**Fixed** a bug when a Sidecar is resource is defined with multiple egress listeners with different ports 
  of a Kubernetes service, does not merge the ports correctly. This leads to creating only one Cluster with 

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: db-tls
spec:
  host: mydbserver.prod.svc.cluster.local
  trafficPolicy:
    portLevelSettings:
      - port:
          number: 443
        tls:
          mode: SIMPLE

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: db-tls
spec:
  host: mydbserver.prod.svc.cluster.local
  trafficPolicy:
    portLevelSettings:
      - port:
          number: 443
        tls:
          mode: SIMPLE
          credentialName: db-credential
  workloadSelector:
      matchLabels:

          - --xds-grpc-server={{ $p.Port }}
{{- else if eq .Protocol "GRPC" }}
          - --grpc={{ $p.Port }}
{{- else if eq .Protocol "TCP" }}
          - --tcp={{ $p.Port }}
{{- else }}
          - --port={{ $p.Port }}
{{- end }}
{{- if $p.TLS }}
          - --tls={{ $p.Port }}
{{- end }}
{{- if $p.ServerFirst }}
          - --server-first={{ $p.Port }}
{{- end }}
{{- if $p.InstanceIP }}

		klog.Warningf("port is not in the range when release it. port: %v", port)
		return nil
	}

	err := r.alloc.Release(offset)
	if err == nil {
		// update metrics
		r.metrics.setAllocated(r.Used())
		r.metrics.setAvailable(r.Free())
	}
	return err
}

// Has returns true if the provided port is already allocated and a call
// to Allocate(port) would fail with ErrAllocated.
func (r *PortAllocator) Has(port int) bool {

			port:   basePortRange + sizePortRange,
			errMsg: fmt.Sprintf("provided port is not in the valid range. The range of valid ports is %d-%d", basePortRange, basePortRange+sizePortRange-1),
		},
		{
			name:   "Allocate invalid port",
			port:   -2,

	// Then generate the per-port passthrough filter chains.
	for port := range b.applier.PortLevelSetting() {
		// Skip the per-port passthrough filterchain if the port is already handled by InboundMTLSConfiguration().
		if !needPerPortPassthroughFilterChain(port, b.proxy) {
			continue
		}

		authnLog.Debugf("InboundMTLSConfiguration: build extra pass through filter chain for %v:%d", b.proxy.ID, port)

		}
	}

	port := instance.ServicePort
	if port == nil {
		errs = multierror.Append(errs, fmt.Errorf("missing service port"))
	} else if instance.Service != nil {
		expected, ok := instance.Service.Ports.Get(port.Name)
		if !ok {
			errs = multierror.Append(errs, fmt.Errorf("missing service port %q", port.Name))
		} else {
			if expected.Port != port.Port {
				errs = multierror.Append(errs,

	"istio.io/istio/pkg/config/visibility"
	"istio.io/istio/pkg/spiffe"
	"istio.io/istio/pkg/util/sets"
)

func convertPort(port corev1.ServicePort) *model.Port {
	return &model.Port{
		Name:     port.Name,
		Port:     int(port.Port),
		Protocol: kube.ConvertProtocol(port.Port, port.Name, port.Protocol, port.AppProtocol),
	}
}

			// If it is the first occurrence of this port, create a ProtocolMap
			if _, ok := portMap[sPort.Port]; !ok {
				portMap[sPort.Port] = ProtocolMap{}
			}

			// Default protocol is TCP
			protocol := sPort.Protocol
			if protocol == "" {
				protocol = core_v1.ProtocolTCP
			}

			// Appending the service information for the Port/Protocol combination