istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pkg/kube/multicluster/component.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 multicluster
    16  
    17  import (
    18  	"sync"
    19  
    20  	"istio.io/istio/pkg/cluster"
    21  	"istio.io/istio/pkg/kube/controllers"
    22  	"istio.io/istio/pkg/kube/kclient"
    23  	"istio.io/istio/pkg/kube/kubetypes"
    24  	"istio.io/istio/pkg/maps"
    25  	"istio.io/istio/pkg/slices"
    26  )
    27  
    28  type ComponentConstraint interface {
    29  	Close()
    30  	HasSynced() bool
    31  }
    32  
    33  type Component[T ComponentConstraint] struct {
    34  	mu          sync.RWMutex
    35  	constructor func(cluster *Cluster) T
    36  	clusters    map[cluster.ID]T
    37  }
    38  
    39  func (m *Component[T]) ForCluster(clusterID cluster.ID) *T {
    40  	m.mu.RLock()
    41  	defer m.mu.RUnlock()
    42  	t, f := m.clusters[clusterID]
    43  	if !f {
    44  		return nil
    45  	}
    46  	return &t
    47  }
    48  
    49  func (m *Component[T]) All() []T {
    50  	m.mu.RLock()
    51  	defer m.mu.RUnlock()
    52  	return maps.Values(m.clusters)
    53  }
    54  
    55  func (m *Component[T]) clusterAdded(cluster *Cluster) ComponentConstraint {
    56  	comp := m.constructor(cluster)
    57  	m.mu.Lock()
    58  	defer m.mu.Unlock()
    59  	m.clusters[cluster.ID] = comp
    60  	return comp
    61  }
    62  
    63  func (m *Component[T]) clusterUpdated(cluster *Cluster) ComponentConstraint {
    64  	// Build outside of the lock, in case its slow
    65  	comp := m.constructor(cluster)
    66  	old, f := m.clusters[cluster.ID]
    67  	m.mu.Lock()
    68  	m.clusters[cluster.ID] = comp
    69  	m.mu.Unlock()
    70  	// Close outside of the lock, in case its slow
    71  	if f {
    72  		old.Close()
    73  	}
    74  	return comp
    75  }
    76  
    77  func (m *Component[T]) clusterDeleted(cluster cluster.ID) {
    78  	m.mu.Lock()
    79  	defer m.mu.Unlock()
    80  	// If there is an old one, close it
    81  	if old, f := m.clusters[cluster]; f {
    82  		old.Close()
    83  	}
    84  	delete(m.clusters, cluster)
    85  }
    86  
    87  func (m *Component[T]) HasSynced() bool {
    88  	for _, c := range m.All() {
    89  		if !c.HasSynced() {
    90  			return false
    91  		}
    92  	}
    93  	return true
    94  }
    95  
    96  type KclientComponent[T controllers.ComparableObject] struct {
    97  	internal *Component[kclientInternalComponent[T]]
    98  }
    99  
   100  type kclientInternalComponent[T controllers.ComparableObject] struct {
   101  	client kclient.Client[T]
   102  }
   103  
   104  func (k kclientInternalComponent[T]) Close() {
   105  	k.client.ShutdownHandlers()
   106  }
   107  
   108  func (k kclientInternalComponent[T]) HasSynced() bool {
   109  	return k.client.HasSynced()
   110  }
   111  
   112  // BuildMultiClusterKclientComponent builds a simple Component that just wraps a single kclient.Client
   113  func BuildMultiClusterKclientComponent[T controllers.ComparableObject](c ComponentBuilder, filter kubetypes.Filter) *KclientComponent[T] {
   114  	res := BuildMultiClusterComponent[kclientInternalComponent[T]](c, func(cluster *Cluster) kclientInternalComponent[T] {
   115  		return kclientInternalComponent[T]{kclient.NewFiltered[T](cluster.Client, filter)}
   116  	})
   117  	return &KclientComponent[T]{res}
   118  }
   119  
   120  // ForCluster returns the client for the requests cluster
   121  // Note: this may return nil.
   122  func (m *KclientComponent[T]) ForCluster(clusterID cluster.ID) kclient.Client[T] {
   123  	c := m.internal.ForCluster(clusterID)
   124  	if c == nil {
   125  		return nil
   126  	}
   127  	return c.client
   128  }
   129  
   130  func (m *KclientComponent[T]) All() []kclient.Client[T] {
   131  	return slices.Map(m.internal.All(), func(e kclientInternalComponent[T]) kclient.Client[T] {
   132  		return e.client
   133  	})
   134  }