[ovs-dev] [PATCH] ovn: support requested-chassis option for logical switch ports

[Lance Richardson]

This patch adds support for a "requested-chassis" option for logical
switch ports. If set, the only chassis that will claim this port is the
chassis identfied by this option; if already bound by another chassis,
it will be released.

The primary benefit of this enhancement is allowing a CMS to prevent
"thrashing" in the southbound database during live migration by keeping
the original chassis from attempting to re-bind a port that is in the
process of migrating.

This would also allow (with some additional work) RBAC to be applied
to the Port_Binding table for additional security.

Signed-off-by: Lance Richardson <lrichard at redhat.com>
---
 ovn/controller/binding.c | 15 +++++++++++-
 ovn/ovn-nb.xml           |  5 ++++
 ovn/ovn-sb.xml           |  5 ++++
 tests/ovn.at             | 59 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/ovn/controller/binding.c b/ovn/controller/binding.c
index 32309e9e3..6a56e26ca 100644
--- a/ovn/controller/binding.c
+++ b/ovn/controller/binding.c
@@ -440,7 +440,12 @@ consider_local_datapath(struct controller_ctx *ctx,
     }
 
     if (ctx->ovnsb_idl_txn) {
-        if (our_chassis) {
+        const char *vif_chassis = smap_get(&binding_rec->options,
+                                           "requested-chassis");
+        bool can_bind = !vif_chassis || !vif_chassis[0] ||
+                        !strcmp(vif_chassis, chassis_rec->name);
+
+        if (can_bind && our_chassis) {
             if (binding_rec->chassis != chassis_rec) {
                 if (binding_rec->chassis) {
                     VLOG_INFO("Changing chassis for lport %s from %s to %s.",
@@ -461,6 +466,14 @@ consider_local_datapath(struct controller_ctx *ctx,
             VLOG_INFO("Releasing lport %s from this chassis.",
                       binding_rec->logical_port);
             sbrec_port_binding_set_chassis(binding_rec, NULL);
+        } else if (our_chassis) {
+            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
+            VLOG_INFO_RL(&rl,
+                         "Not claiming lport %s, chassis %s "
+                         "requested-chassis %s",
+                         binding_rec->logical_port,
+                         chassis_rec->name,
+                         vif_chassis);
         }
     }
 }
diff --git a/ovn/ovn-nb.xml b/ovn/ovn-nb.xml
index 31303a846..7db860f57 100644
--- a/ovn/ovn-nb.xml
+++ b/ovn/ovn-nb.xml
@@ -435,6 +435,11 @@
           (empty string)
         </p>
 
+        <column name="options" key="requested-chassis">
+          If set, identifies a specific chassis (by name) that is allowed to
+          bind this port.
+        </column>
+
         <column name="options" key="qos_max_rate">
           If set, indicates the maximum rate for data sent from this interface,
           in bit/s. The traffic will be shaped according to this limit.
diff --git a/ovn/ovn-sb.xml b/ovn/ovn-sb.xml
index 08d784ac6..583f8ae39 100644
--- a/ovn/ovn-sb.xml
+++ b/ovn/ovn-sb.xml
@@ -2159,6 +2159,11 @@ tcp.flags = RST;
         (empty string)
       </p>
 
+      <column name="options" key="requested-chassis">
+        If set, identifies a specific chassis (by name) that is allowed to
+        bind this port.
+      </column>
+
       <column name="options" key="qos_max_rate">
         If set, indicates the maximum rate for data sent from this interface,
         in bit/s. The traffic will be shaped according to this limit.
diff --git a/tests/ovn.at b/tests/ovn.at
index 7d816785e..dcd0cf1a1 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -8281,3 +8281,62 @@ AT_CHECK([grep "Releasing lport" gw1/ovn-controller.log], [1], [])
 OVN_CLEANUP([gw1],[gw2],[hv1])
 
 AT_CLEANUP
+
+AT_SETUP([ovn -- options:requested-chassis for logical port])
+ovn_start
+
+net_add n1
+
+ovn-nbctl ls-add ls0
+ovn-nbctl lsp-add ls0 lsp0
+
+# create two hypervisors, each with one vif port
+sim_add hv1
+as hv1
+ovs-vsctl add-br br-phys
+ovn_attach n1 br-phys 192.168.0.11
+ovs-vsctl -- add-port br-int hv1-vif0
+
+sim_add hv2
+as hv2
+ovs-vsctl add-br br-phys
+ovn_attach n1 br-phys 192.168.0.12
+ovs-vsctl -- add-port br-int hv2-vif0
+
+# Allow only chassis hv1 to bind logical port lsp0.
+ovn-nbctl lsp-set-options lsp0 requested-chassis=hv1
+
+# Allow some time for ovn-northd and ovn-controller to catch up.
+ovn-nbctl --wait=hv --timeout=3 sync
+
+# Retrieve hv1 and hv2 chassis UUIDs from southbound database
+hv1_uuid=$(ovn-sbctl --bare --columns _uuid find chassis name=hv1)
+hv2_uuid=$(ovn-sbctl --bare --columns _uuid find chassis name=hv2)
+
+# (1) Chassis hv2 should not bind lsp0 when requested-chassis is hv1.
+echo "verifying that hv2 does not bind lsp0 when hv2 physical/logical mapping is added"
+as hv2
+ovs-vsctl set interface hv2-vif0 external-ids:iface-id=lsp0
+
+OVS_WAIT_UNTIL([test 1 = $(grep -c "Not claiming lport lsp0" hv2/ovn-controller.log)])
+AT_CHECK([test x$(ovn-sbctl --bare --columns chassis find port_binding logical_port=lsp0) = x], [0], [])
+
+# (2) Chassis hv1 should bind lsp0 when physical to logical mapping exists on hv1.
+echo "verifying that hv1 binds lsp0 when hv1 physical/logical mapping is added"
+as hv1
+ovs-vsctl set interface hv1-vif0 external-ids:iface-id=lsp0
+
+OVS_WAIT_UNTIL([test 1 = $(grep -c "Claiming lport lsp0" hv1/ovn-controller.log)])
+AT_CHECK([test $(ovn-sbctl --bare --columns chassis find port_binding logical_port=lsp0) = "$hv1_uuid"], [0], [])
+
+# (3) Chassis hv1 should release lsp0 binding and chassis hv2 should bind lsp0 when
+# the requested chassis for lsp0 is changed from hv1 to hv2.
+echo "verifying that lsp0 binding moves when requested-chassis is changed"
+
+ovn-nbctl lsp-set-options lsp0 requested-chassis=hv2
+OVS_WAIT_UNTIL([test 1 = $(grep -c "Releasing lport lsp0 from this chassis" hv1/ovn-controller.log)])
+OVS_WAIT_UNTIL([test $(ovn-sbctl --bare --columns chassis find port_binding logical_port=lsp0) = "$hv2_uuid"])
+
+OVN_CLEANUP([hv1],[hv2])
+
+AT_CLEANUP
-- 
2.13.4