[ovs-dev] [PATCH] rhel: Add support for "systemctl reload openvswitch"

[Ben Pfaff]

On Fri, Nov 03, 2017 at 01:55:00PM -0200, Flavio Leitner wrote:
> On Tue, 31 Oct 2017 12:11:32 +0100
> Timothy Redaelli <tredaelli at redhat.com> wrote:
> 
> > The reload procedure will trigger a script that saves the flows and tlv
> > maps (using ovs-save) then it restarts ovsdb-server, it stops ovs-vswitchd,
> > it sets other_config:flow-restore-wait=true (to wait till flow restore is
> > finished), it starts ovs-vswitchd, it restore the backupped flows/tlv
> > maps and it removes other_config:flow-restore-wait=true (logic mostly ripped
> > from ovs-ctl).
> > 
> > It uses systemctl with --job-mode=ignore-dependencies to restart ovsdb-server
> > and stop and start ovs-vswitchd in order to avoid systemd to restart the other
> > components due to dependencies (as explained in rhel/README.RHEL.rst).
> > 
> > Signed-off-by: Timothy Redaelli <tredaelli at redhat.com>
> > ---
> >  rhel/automake.mk                                 |  1 +
> >  rhel/openvswitch-fedora.spec.in                  |  5 ++++
> >  rhel/usr_lib_systemd_system_openvswitch.service  |  2 +-
> >  rhel/usr_lib_systemd_system_ovsdb-server.service |  1 -
> >  rhel/usr_share_openvswitch_scripts_ovs-reload    | 36 ++++++++++++++++++++++++
> >  5 files changed, 43 insertions(+), 2 deletions(-)
> >  create mode 100755 rhel/usr_share_openvswitch_scripts_ovs-reload
> > 
> > diff --git a/rhel/automake.mk b/rhel/automake.mk
> > index 9336f0912..0955dceed 100644
> > --- a/rhel/automake.mk
> > +++ b/rhel/automake.mk
> > @@ -24,6 +24,7 @@ EXTRA_DIST += \
> >  	rhel/openvswitch.spec.in \
> >  	rhel/openvswitch-fedora.spec \
> >  	rhel/openvswitch-fedora.spec.in \
> > +	rhel/usr_share_openvswitch_scripts_ovs-reload \
> >  	rhel/usr_share_openvswitch_scripts_sysconfig.template \
> >  	rhel/usr_share_openvswitch_scripts_systemd_sysconfig.template \
> >  	rhel/usr_lib_udev_rules.d_91-vfio.rules \
> > diff --git a/rhel/openvswitch-fedora.spec.in b/rhel/openvswitch-fedora.spec.in
> > index fb7d918c6..87bec39c9 100644
> > --- a/rhel/openvswitch-fedora.spec.in
> > +++ b/rhel/openvswitch-fedora.spec.in
> > @@ -314,6 +314,10 @@ install -d -m 0755 $RPM_BUILD_ROOT%{_prefix}/lib/ocf/resource.d/ovn
> >  ln -s %{_datadir}/openvswitch/scripts/ovndb-servers.ocf \
> >        $RPM_BUILD_ROOT%{_prefix}/lib/ocf/resource.d/ovn/ovndb-servers
> >  
> > +install -p -D -m 0755 \
> > +        rhel/usr_share_openvswitch_scripts_ovs-reload \
> > +        $RPM_BUILD_ROOT%{_datadir}/openvswitch/scripts/ovs-reload
> > +
> >  # remove unpackaged files
> >  rm -f $RPM_BUILD_ROOT%{_bindir}/ovs-parse-backtrace \
> >          $RPM_BUILD_ROOT%{_sbindir}/ovs-vlan-bug-workaround \
> > @@ -539,6 +543,7 @@ fi
> >  %{_datadir}/openvswitch/scripts/ovs-save
> >  %{_datadir}/openvswitch/scripts/ovs-vtep
> >  %{_datadir}/openvswitch/scripts/ovs-ctl
> > +%{_datadir}/openvswitch/scripts/ovs-reload
> >  %config %{_datadir}/openvswitch/vswitch.ovsschema
> >  %config %{_datadir}/openvswitch/vtep.ovsschema
> >  %{_bindir}/ovs-appctl
> > diff --git a/rhel/usr_lib_systemd_system_openvswitch.service b/rhel/usr_lib_systemd_system_openvswitch.service
> > index faca44b54..2cf29f0e9 100644
> > --- a/rhel/usr_lib_systemd_system_openvswitch.service
> > +++ b/rhel/usr_lib_systemd_system_openvswitch.service
> > @@ -9,7 +9,7 @@ Requires=ovs-vswitchd.service
> >  [Service]
> >  Type=oneshot
> >  ExecStart=/bin/true
> > -ExecReload=/bin/true
> > +ExecReload=/usr/share/openvswitch/scripts/ovs-reload
> >  ExecStop=/bin/true
> >  RemainAfterExit=yes
> >  
> > diff --git a/rhel/usr_lib_systemd_system_ovsdb-server.service b/rhel/usr_lib_systemd_system_ovsdb-server.service
> > index 5baac822d..234d39355 100644
> > --- a/rhel/usr_lib_systemd_system_ovsdb-server.service
> > +++ b/rhel/usr_lib_systemd_system_ovsdb-server.service
> > @@ -3,7 +3,6 @@ Description=Open vSwitch Database Unit
> >  After=syslog.target network-pre.target
> >  Before=network.target network.service
> >  Wants=ovs-delete-transient-ports.service
> > -ReloadPropagatedFrom=openvswitch.service
> >  PartOf=openvswitch.service
> >  
> >  [Service]
> > diff --git a/rhel/usr_share_openvswitch_scripts_ovs-reload b/rhel/usr_share_openvswitch_scripts_ovs-reload
> > new file mode 100755
> > index 000000000..3ac1a46c6
> > --- /dev/null
> > +++ b/rhel/usr_share_openvswitch_scripts_ovs-reload
> > @@ -0,0 +1,36 @@
> > +#! /bin/sh
> > +
> > +# Copyright (c) 2017 Red Hat, Inc.
> > +#
> > +# Licensed under the Apache License, Version 2.0 (the "License");
> > +# you may not use this file except in compliance with the License.
> > +# You may obtain a copy of the License at:
> > +#
> > +#     http://www.apache.org/licenses/LICENSE-2.0
> > +#
> > +# Unless required by applicable law or agreed to in writing, software
> > +# distributed under the License is distributed on an "AS IS" BASIS,
> > +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
> > +# See the License for the specific language governing permissions and
> > +# limitations under the License.
> > +
> > +# Save flows
> > +bridges=$(ovs-vsctl -- --real list-br)
> > +flows=$(/usr/share/openvswitch/scripts/ovs-save save-flows $bridges)
> > +
> > +# Restart the database first, since a large database may take a
> > +# while to load, and we want to minimize forwarding disruption.
> > +systemctl --job-mode=ignore-dependencies restart ovsdb-server
> > +
> > +# Stop ovs-vswitchd.
> > +systemctl --job-mode=ignore-dependencies stop ovs-vswitchd
> > +
> > +# Start vswitchd by asking it to wait till flow restore is finished.
> > +ovs-vsctl --no-wait set open_vswitch . other_config:flow-restore-wait=true
> > +systemctl --job-mode=ignore-dependencies start ovs-vswitchd
> > +
> > +# Restore saved flows and inform vswitchd that we are done.
> > +eval "$flows"
> > +ovs-vsctl --if-exists remove open_vswitch . other_config flow-restore-wait=true
> > +
> > +exit 0
> 
> 
> This looks good to me, my only comment is that the script is in rhel/
> and uses systemd so maybe we should reflect that in the script's name?
> Because OVS itself might provide an ovs-reload too and then we will
> have issues.
> 
> What do you think?

Is this script reasonably generic, as opposed to RHEL-specific?  If so
then we could move it into utilities or make it a command under ovs-ctl.