ovn-sb: Remove the "Gateway" table from the ovn-sb schema.

In a gateway like the VTEP L2 gateway, physical vlans belonging to
the same logical network form a "logical switch".  Each logical switch
has a dedicated tunnel key and will keep records of all MACs learned
from the owned vlans.  So user can just send packet to a "logical
switch" and the gateway will figure out the output port and vlan tag
automatically.

Therefore, it is really not necessary to keep record of the vlan map
for each gateway physical port in the OVN_Southbound database using
"gateway_ports" and to map each vlan to a unique ovn logical port.
Instead, we should simply map each logical switch to a ovn logical
port.

Thusly, this commit removes the "Gateway" table from the OVN_Southbound
database.  In the "Chassis" table, the "gateway_ports" column is replaced
by "vtep_logical_switches" column which stores all vtep logical switch
names.  The use of this column will be documented in later commit.

Signed-off-by: Alex Wang <[email protected]>
Acked-by: Russell Bryant <[email protected]>

ovn/ovn-sb.ovsschema

@@ -7,12 +7,9 @@
                 "encaps": {"type": {"key": {"type": "uuid",
                                             "refTable": "Encap"},
                                     "min": 1, "max": "unlimited"}},
-                "gateway_ports": {"type": {"key": "string",
-                                           "value": {"type": "uuid",
-                                                     "refTable": "Gateway",
-                                                     "refType": "strong"},
-                                           "min": 0,
-                                           "max": "unlimited"}}},
+                "vtep_logical_switches" : {"type": {"key": "string",
+                                                    "min": 0,
+                                                    "max": "unlimited"}}},
             "isRoot": true,
             "indexes": [["name"]]},
         "Encap": {
@@ -25,13 +22,6 @@
                                      "min": 0,
                                      "max": "unlimited"}},
                 "ip": {"type": "string"}}},
-        "Gateway": {
-            "columns": {"vlan_map": {"type": {"key": {"type": "integer",
-                                                      "minInteger": 0,
-                                                      "maxInteger": 4095},
-                                              "value": {"type": "string"},
-                                              "min": 0,
-                                              "max": "unlimited"}}}},
         "Logical_Flow": {
             "columns": {
                 "logical_datapath": {"type": {"key": {"type": "uuid",

ovn/ovn-sb.xml

@@ -35,8 +35,7 @@
   </p>
 
   <p>
-    The <ref table="Chassis"/> and <ref table="Gateway"/> tables comprise the
-    PN tables.
+    The <ref table="Chassis"/> table comprises the PN tables.
   </p>
 
   <h3>Logical Network (LN) data</h3>
@@ -163,20 +162,19 @@
       </column>
     </group>
 
-    <group title="Gateway Configuration">
-      <p>
-        A <dfn>gateway</dfn> is a chassis that forwards traffic between a
-        logical network and a physical VLAN.  Gateways are typically dedicated
-        nodes that do not host VMs.
+     <group title="Gateway Configuration">
+       <p>
+        A <dfn>gateway</dfn> is a chassis that forwards traffic between the
+        OVN-managed part of a logical network and a physical VLAN, extending a
+        tunnel-based logical network into a physical network.  Gateways are
+        typically dedicated nodes that do not host VMs.
       </p>
 
-      <column name="gateway_ports">
-        Maps from the name of a port attached to the OVN integration bridge
-        (typically a physical port or an Open vSwitch patch port) to a <ref
-        table="Gateway"/> record that describes the details of the gatewaying
-        function.
+      <column name="vtep_logical_switches">
+        Stores all vtep logical switch names connected by this gateway
+        chassis.
       </column>
-    </group>
+     </group>
   </table>
 
   <table name="Encap" title="Encapsulation Types">
@@ -206,23 +204,6 @@
     </column>
   </table>
 
-  <table name="Gateway" title="Physical Network Gateway Ports">
-    <p>
-      The <ref column="gateway_ports" table="Chassis"/> column in the <ref
-      table="Chassis"/> table refers to rows in this table to connect a chassis
-      port to a gateway function.  Each row in this table describes the logical
-      networks to which a gateway port is attached.  Each chassis, via
-      <code>ovn-controller</code>(8), adds and updates its own rows, if any
-      (since most chassis are not gateways), and keeps a copy of the remaining
-      rows to determine how to reach other chassis.
-    </p>
-
-    <column name="vlan_map">
-      Maps from a VLAN ID to a logical port name.  Thus, each named logical
-      port corresponds to one VLAN on the gateway port.
-    </column>
-  </table>
-
   <table name="Logical_Flow" title="Logical Network Flows">
     <p>
       Each row in this table represents one logical flow.  The cloud management
@@ -642,11 +623,10 @@
         Most of the symbols below have integer type.  Only <code>inport</code>
         and <code>outport</code> have string type.  <code>inport</code> names a
         logical port.  Thus, its value is a <ref column="logical_port"/> name
-        from the <ref table="Port_Binding"/> or <ref table="Gateway"/> tables.
-        <code>outport</code> may name a logical port, as <code>inport</code>,
-        or a logical multicast group defined in the <ref
-        table="Multicast_Group"/> table.  For both symbols, only names within
-        the flow's logical datapath may be used.
+        from the <ref table="Port_Binding"/> table.  <code>outport</code> may
+        name a logical port, as <code>inport</code>, or a logical multicast
+        group defined in the <ref table="Multicast_Group"/> table.  For both
+        symbols, only names within the flow's logical datapath may be used.
       </p>
 
       <ul>