Merge pull request #1130 from dcantah/backport-hcnfeaturechecks

[release/0.8] Cherry-pick hcn feature check improvements

hcn/hcn.go

@@ -127,7 +127,10 @@ func platformDoesNotSupportError(featureName string) error {
 
 // V2ApiSupported returns an error if the HCN version does not support the V2 Apis.
 func V2ApiSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.Api.V2 {
 		return nil
 	}
@@ -143,7 +146,10 @@ func V2SchemaVersion() SchemaVersion {
 
 // RemoteSubnetSupported returns an error if the HCN version does not support Remote Subnet policies.
 func RemoteSubnetSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.RemoteSubnet {
 		return nil
 	}
@@ -152,7 +158,10 @@ func RemoteSubnetSupported() error {
 
 // HostRouteSupported returns an error if the HCN version does not support Host Route policies.
 func HostRouteSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.HostRoute {
 		return nil
 	}
@@ -161,7 +170,10 @@ func HostRouteSupported() error {
 
 // DSRSupported returns an error if the HCN version does not support Direct Server Return.
 func DSRSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.DSR {
 		return nil
 	}
@@ -170,7 +182,10 @@ func DSRSupported() error {
 
 // Slash32EndpointPrefixesSupported returns an error if the HCN version does not support configuring endpoints with /32 prefixes.
 func Slash32EndpointPrefixesSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.Slash32EndpointPrefixes {
 		return nil
 	}
@@ -179,7 +194,10 @@ func Slash32EndpointPrefixesSupported() error {
 
 // AclSupportForProtocol252Supported returns an error if the HCN version does not support HNS ACL Policies to support protocol 252 for VXLAN.
 func AclSupportForProtocol252Supported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.AclSupportForProtocol252 {
 		return nil
 	}
@@ -188,7 +206,10 @@ func AclSupportForProtocol252Supported() error {
 
 // SessionAffinitySupported returns an error if the HCN version does not support Session Affinity.
 func SessionAffinitySupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.SessionAffinity {
 		return nil
 	}
@@ -197,7 +218,10 @@ func SessionAffinitySupported() error {
 
 // IPv6DualStackSupported returns an error if the HCN version does not support IPv6DualStack.
 func IPv6DualStackSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.IPv6DualStack {
 		return nil
 	}
@@ -206,7 +230,10 @@ func IPv6DualStackSupported() error {
 
 //L4proxySupported returns an error if the HCN verison does not support L4Proxy
 func L4proxyPolicySupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.L4Proxy {
 		return nil
 	}
@@ -215,7 +242,10 @@ func L4proxyPolicySupported() error {
 
 // L4WfpProxySupported returns an error if the HCN verison does not support L4WfpProxy
 func L4WfpProxyPolicySupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.L4WfpProxy {
 		return nil
 	}
@@ -224,7 +254,10 @@ func L4WfpProxyPolicySupported() error {
 
 // SetPolicySupported returns an error if the HCN version does not support SetPolicy.
 func SetPolicySupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.SetPolicy {
 		return nil
 	}
@@ -233,7 +266,10 @@ func SetPolicySupported() error {
 
 // VxlanPortSupported returns an error if the HCN version does not support configuring the VXLAN TCP port.
 func VxlanPortSupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.VxlanPort {
 		return nil
 	}
@@ -242,7 +278,10 @@ func VxlanPortSupported() error {
 
 // TierAclPolicySupported returns an error if the HCN version does not support configuring the TierAcl.
 func TierAclPolicySupported() error {
-	supported := GetSupportedFeatures()
+	supported, err := GetCachedSupportedFeatures()
+	if err != nil {
+		return err
+	}
 	if supported.TierAcl {
 		return nil
 	}

hcn/hcnsupport.go

@@ -1,9 +1,21 @@
 package hcn
 
 import (
+	"fmt"
+	"sync"
+
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
+var (
+	// featuresOnce handles assigning the supported features and printing the supported info to stdout only once to avoid unnecessary work
+	// multiple times.
+	featuresOnce      sync.Once
+	featuresErr       error
+	supportedFeatures SupportedFeatures
+)
+
 // SupportedFeatures are the features provided by the Service.
 type SupportedFeatures struct {
 	Acl                      AclFeatures `json:"ACL"`
@@ -36,17 +48,41 @@ type ApiSupport struct {
 	V2 bool `json:"V2"`
 }
 
+// GetCachedSupportedFeatures returns the features supported by the Service and an error if the query failed. If this has been called
+// before it will return the supported features and error received from the first call. This can be used to optimize if many calls to the
+// various hcn.IsXSupported methods need to be made.
+func GetCachedSupportedFeatures() (SupportedFeatures, error) {
+	// Only query the HCN version and features supported once, instead of everytime this is invoked. The logs are useful to
+	// debug incidents where there's confusion on if a feature is supported on the host machine. The sync.Once helps to avoid redundant
+	// spam of these anytime a check needs to be made for if an HCN feature is supported. This is a common occurrence in kube-proxy
+	// for example.
+	featuresOnce.Do(func() {
+		supportedFeatures, featuresErr = getSupportedFeatures()
+	})
+
+	return supportedFeatures, featuresErr
+}
+
 // GetSupportedFeatures returns the features supported by the Service.
+//
+// Deprecated: Use GetCachedSupportedFeatures instead.
 func GetSupportedFeatures() SupportedFeatures {
-	var features SupportedFeatures
-
-	globals, err := GetGlobals()
+	features, err := GetCachedSupportedFeatures()
 	if err != nil {
 		// Expected on pre-1803 builds, all features will be false/unsupported
-		logrus.Debugf("Unable to obtain globals: %s", err)
+		logrus.WithError(err).Errorf("unable to obtain supported features")
 		return features
 	}
+	return features
+}
 
+func getSupportedFeatures() (SupportedFeatures, error) {
+	var features SupportedFeatures
+	globals, err := GetGlobals()
+	if err != nil {
+		// It's expected if this fails once, it should always fail. It should fail on pre 1803 builds for example.
+		return SupportedFeatures{}, errors.Wrap(err, "failed to query HCN version number: this is expected on pre 1803 builds.")
+	}
 	features.Acl = AclFeatures{
 		AclAddressLists:       isFeatureSupported(globals.Version, HNSVersion1803),
 		AclNoHostRulePriority: isFeatureSupported(globals.Version, HNSVersion1803),
@@ -72,7 +108,12 @@ func GetSupportedFeatures() SupportedFeatures {
 	features.L4WfpProxy = isFeatureSupported(globals.Version, L4WfpProxyPolicyVersion)
 	features.TierAcl = isFeatureSupported(globals.Version, TierAclPolicyVersion)
 
-	return features
+	logrus.WithFields(logrus.Fields{
+		"version":           fmt.Sprintf("%+v", globals.Version),
+		"supportedFeatures": fmt.Sprintf("%+v", features),
+	}).Info("HCN feature check")
+
+	return features, nil
 }
 
 func isFeatureSupported(currentVersion Version, versionsSupported VersionRanges) bool {
@@ -87,19 +128,15 @@ func isFeatureSupported(currentVersion Version, versionsSupported VersionRanges)
 
 func isFeatureInRange(currentVersion Version, versionRange VersionRange) bool {
 	if currentVersion.Major < versionRange.MinVersion.Major {
-		logrus.Infof("currentVersion.Major < versionRange.MinVersion.Major: %v, %v", currentVersion.Major, versionRange.MinVersion.Major)
 		return false
 	}
 	if currentVersion.Major > versionRange.MaxVersion.Major {
-		logrus.Infof("currentVersion.Major > versionRange.MaxVersion.Major: %v, %v", currentVersion.Major, versionRange.MaxVersion.Major)
 		return false
 	}
 	if currentVersion.Major == versionRange.MinVersion.Major && currentVersion.Minor < versionRange.MinVersion.Minor {
-		logrus.Infof("currentVersion.Minor < versionRange.MinVersion.Major: %v, %v", currentVersion.Minor, versionRange.MinVersion.Minor)
 		return false
 	}
 	if currentVersion.Major == versionRange.MaxVersion.Major && currentVersion.Minor > versionRange.MaxVersion.Minor {
-		logrus.Infof("currentVersion.Minor > versionRange.MaxVersion.Major: %v, %v", currentVersion.Minor, versionRange.MaxVersion.Minor)
 		return false
 	}
 	return true