istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pkg/config/mesh/kubemesh/watcher.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 kubemesh
    16  
    17  import (
    18  	"fmt"
    19  
    20  	v1 "k8s.io/api/core/v1"
    21  
    22  	meshconfig "istio.io/api/mesh/v1alpha1"
    23  	"istio.io/istio/pkg/config/mesh"
    24  	"istio.io/istio/pkg/kube"
    25  	"istio.io/istio/pkg/kube/watcher/configmapwatcher"
    26  	"istio.io/istio/pkg/log"
    27  )
    28  
    29  // NewConfigMapWatcher creates a new Watcher for changes to the given ConfigMap.
    30  func NewConfigMapWatcher(client kube.Client, namespace, name, key string, multiWatch bool, stop <-chan struct{}) *mesh.MultiWatcher {
    31  	w := mesh.NewMultiWatcher(mesh.DefaultMeshConfig())
    32  	c := configmapwatcher.NewController(client, namespace, name, func(cm *v1.ConfigMap) {
    33  		meshNetworks, err := ReadNetworksConfigMap(cm, "meshNetworks")
    34  		if err != nil {
    35  			// Keep the last known config in case there's a misconfiguration issue.
    36  			log.Errorf("failed to read meshNetworks config from ConfigMap: %v", err)
    37  			return
    38  		}
    39  		if meshNetworks != nil {
    40  			w.SetNetworks(meshNetworks)
    41  		}
    42  		if multiWatch {
    43  			meshConfig := meshConfigMapData(cm, key)
    44  			w.HandleMeshConfigData(meshConfig)
    45  			return
    46  		}
    47  		// Original behavior - just per-revision config
    48  		meshConfig, err := ReadConfigMap(cm, key)
    49  		if err != nil {
    50  			// Keep the last known config in case there's a misconfiguration issue.
    51  			log.Errorf("failed to read mesh config from ConfigMap: %v", err)
    52  			return
    53  		}
    54  		w.HandleMeshConfig(meshConfig)
    55  	})
    56  
    57  	go c.Run(stop)
    58  
    59  	// Ensure the ConfigMap is initially loaded if present.
    60  	if !client.WaitForCacheSync("configmap watcher", stop, c.HasSynced) {
    61  		log.Error("failed to wait for cache sync")
    62  	}
    63  	return w
    64  }
    65  
    66  func AddUserMeshConfig(client kube.Client, watcher mesh.Watcher, namespace, key, userMeshConfig string, stop <-chan struct{}) {
    67  	c := configmapwatcher.NewController(client, namespace, userMeshConfig, func(cm *v1.ConfigMap) {
    68  		meshConfig := meshConfigMapData(cm, key)
    69  		watcher.HandleUserMeshConfig(meshConfig)
    70  	})
    71  
    72  	go c.Run(stop)
    73  	if !client.WaitForCacheSync("user mesh config", stop, c.HasSynced) {
    74  		log.Error("failed to wait for cache sync")
    75  	}
    76  }
    77  
    78  func meshConfigMapData(cm *v1.ConfigMap, key string) string {
    79  	if cm == nil {
    80  		return ""
    81  	}
    82  
    83  	cfgYaml, exists := cm.Data[key]
    84  	if !exists {
    85  		return ""
    86  	}
    87  
    88  	return cfgYaml
    89  }
    90  
    91  func ReadConfigMap(cm *v1.ConfigMap, key string) (*meshconfig.MeshConfig, error) {
    92  	if cm == nil {
    93  		log.Info("no ConfigMap found, using default MeshConfig config")
    94  		return mesh.DefaultMeshConfig(), nil
    95  	}
    96  
    97  	cfgYaml, exists := cm.Data[key]
    98  	if !exists {
    99  		return nil, fmt.Errorf("missing ConfigMap key %q", key)
   100  	}
   101  
   102  	meshConfig, err := mesh.ApplyMeshConfigDefaults(cfgYaml)
   103  	if err != nil {
   104  		return nil, fmt.Errorf("failed reading MeshConfig config: %v. YAML:\n%s", err, cfgYaml)
   105  	}
   106  
   107  	log.Info("Loaded MeshConfig config from Kubernetes API server.")
   108  	return meshConfig, nil
   109  }
   110  
   111  func ReadNetworksConfigMap(cm *v1.ConfigMap, key string) (*meshconfig.MeshNetworks, error) {
   112  	if cm == nil {
   113  		log.Info("no ConfigMap found, using existing MeshNetworks config")
   114  		return nil, nil
   115  	}
   116  
   117  	cfgYaml, exists := cm.Data[key]
   118  	if !exists {
   119  		return nil, nil
   120  	}
   121  
   122  	meshNetworks, err := mesh.ParseMeshNetworks(cfgYaml)
   123  	if err != nil {
   124  		return nil, fmt.Errorf("failed reading MeshNetworks config: %v. YAML:\n%s", err, cfgYaml)
   125  	}
   126  
   127  	log.Info("Loaded MeshNetworks config from Kubernetes API server.")
   128  	return meshNetworks, nil
   129  }