plugin/kubernetes: Watch EndpointSlices (#4209)

* initial commit

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* convert endpointslices to object.endpoints

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* add opt hard coded for now

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* check that server supports endpointslice

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* fix import grouping

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* dont use endpoint slice in 1.17 or 1.18

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* bump kind/k8s in circle ci to latest

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* drop k8s to latest supported by kind

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* use endpointslice name as endoint Name; index by Service name

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* use index key comparison in nsAddrs()

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* add Index to object.Endpoint fixtures; fix direct endpoint name compares

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* add slice dup check and test

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* todo

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* add ep-slice skew dup test for reverse

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* nsaddrs: de-dup ep-slice skew dups; add test

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* remove todo

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* address various feedback

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* consolidate endpoint/slice informer code

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* fix endpoint informer consolidation; use clearer func name

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* log info; use major/minor fields

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* fix nsAddr and unit test

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* add latency tracking for endpointslices

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* endpointslice latency unit test & fix

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* code shuffling

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* rename endpointslices in tests

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* remove de-dup from nsAddrs and test

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

* remove de-dup from findServices / test

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

2 files changed, 58 insertions, 2 deletions

diff --git a/plugin/kubernetes/object/endpoint.go b/plugin/kubernetes/object/endpoint.go
index d4c495861..304aaa861 100644
--- a/plugin/kubernetes/object/endpoint.go
+++ b/plugin/kubernetes/object/endpoint.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	api "k8s.io/api/core/v1"
+	discovery "k8s.io/api/discovery/v1beta1"
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
@@ -56,6 +57,17 @@ func ToEndpoints(skipCleanup bool) ToFunc {
 	}
 }
 
+// EndpointSliceToEndpoints returns a function that converts an *discovery.EndpointSlice to a *Endpoints.
+func EndpointSliceToEndpoints(skipCleanup bool) ToFunc {
+	return func(obj interface{}) (interface{}, error) {
+		eps, ok := obj.(*discovery.EndpointSlice)
+		if !ok {
+			return nil, fmt.Errorf("unexpected object %v", obj)
+		}
+		return endpointSliceToEndpoints(skipCleanup, eps), nil
+	}
+}
+
 // toEndpoints converts an *api.Endpoints to a *Endpoints.
 func toEndpoints(skipCleanup bool, end *api.Endpoints) *Endpoints {
 	e := &Endpoints{
@@ -108,6 +120,49 @@ func toEndpoints(skipCleanup bool, end *api.Endpoints) *Endpoints {
 	return e
 }
 
+// endpointSliceToEndpoints converts a *discovery.EndpointSlice to a *Endpoints.
+func endpointSliceToEndpoints(skipCleanup bool, ends *discovery.EndpointSlice) *Endpoints {
+	e := &Endpoints{
+		Version:   ends.GetResourceVersion(),
+		Name:      ends.GetName(),
+		Namespace: ends.GetNamespace(),
+		Index:     EndpointsKey(ends.Labels[discovery.LabelServiceName], ends.GetNamespace()),
+		Subsets:   make([]EndpointSubset, 1),
+	}
+
+	if len(ends.Ports) == 0 {
+		// Add sentinel if there are no ports.
+		e.Subsets[0].Ports = []EndpointPort{{Port: -1}}
+	} else {
+		e.Subsets[0].Ports = make([]EndpointPort, len(ends.Ports))
+		for k, p := range ends.Ports {
+			ep := EndpointPort{Port: *p.Port, Name: *p.Name, Protocol: string(*p.Protocol)}
+			e.Subsets[0].Ports[k] = ep
+		}
+	}
+
+	for _, end := range ends.Endpoints {
+		for _, a := range end.Addresses {
+			ea := EndpointAddress{IP: a}
+			if end.Hostname != nil {
+				ea.Hostname = *end.Hostname
+			}
+			if end.TargetRef != nil {
+				ea.TargetRefName = end.TargetRef.Name
+			}
+			// EndpointSlice does not contain NodeName, leave blank
+			e.Subsets[0].Addresses = append(e.Subsets[0].Addresses, ea)
+			e.IndexIP = append(e.IndexIP, a)
+		}
+	}
+
+	if !skipCleanup {
+		*ends = discovery.EndpointSlice{}
+	}
+
+	return e
+}
+
 // CopyWithoutSubsets copies e, without the subsets.
 func (e *Endpoints) CopyWithoutSubsets() *Endpoints {
 	e1 := &Endpoints{
diff --git a/plugin/kubernetes/object/informer.go b/plugin/kubernetes/object/informer.go
index f37af4796..afd134e56 100644
--- a/plugin/kubernetes/object/informer.go
+++ b/plugin/kubernetes/object/informer.go
@@ -21,10 +21,11 @@ func NewIndexerInformer(lw cache.ListerWatcher, objType runtime.Object, h cache.
 	return clientState, cache.New(cfg)
 }
 
-type recordLatencyFunc func(meta.Object)
+// RecordLatencyFunc is a function for recording api object delta latency
+type RecordLatencyFunc func(meta.Object)
 
 // DefaultProcessor is based on the Process function from cache.NewIndexerInformer except it does a conversion.
-func DefaultProcessor(convert ToFunc, recordLatency recordLatencyFunc) ProcessorBuilder {
+func DefaultProcessor(convert ToFunc, recordLatency RecordLatencyFunc) ProcessorBuilder {
 	return func(clientState cache.Indexer, h cache.ResourceEventHandler) cache.ProcessFunc {
 		return func(obj interface{}) error {
 			for _, d := range obj.(cache.Deltas) {