Polaris2Istio的实现和说明

2022-08-30 约 583 字预计阅读 2 分钟

背景

如融合、扩展Service Mesh文中所述，为了让第三方服务发现的服务能够接入到Istio服务网格当中，我设计开放一个名为Polaris2Istio的组件。

设计图

时序图

sequenceDiagram actor Operator participant Polaris2Istio participant Polaris participant ApiServer participant CoreDNS Operator->>ApiServer: Create the ServiceEntry for the polairs' service with manager labels. ApiServer->>CoreDNS: Create the CNAME record. Operator->>Polaris2Istio: Config the manage policy. loop Watch ApiServer Polaris2Istio->>ApiServer: Get the matched services for manager. ApiServer-->>Polaris2Istio: Back the services. Polaris2Istio->>ApiServer: Update the services' configuration(Instances' ip). end loop Watch polaris Polaris2Istio->>Polaris: Watch the polaris service's event. Polaris-->>Polaris2Istio: Send the event to the polaris2sitio. Polaris2Istio->>ApiServer: Sync the polaris service's message to the k8s service. end

使用方式

编译

1

make build

运行

1

polaris2istio --polarisAddress <polarishost:port>

配置

模式 1. 基于ServiceEntry的管理标签筛选同步Polaris实例:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16


apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: <polaris-name-for-k8s>
  namespace: polaris
  annotations:
    aeraki.net/polarisNamespace: Test
    aeraki.net/polarisService: test-service
    aeraki.net/external: "false"
  labels:
    manager: aeraki
    registry: polaris
spec:
  hosts:
    - dev.<polaris-name-for-k8s>.polaris
  resolution: NONE # or STATIC

详细说明请参考：https://github.com/aeraki-mesh/polaris2istio

心得技巧

保持分配好的VIP

 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125


// polaris2istio/pkg/serviceregistry/polaris/watcher/provider.go 
func (w *ProviderWatcher) syncPolarisServices2Istio(polarisInfo *model.PolarisInfo) {
	klog.Infof("[syncPolarisServices2Istio] polarisInfo: %v", polarisInfo)
	rsp, err := w.polarisclient.GetPolarisAllInstances(polarisInfo.PolarisNamespace, polarisInfo.PolarisService)
	if err != nil {
		klog.Errorf("[syncPolarisServices2Istio] query polaris services' instances failed, err: %v", err.Error())
		return
	}

	newServiceEntry, newAnnotations := model.ConvertServiceEntry(rsp, polarisInfo)
	if newServiceEntry == nil {
		klog.Errorf("convertServiceEntry failed?")
		return
	}

	oldServiceEntry, err := w.ic.NetworkingV1alpha3().ServiceEntries(w.configRootNS).Get(context.TODO(), model.CovertServiceName(polarisInfo.PolarisNamespace, polarisInfo.PolarisService), v1.GetOptions{})
	if err != nil {
		klog.Infof("[syncPolarisServices2Istio] get old service entries failed, error: %v", err)
		return
	}

	newServiceEntry.Addresses = append(newServiceEntry.Addresses, oldServiceEntry.Spec.GetAddresses()...)

	if revision, exists := oldServiceEntry.GetAnnotations()["aeraki.net/revision"]; !exists || newAnnotations["aeraki.net/revision"] != revision {
		klog.Infof("[syncPolarisServices2Istio] update serviceentry: %v", newServiceEntry)
		_, err = w.ic.NetworkingV1alpha3().ServiceEntries(oldServiceEntry.Namespace).Update(context.TODO(),
			w.toServiceEntryCRD(model.CovertServiceName(polarisInfo.PolarisNamespace, polarisInfo.PolarisService), newServiceEntry, oldServiceEntry, newAnnotations),
			v1.UpdateOptions{FieldManager: aerakiFieldManager})
		if err != nil {
			klog.Errorf("failed to update ServiceEntry: %s", err.Error())
		}
	} else {
		log.Infof("[syncPolarisServices2Istio] serviceentry unchanged: %v", oldServiceEntry.GetName())
	}
}

代码

注意事项

只对polaris命名空间中的ServiceEntrys同步；
在集群中运行时需要为其配置权限策略；
开源版本的polaris sdk是需要手动设置polaris地址的，与内部版不同；

目录