Simplify k8s replicated set deployment (#8666)

Continuation from #8629 which basically broke
zone deployments on k8s statefulset environment
due to incorrect assumptions which made it work
on replicated set.

Fix this properly such that this container works
for both replicated set and stateful set deployment

cmd/endpoint.go

@@ -230,40 +230,23 @@ func (endpoints Endpoints) GetString(i int) string {
 	return endpoints[i].String()
 }
 
-func (endpoints Endpoints) atleastOneEndpointLocal() bool {
-	for _, endpoint := range endpoints {
-		if endpoint.IsLocal {
-			return true
-		}
-	}
-	return false
-}
-
-func (endpoints Endpoints) doAllHostsResolveToLocalhost() bool {
-	var endpointHosts = map[string]set.StringSet{}
+func (endpoints Endpoints) doAnyHostsResolveToLocalhost() bool {
 	for _, endpoint := range endpoints {
 		hostIPs, err := getHostIP(endpoint.Hostname())
 		if err != nil {
 			continue
 		}
-		endpointHosts[endpoint.Hostname()] = hostIPs
-	}
-	sameHosts := make(map[string]int)
-	for hostName, endpointIPs := range endpointHosts {
-		for _, endpointIP := range endpointIPs.ToSlice() {
-			if net.ParseIP(endpointIP).IsLoopback() {
-				sameHosts[hostName]++
+		var loopback int
+		for _, hostIP := range hostIPs.ToSlice() {
+			if net.ParseIP(hostIP).IsLoopback() {
+				loopback++
 			}
 		}
+		if loopback == len(hostIPs) {
+			return true
+		}
 	}
-	ok := true
-	for _, localCount := range sameHosts {
-		ok = ok && localCount > 0
-	}
-	if len(sameHosts) == 0 {
-		return false
-	}
-	return ok
+	return false
 }
 
 // UpdateIsLocal - resolves the host and discovers the local host.
@@ -301,8 +284,8 @@ func (endpoints Endpoints) UpdateIsLocal() error {
 					endpoints[i].Hostname(),
 				)
 
-				if orchestrated && endpoints.doAllHostsResolveToLocalhost() {
-					err := errors.New("hosts resolve to same IP, DNS not updated on k8s")
+				if orchestrated && endpoints.doAnyHostsResolveToLocalhost() {
+					err := errors.New("hosts resolve 127.*, DNS not updated on k8s")
 					// time elapsed
 					timeElapsed := time.Since(startTime)
 					// log error only if more than 1s elapsed
@@ -346,10 +329,6 @@ func (endpoints Endpoints) UpdateIsLocal() error {
 				} else {
 					resolvedList[i] = true
 					endpoints[i].IsLocal = isLocal
-					if orchestrated && !endpoints.atleastOneEndpointLocal() {
-						resolvedList[i] = false
-						continue
-					}
 					epsResolved++
 					if !foundLocal {
 						foundLocal = isLocal