Added distribution type option to loadbalancer

Author: elweb9858

hcn/hcn.go

@@ -179,6 +179,15 @@ func AclSupportForProtocol252Supported() error {
 	return platformDoesNotSupportError("HNS ACL Policies to support protocol 252 for VXLAN")
 }
 
+// SessionAffinitySupported returns an error if the HCN version does not support Session Affinity.
+func SessionAffinitySupported() error {
+	supported := GetSupportedFeatures()
+	if supported.SessionAffinity {
+		return nil
+	}
+	return platformDoesNotSupportError("Session Affinity")
+}
+
 // RequestType are the different operations performed to settings.
 // Used to update the settings of Endpoint/Namespace objects.
 type RequestType string

hcn/hcnglobals.go

@@ -49,6 +49,8 @@ var (
 		VersionRange{MinVersion: Version{Major: 9, Minor: 3}, MaxVersion: Version{Major: 9, Minor: math.MaxInt32}},
 		VersionRange{MinVersion: Version{Major: 10, Minor: 4}, MaxVersion: Version{Major: math.MaxInt32, Minor: math.MaxInt32}},
 	}
+	// HNS 11.10 allows for session affinity for loadbalancing
+	SessionAffinityVersion = VersionRanges{VersionRange{MinVersion: Version{Major: 11, Minor: 10}, MaxVersion: Version{Major: math.MaxInt32, Minor: math.MaxInt32}}}
 )
 
 // GetGlobals returns the global properties of the HCN Service.

hcn/hcnloadbalancer.go

@@ -10,10 +10,11 @@ import (
 
 // LoadBalancerPortMapping is associated with HostComputeLoadBalancer
 type LoadBalancerPortMapping struct {
-	Protocol     uint32                       `json:",omitempty"` // EX: TCP = 6, UDP = 17
-	InternalPort uint16                       `json:",omitempty"`
-	ExternalPort uint16                       `json:",omitempty"`
-	Flags        LoadBalancerPortMappingFlags `json:",omitempty"`
+	Protocol         uint32                       `json:",omitempty"` // EX: TCP = 6, UDP = 17
+	InternalPort     uint16                       `json:",omitempty"`
+	ExternalPort     uint16                       `json:",omitempty"`
+	DistributionType LoadBalancerDistribution     `json:",omitempty"` // EX: Distribute per connection = 0, distribute traffic of the same protocol per client IP = 1, distribute per client IP = 2
+	Flags            LoadBalancerPortMappingFlags `json:",omitempty"`
 }
 
 // HostComputeLoadBalancer represents software load balancer.
@@ -53,6 +54,22 @@ var (
 	LoadBalancerPortMappingFlagsPreserveDIP LoadBalancerPortMappingFlags = 8
 )
 
+// LoadBalancerDistribution specifies how the loadbalancer distributes traffic.
+type LoadBalancerDistribution uint32
+
+var (
+	// LoadBalancerDistributionNone is the default and loadbalances each connection to the same pod.
+	LoadBalancerDistributionNone LoadBalancerDistribution
+	// LoadBalancerDistributionSourceIPProtocol loadbalances all traffic of the same protocol from a client IP to the same pod.
+	LoadBalancerDistributionSourceIPProtocol LoadBalancerDistribution = 1
+	// LoadBalancerDistributionSourceIP loadbalances all traffic from a client IP to the same pod.
+	LoadBalancerDistributionSourceIP LoadBalancerDistribution = 2
+)
+
+func (distributionType LoadBalancerDistribution) String() string {
+	return [...]string{"None", "SourceIPProtocol", "SourceIP"}[distributionType]
+}
+
 func getLoadBalancer(loadBalancerGuid guid.GUID, query string) (*HostComputeLoadBalancer, error) {
 	// Open loadBalancer.
 	var (
@@ -312,17 +329,18 @@ func (loadBalancer *HostComputeLoadBalancer) RemoveEndpoint(endpoint *HostComput
 }
 
 // AddLoadBalancer for the specified endpoints
-func AddLoadBalancer(endpoints []HostComputeEndpoint, flags LoadBalancerFlags, portMappingFlags LoadBalancerPortMappingFlags, sourceVIP string, frontendVIPs []string, protocol uint16, internalPort uint16, externalPort uint16) (*HostComputeLoadBalancer, error) {
-	logrus.Debugf("hcn::HostComputeLoadBalancer::AddLoadBalancer endpointId=%v, LoadBalancerFlags=%v, LoadBalancerPortMappingFlags=%v, sourceVIP=%s, frontendVIPs=%v, protocol=%v, internalPort=%v, externalPort=%v", endpoints, flags, portMappingFlags, sourceVIP, frontendVIPs, protocol, internalPort, externalPort)
+func AddLoadBalancer(endpoints []HostComputeEndpoint, flags LoadBalancerFlags, portMappingFlags LoadBalancerPortMappingFlags, sourceVIP string, frontendVIPs []string, protocol uint16, internalPort uint16, externalPort uint16, additionalParams ...string) (*HostComputeLoadBalancer, error) {
+	logrus.Debugf("hcn::HostComputeLoadBalancer::AddLoadBalancer endpointId=%v, LoadBalancerFlags=%v, LoadBalancerPortMappingFlags=%v, sourceVIP=%s, frontendVIPs=%v, protocol=%v, internalPort=%v, externalPort=%v, additionalParams=%v", endpoints, flags, portMappingFlags, sourceVIP, frontendVIPs, protocol, internalPort, externalPort, additionalParams)
 
 	loadBalancer := &HostComputeLoadBalancer{
 		SourceVIP: sourceVIP,
 		PortMappings: []LoadBalancerPortMapping{
 			{
-				Protocol:     uint32(protocol),
-				InternalPort: internalPort,
-				ExternalPort: externalPort,
-				Flags:        portMappingFlags,
+				Protocol:         uint32(protocol),
+				InternalPort:     internalPort,
+				ExternalPort:     externalPort,
+				DistributionType: LoadBalancerDistributionNone,
+				Flags:            portMappingFlags,
 			},
 		},
 		FrontendVIPs: frontendVIPs,
@@ -333,6 +351,15 @@ func AddLoadBalancer(endpoints []HostComputeEndpoint, flags LoadBalancerFlags, p
 		Flags: flags,
 	}
 
+	if additionalParams != nil {
+		switch additionalParams[0] {
+		case "SourceIPProtocol":
+			loadBalancer.PortMappings[0].DistributionType = LoadBalancerDistributionSourceIPProtocol
+		case "SourceIP":
+			loadBalancer.PortMappings[0].DistributionType = LoadBalancerDistributionSourceIP
+		}
+	}
+
 	for _, endpoint := range endpoints {
 		loadBalancer.HostComputeEndpoints = append(loadBalancer.HostComputeEndpoints, endpoint.Id)
 	}

hcn/hcnsupport.go

@@ -13,6 +13,7 @@ type SupportedFeatures struct {
 	DSR                      bool        `json:"DSR"`
 	Slash32EndpointPrefixes  bool        `json:"Slash32EndpointPrefixes"`
 	AclSupportForProtocol252 bool        `json:"AclSupportForProtocol252"`
+	SessionAffinity          bool        `json:"SessionAffinity"`
 }
 
 // AclFeatures are the supported ACL possibilities.
@@ -57,6 +58,7 @@ func GetSupportedFeatures() SupportedFeatures {
 	features.DSR = isFeatureSupported(globals.Version, DSRVersion)
 	features.Slash32EndpointPrefixes = isFeatureSupported(globals.Version, Slash32EndpointPrefixesVersion)
 	features.AclSupportForProtocol252 = isFeatureSupported(globals.Version, AclSupportForProtocol252Version)
+	features.SessionAffinity = isFeatureSupported(globals.Version, SessionAffinityVersion)
 
 	return features
 }

hcn/hcnsupport_test.go

@@ -83,6 +83,17 @@ func TestAclSupportForProtocol252Support(t *testing.T) {
 	}
 }
 
+func TestSessionAffinitySupport(t *testing.T) {
+	supportedFeatures := GetSupportedFeatures()
+	err := SessionAffinitySupported()
+	if supportedFeatures.SessionAffinity && err != nil {
+		t.Fatal(err)
+	}
+	if !supportedFeatures.SessionAffinity && err == nil {
+		t.Fatal(err)
+	}
+}
+
 func TestIsFeatureSupported(t *testing.T) {
 	// HNSVersion1803 testing (single range tests)
 	if isFeatureSupported(Version{Major: 0, Minor: 0}, HNSVersion1803) {