sigs.k8s.io/external-dns@v0.14.1/source/targetfiltersource.go (about)

     1  /*
     2  Copyright 2017 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package source
    18  
    19  import (
    20  	"context"
    21  
    22  	log "github.com/sirupsen/logrus"
    23  
    24  	"sigs.k8s.io/external-dns/endpoint"
    25  )
    26  
    27  // targetFilterSource is a Source that removes endpoints matching the target filter from its wrapped source.
    28  type targetFilterSource struct {
    29  	source       Source
    30  	targetFilter endpoint.TargetFilterInterface
    31  }
    32  
    33  // NewTargetFilterSource creates a new targetFilterSource wrapping the provided Source.
    34  func NewTargetFilterSource(source Source, targetFilter endpoint.TargetFilterInterface) Source {
    35  	return &targetFilterSource{source: source, targetFilter: targetFilter}
    36  }
    37  
    38  // Endpoints collects endpoints from its wrapped source and returns
    39  // them without targets matching the target filter.
    40  func (ms *targetFilterSource) Endpoints(ctx context.Context) ([]*endpoint.Endpoint, error) {
    41  	result := []*endpoint.Endpoint{}
    42  
    43  	endpoints, err := ms.source.Endpoints(ctx)
    44  	if err != nil {
    45  		return nil, err
    46  	}
    47  
    48  	for _, ep := range endpoints {
    49  		filteredTargets := []string{}
    50  
    51  		for _, t := range ep.Targets {
    52  			if ms.targetFilter.Match(t) {
    53  				filteredTargets = append(filteredTargets, t)
    54  			}
    55  		}
    56  
    57  		// If all targets are filtered out, skip the endpoint.
    58  		if len(filteredTargets) == 0 {
    59  			log.WithField("endpoint", ep).Debugf("Skipping endpoint because all targets were filtered out")
    60  			continue
    61  		}
    62  
    63  		ep.Targets = filteredTargets
    64  
    65  		result = append(result, ep)
    66  	}
    67  
    68  	return result, nil
    69  }
    70  
    71  func (ms *targetFilterSource) AddEventHandler(ctx context.Context, handler func()) {
    72  	ms.source.AddEventHandler(ctx, handler)
    73  }