Integrate gstate with resource-allocator interface

- Also did some cleanup around leftover (dead)code in netd.go which for
  handling gstate events inside netplugin.
- One big change around resource specification is that the checks have
  become strict. Example, a vxlan-range is not allowed to be configured
  if the vnid range exceeds 4k vlans (needed for vxlan functionality).
  On similar lines the default for an empty vlan range (specified in tenant
  config) now results in not creating a vlan resoure at all (unlike reserving
  1-4095 vlan tags earlier.)
  This change allows failing earlier than later. It also requires a more
  explicit configuration (for vlan and vxlan ranges) than assuming
  pre-configured defaults.

Author: mapuri

core/core.go

@@ -126,8 +126,8 @@ type Resource interface {
 
 type ResourceAllocator interface {
 	// A resource allocator provides mechanism to manage (define/undefine,
-	// allocate/deallocate) resources, in logically centralized manner, in
-	// a distributed system
+	// allocate/deallocate) resources. Example, it may provide management in
+	// logically centralized manner in a distributed system
 	Init() error
 	Deinit()
 	DefineResource(id, desc string, rsrcCfg interface{}) error

examples/late_bindings/multiple_vxlan_nets.json

@@ -13,7 +13,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "10001-14000",
         "Networks"  : [ {
             "Name"                  : "orange",
             "Endpoints" : [ {

examples/multiple_eps_in_container.json

@@ -13,7 +13,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "10001-14000",
         "Networks"  : [
         {
             "Name"                  : "orange",

examples/two_host_vxlan.json

@@ -13,7 +13,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "10001-14000",
         "Networks"  : [
         {
             "Name"                  : "orange",

examples/two_hosts_multiple_tenants.json

@@ -13,7 +13,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "10001-12000",
         "Networks"  : [ {
             "Name"                  : "orange",
             "Endpoints" : [
@@ -32,7 +32,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "15001-17000",
         "Networks"  : [ {
             "Name"                  : "purple",
             "Endpoints" : [

examples/two_hosts_multiple_tenants_mix_vlan_vxlan.json

@@ -33,7 +33,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "10001-14000",
         "Networks"  : [{
             "Name"                  : "purple",
             "Endpoints" : [{

examples/two_hosts_multiple_vxlan_nets.json

@@ -13,7 +13,7 @@
         "DefaultNetType"            : "vxlan",
         "SubnetPool"                : "11.1.0.0/16",
         "AllocSubnetLen"            : 24,
-        "Vxlans"                    : "10001-20000",
+        "Vxlans"                    : "10001-14000",
         "Networks"  : [ {
             "Name"                  : "orange",
             "Endpoints" : [