld
+        fi
+    fi
+
 fi
 
 # RHEL6