istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pilot/pkg/serviceregistry/util/label/label.go (about)

     1  // Copyright Istio Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package label
    16  
    17  import (
    18  	"strings"
    19  
    20  	"istio.io/api/label"
    21  	"istio.io/istio/pkg/cluster"
    22  	"istio.io/istio/pkg/config/labels"
    23  	"istio.io/istio/pkg/network"
    24  )
    25  
    26  // copied from https://github.com/kubernetes/api/blob/master/core/v1/well_known_labels.go
    27  // It is to remove dependency on k8s.io/api/core/v1
    28  const (
    29  	LabelHostname = "kubernetes.io/hostname"
    30  
    31  	LabelTopologyZone    = "topology.kubernetes.io/zone"
    32  	LabelTopologySubzone = "topology.istio.io/subzone"
    33  	LabelTopologyRegion  = "topology.kubernetes.io/region"
    34  )
    35  
    36  // AugmentLabels adds additional labels to the those provided.
    37  func AugmentLabels(in labels.Instance, clusterID cluster.ID, locality, k8sNode string, networkID network.ID) labels.Instance {
    38  	// Copy the original labels to a new map.
    39  	out := make(labels.Instance, len(in)+6)
    40  	for k, v := range in {
    41  		out[k] = v
    42  	}
    43  
    44  	region, zone, subzone := SplitLocalityLabel(locality)
    45  	if len(region) > 0 {
    46  		out[LabelTopologyRegion] = region
    47  	}
    48  	if len(zone) > 0 {
    49  		out[LabelTopologyZone] = zone
    50  	}
    51  	if len(subzone) > 0 {
    52  		out[label.TopologySubzone.Name] = subzone
    53  	}
    54  	if len(clusterID) > 0 {
    55  		out[label.TopologyCluster.Name] = clusterID.String()
    56  	}
    57  	if len(k8sNode) > 0 {
    58  		out[LabelHostname] = k8sNode
    59  	}
    60  	if len(networkID) > 0 {
    61  		out[label.TopologyNetwork.Name] = networkID.String()
    62  	}
    63  	return out
    64  }
    65  
    66  // SplitLocalityLabel splits a locality label into region, zone and subzone strings.
    67  func SplitLocalityLabel(locality string) (region, zone, subzone string) {
    68  	items := strings.Split(locality, "/")
    69  	switch len(items) {
    70  	case 1:
    71  		return items[0], "", ""
    72  	case 2:
    73  		return items[0], items[1], ""
    74  	default:
    75  		return items[0], items[1], items[2]
    76  	}
    77  }