流量管理
流量管理
在本节中，我们将延续上一个任务【在 Istio 环境部署 Dubbo-go 应用】。
在之前的任务中，我们在集群中部署了一组 Dubbo-go Server和 Client 端应用，验证了服务发现和调用成功。在本节中，我们将创建新版本的 Server 端应用。通过配置 VirtualService 和 DestinationRule ，实现路由管理，和流量转移能力
1. 准备工作
- dubbo-go cli 工具和依赖工具已安装、grpc_cli (如需本地调试)。
- docker、helm、kubectl 环境已安装。（arm 机器需支持 docker buildx）
- 任务【在 Istio 环境部署 Dubbo-go 应用】已完成
2. 开发多版本Dubbo-go 应用。
2.1 使用 dubbogo-cli 创建另一个项目模板
$ dubbogo-cli newApp .
2.2 开发和部署客户端 Dubbo-go 应用 v2：
编写业务逻辑
- 修改 package/service/service.go 的实现方法，返回版本号为 v2.0.0
func (s *GreeterServerImpl) SayHello(ctx context.Context, in *api.HelloRequest) (*api.User, error) {
return &api.User{Name: "Hello " + in.Name, Id: "v2.0.0"}, nil
}
修改如下配置文件，使用xds协议作为注册中心，加载名为 GreeterServerImpl 的服务结构。
conf/dubbogo.yaml
dubbo: registries: xds: protocol: xds address: istiod.istio-system.svc.cluster.local:15010 protocols: triple: name: tri port: 20000 provider: services: GreeterServerImpl: interface: "" # read from stub至此，应用开发完成。
配置构建和部署参数
指定需要构建的镜像：
修改 Makefile 如下字段，指定好需要构建的镜像地址和版本，我们把镜像 tag 改为 2.0.0。
指定好需要通过 helm 安装的名称。
IMAGE = xxx/dubbo-go-server TAG = 2.0.0 HELM_INSTALL_NAME = dubbo-go-server指定需要部署的应用和镜像：
修改 chart/app/Chart.yaml 如下字段，指定当前应用名为
dubbo-go-server，我们在创建v1版本服务的时候，已经有了该应用的 service，这次部署时模板将不会创建 service。apiVersion: v1 name: dubbo-go-server description: dubbo-go-server修改 chart/app/values.yaml 如下字段，指定需要部署的镜像为2.0.0，以及当前开发的应用版本 dubbogoAppVersion 为 v2。
部署的镜像需要和上述构建的镜像一致。当前应用版本用于 mesh 流量规则控制。
image: repository: xxx/dubbo-go-server pullPolicy: Always tag: "2.0.0" # Dubbo-go-mesh version control labels version: labels: dubbogoAppVersion: v2至此，构建参数和发布参数都已指定好，可以进行构建和部署了。
使用模板构建和部署 Dubbo-go 应用
构建、推送镜像
$ make build(本地为 amd64机器)或者
$ make buildx-publish(本地为 arm64机器，依赖 docker buildx 命令)发布 Dubbo-go Server v2 至集群
$ make deploy NAME: dubbo-go-server-v2 LAST DEPLOYED: Thu Apr 7 12:29:28 2022 NAMESPACE: default STATUS: deployed REVISION: 1 TEST SUITE: None $ helm list NAME NAMESPACE REVISION UPDATED STATUS CHART dubbo-go-client default 1 2022-04-07 11:49:55.517898 +0800 CST deployed dubbo-go-client-0.0.1 1.16.0 dubbo-go-server-v1 default 1 2022-04-07 11:23:18.397658 +0800 CST deployed dubbo-go-server-0.0.1 1.16.0 dubbo-go-server-v2 default 1 2022-04-07 12:29:28.497476 +0800 CST deployed dubbo-go-client-0.0.1 1.16.0可看到通过 helm 部署成功, 目前已经在集群中存在一个 Client 应用，和 Server 的两个版本。
2.3 验证应用
查看资源部署情况
查看部署好的 deployment ，server 包含了两个版本。
$ kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
dubbo-go-client-v1 1/1 1 1 40m
dubbo-go-server-v2 1/1 1 1 77s
dubbo-go-server-v1 1/1 1 1 67m
查看部署好的 service。两个版本的deployment 共用同一个 service。
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
dubbo-go-client ClusterIP 192.168.8.176 <none> 20000/TCP 41m
dubbo-go-server ClusterIP 192.168.216.253 <none> 20000/TCP 67m
查看 Client 应用日志，验证请求调用到了两个版本的应用上。
$ kubectl get pods | grep client | awk '{print $1}' | xargs kubectl logs
...
2022-04-07T05:06:40.384Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:06:41.386Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:06:42.388Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:06:43.389Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:06:44.390Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:06:45.392Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:06:46.393Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:06:47.394Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:06:48.396Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:06:49.397Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
至此，我们开发并且部署成功了多版本应用。
3. 配置请求路由
3.1 配置目标规则
执行以下命令以创建目标规则，该目标规则将 dubbo-go-server 细分为两个子集。v1和 v2
$ kubectl apply -f destinationrule.yaml
destinationrule.yaml 内容：
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: dubbo-go-server
spec:
host: dubbo-go-server
subsets:
- name: v1
labels:
dubbogoAppVersion: v1 # 对应应用模板中 chart/app/values.yaml 中指定的版本标签
- name: v2
labels:
dubbogoAppVersion: v2
3.2 应用 Virtual Service
执行以下命令以创建路由，该路由将所有流量都路由至v1 版本应用。
$ kubectl apply -f virtualservice.yaml
virtualservice.yaml 内容
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: dubbo-go-server
spec:
hosts:
- dubbo-go-server
http:
- route:
- destination:
host: dubbo-go-server
subset: v1
3.3 验证路由生效
所有流量将流向 v1 版本应用。
$ kubectl get pods | grep client | awk '{print $1}' | xargs kubectl logs
...
2022-04-07T05:40:44.353Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:40:45.354Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:40:46.356Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:40:47.357Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:40:48.359Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:40:49.361Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
4. 基于用户身份的路由
有了上述多版本应用路由的基础，我们可以通过一些策略，来进行灵活的流量管理。
4.1 为客户端应用增加用户身份标识
我们希望拥有 user: admin 标识的流量都可以体验 v2 新版本应用。
回到之前创建的 dubbo-go-client 项目，修改 cmd/app.go 的 main 函数，增加调用标识：user: admin。
func main() {
client := &api.GreeterClientImpl{}
config.SetConsumerService(client)
if err := config.Load(); err != nil {
panic(err)
}
request := &api.HelloRequest{
Name: "laurence",
}
for{
ctx := context.Background()
ctx = context.WithValue(ctx, constant.AttachmentKey, map[string]string{
"user":"admin", // 使用上下文 context 为调用增加标识
})
if rsp, err := client.SayHello(ctx, request); err != nil{
logger.Errorf("call server error = %s", err)
}else{
logger.Infof("call server response = %+v", rsp)
}
time.Sleep(time.Second)
}
}
构建、推送镜像，覆盖之前的提交。您也可以升级一下发布的镜像版本。
$ make build(本地为 amd64机器)或者
$ make buildx-publish(本地为 arm64机器，依赖 docker buildx 命令)删除 dubbo-go-client 应用
$ make remove helm uninstall dubbo-go-client release "dubbo-go-client" uninstalled重新发布应用。
$ make deploy发布后，验证调用成功，由于前面进行了路由配置。所有流量都流向 v1 版本。
$ kubectl get pods | grep client | awk '{print $1}' | xargs kubectl logs ... 2022-04-07T05:40:44.353Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0" 2022-04-07T05:40:45.354Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0" 2022-04-07T05:40:46.356Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0" 2022-04-07T05:40:47.357Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0" 2022-04-07T05:40:48.359Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0" 2022-04-07T05:40:49.361Z INFO cmd/app.go:29 call server response = name:"Hello laurence" id:"v1.0.0"
4.2 创建基于用户身份的路由
执行以下命令以修改/创建路由，该路由将所有请求头存在 user: admin 标识的流量都路由至 v2 版本。
$ kubectl apply -f virtualservice.yaml
virtualservice.yaml 内容
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: dubbo-go-server
spec:
hosts:
- dubbo-go-server
http:
- match:
- headers:
user:
exact: admin
route:
- destination:
host: dubbo-go-server
subset: v2
- route:
- destination:
host: dubbo-go-server
subset: v1
4.3 验证路由生效
所有流量将流向 v2 版本应用。
$ kubectl get pods | grep client | awk '{print $1}' | xargs kubectl logs
...
2022-04-07T05:52:18.714Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:52:19.716Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:52:20.717Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:52:21.718Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:52:22.720Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:52:23.722Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:52:24.723Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
5. 基于权重的路由
5.1 创建基于权重的路由
延续上述任务，我们执行以下命令以修改/创建路由，该路由将流量的 10% 导入新版本应用，进行灰度测试。
$ kubectl apply -f virtualservice.yaml
virtualservice.yaml 内容
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: dubbo-go-server
spec:
hosts:
- dubbo-go-server
http:
- route:
- destination:
host: dubbo-go-server
subset: v1
weight: 90
- destination:
host: dubbo-go-server
subset: v2
weight: 10
5.2 验证路由生效
少数流量将流向 v2 版本。
$ kubectl get pods | grep client | awk '{print $1}' | xargs kubectl logs
...
2022-04-07T05:55:52.035Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:53.036Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:54.037Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:55.039Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:56.041Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:57.043Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:58.045Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:55:59.047Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:56:00.049Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:56:01.050Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v2.0.0"
2022-04-07T05:56:02.053Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
2022-04-07T05:56:03.055Z INFO cmd/app.go:35 call server response = name:"Hello laurence" id:"v1.0.0"
最后修改 March 2, 2023: Fix alias forward in docs3-v2 (#2342) (f16c153559)
