简介： 本文将介绍如何在 gRPC 分布式场景中，实现 API 的日志跟踪。
介绍
本文将介绍如何在 gRPC 分布式场景中，实现 API 的日志追踪。
什么是 API 日志追踪？一个 API 请求会跨多个微服务，我们希望通过一个唯一的 ID 检索到整个链路的日志。
我们将会使用 rk-boot 来启动 gRPC 服务。
请访问如下地址获取完整教程：
- https://rkdev.info/cn
- RK 文档 (备用)
安装
go get github.com/rookie-ninja/rk-boot快速开始
rk-boot 默认集成了 grpc-gateway，并且会默认启动。
我们会创建 /api/v1/greeter API 进行验证，同时开启 logging, meta 和 tracing 拦截器以达到目的。
1. 创建 api/v1/greeter.proto
syntax = "proto3";package api.v1;option go_package = "api/v1/greeter";service Greeter {rpc Greeter (GreeterRequest) returns (GreeterResponse) {}
}message GreeterRequest {string name = 1;
}message GreeterResponse {string message = 1;
}2. 创建 api/v1/gw_mapping.yaml
type: google.api.Service
config_version: 3# Please refer google.api.Http in https://github.com/googleapis/googleapis/blob/master/google/api/http.proto file for details.
http:rules:- selector: api.v1.Greeter.Greeterget: /api/v1/greeter3. 创建 buf.yaml
version: v1beta1
name: github.com/rk-dev/rk-demo
build:roots:- api4. 创建 buf.gen.yaml
version: v1beta1
plugins:# protoc-gen-go needs to be installed, generate go files based on proto files- name: goout: api/genopt:- paths=source_relative# protoc-gen-go-grpc needs to be installed, generate grpc go files based on proto files- name: go-grpcout: api/genopt:- paths=source_relative- require_unimplemented_servers=false# protoc-gen-grpc-gateway needs to be installed, generate grpc-gateway go files based on proto files- name: grpc-gatewayout: api/genopt:- paths=source_relative- grpc_api_configuration=api/v1/gw_mapping.yaml# protoc-gen-openapiv2 needs to be installed, generate swagger config files based on proto files- name: openapiv2out: api/genopt:- grpc_api_configuration=api/v1/gw_mapping.yaml5. 编译 proto file
$ buf generate如下的文件会被创建。
$ tree api/gen
api/gen
└── v1├── greeter.pb.go├── greeter.pb.gw.go├── greeter.swagger.json└── greeter_grpc.pb.go1 directory, 4 files6. 创建 bootA.yaml & serverA.go
Server-A 监听 1949 端口，并且发送请求给 Server-B。
我们通过 rkgrpcctx.InjectSpanToNewContext() 方法把 Tracing 信息注入到 Context 中，发送给 Server-B。
---
grpc:- name: greeter # Name of grpc entryport: 1949 # Port of grpc entryenabled: true # Enable grpc entryinterceptors:loggingZap:enabled: truemeta:enabled: truetracingTelemetry:enabled: truepackage mainimport ("context""demo/api/gen/v1""fmt""github.com/rookie-ninja/rk-boot""github.com/rookie-ninja/rk-grpc/interceptor/context""google.golang.org/grpc"
)// Application entrance.
func main() {// Create a new boot instance.boot := rkboot.NewBoot(rkboot.WithBootConfigPath("bootA.yaml"))// Get grpc entry with namegrpcEntry := boot.GetGrpcEntry("greeter")grpcEntry.AddRegFuncGrpc(registerGreeter)grpcEntry.AddRegFuncGw(greeter.RegisterGreeterHandlerFromEndpoint)// Bootstrapboot.Bootstrap(context.Background())// Wait for shutdown sigboot.WaitForShutdownSig(context.Background())
}func registerGreeter(server *grpc.Server) {greeter.RegisterGreeterServer(server, &GreeterServer{})
}type GreeterServer struct{}func (server *GreeterServer) Greeter(ctx context.Context, request *greeter.GreeterRequest) (*greeter.GreeterResponse, error) {// Call serverB at 2008 with grpc clientopts := []grpc.DialOption{grpc.WithBlock(),grpc.WithInsecure(),}conn, _ := grpc.Dial("localhost:2008", opts...)defer conn.Close()client := greeter.NewGreeterClient(conn)// Inject current trace information into contextnewCtx := rkgrpcctx.InjectSpanToNewContext(ctx)client.Greeter(newCtx, &greeter.GreeterRequest{Name: "A"})return &greeter.GreeterResponse{Message: fmt.Sprintf("Hello %s!", request.Name),}, nil
}7. 创建 bootB.yaml & serverB.go
Server-B 监听 2008 端口。
---
grpc:- name: greeter # Name of grpc entryport: 2008 # Port of grpc entryenabled: true # Enable grpc entryinterceptors:loggingZap:enabled: truemeta:enabled: truetracingTelemetry:enabled: truepackage mainimport ("context""demo/api/gen/v1""fmt""github.com/rookie-ninja/rk-boot""google.golang.org/grpc"
)// Application entrance.
func main() {// Create a new boot instance.boot := rkboot.NewBoot(rkboot.WithBootConfigPath("bootB.yaml"))// Get grpc entry with namegrpcEntry := boot.GetGrpcEntry("greeter")grpcEntry.AddRegFuncGrpc(registerGreeterB)grpcEntry.AddRegFuncGw(greeter.RegisterGreeterHandlerFromEndpoint)// Bootstrapboot.Bootstrap(context.Background())// Wait for shutdown sigboot.WaitForShutdownSig(context.Background())
}func registerGreeterB(server *grpc.Server) {greeter.RegisterGreeterServer(server, &GreeterServerB{})
}type GreeterServerB struct{}func (server *GreeterServerB) Greeter(ctx context.Context, request *greeter.GreeterRequest) (*greeter.GreeterResponse, error) {return &greeter.GreeterResponse{Message: fmt.Sprintf("Hello %s!", request.Name),}, nil
}8. 文件夹结构
├── api
│ ├── gen
│ │ └── v1
│ │ ├── greeter.pb.go
│ │ ├── greeter.pb.gw.go
│ │ ├── greeter.swagger.json
│ │ └── greeter_grpc.pb.go
│ └── v1
│ ├── greeter.proto
│ └── gw_mapping.yaml
├── bootA.yaml
├── bootB.yaml
├── buf.gen.yaml
├── buf.yaml
├── go.mod
├── go.sum
├── serverA.go
└── serverB.go9. 启动 ServerA & ServerB
$ go run serverA.go
$ go run serverB.go10. 往 ServerA 发送请求
¥ curl "localhost:1949/api/v1/greeter?name=rk-dev"11. 验证日志
两个服务的日志中，会有同样的 traceId，不同的 requestId。
我们可以通过 grep traceId 来追踪 RPC。
- ServerA
------------------------------------------------------------------------
endTime=2021-10-20T00:02:21.739688+08:00
...
ids={"eventId":"0d145356-998a-4999-ab62-6f1b805274a0","requestId":"0d145356-998a-4999-ab62-6f1b805274a0","traceId":"c36a45eb076066df39fa407174012369"}
...
operation=/api.v1.Greeter/Greeter
resCode=OK
eventStatus=Ended
EOE- ServerB
------------------------------------------------------------------------
endTime=2021-10-20T00:02:21.739125+08:00
...
ids={"eventId":"8858a6eb-e953-42ad-bdc3-c466bbbd798e","requestId":"8858a6eb-e953-42ad-bdc3-c466bbbd798e","traceId":"c36a45eb076066df39fa407174012369"}
...
operation=/api.v1.Greeter/Greeter
resCode=OK
eventStatus=Ended
EOE概念
当我们没有使用例如 jaeger 调用链服务的时候，我们希望通过日志来追踪分布式系统里的 RPC 请求。
rk-boot 的拦截器会通过 openTelemetry 库来向日志写入 traceId 来追踪 RPC。
当启动了日志拦截器，原数据拦截器，调用链拦截器的时候，拦截器会往日志里写入如下三种 ID。
EventId
当启动了日志拦截器，EventId 会自动生成。
---
grpc:- name: greeter # Name of grpc entryport: 1949 # Port of grpc entryenabled: true # Enable grpc entryinterceptors:loggingZap:enabled: true------------------------------------------------------------------------
...
ids={"eventId":"cd617f0c-2d93-45e1-bef0-95c89972530d"}
...RequestId
当启动了日志拦截器和原数据拦截器，RequestId 和 EventId 会自动生成，并且这两个 ID 会一致。
---
grpc:- name: greeter # Name of grpc entryport: 1949 # Port of grpc entryenabled: true # Enable grpc entryinterceptors:loggingZap:enabled: truemeta:enabled: true------------------------------------------------------------------------
...
ids={"eventId":"8226ba9b-424e-4e19-ba63-d37ca69028b3","requestId":"8226ba9b-424e-4e19-ba63-d37ca69028b3"}
...即使用户覆盖了 RequestId，EventId 也会保持一致。
rkgrpcctx.AddHeaderToClient(ctx, rkgrpcctx.RequestIdKey, "overridden-request-id")------------------------------------------------------------------------
...
ids={"eventId":"overridden-request-id","requestId":"overridden-request-id"}
...TraceId
当启动了调用链拦截器，traceId 会自动生成。
---
grpc:- name: greeter # Name of grpc entryport: 1949 # Port of grpc entryenabled: true # Enable grpc entryinterceptors:loggingZap:enabled: truemeta:enabled: truetracingTelemetry:enabled: true------------------------------------------------------------------------
...
ids={"eventId":"dd19cf9a-c7be-486c-b29d-7af777a78ebe","requestId":"dd19cf9a-c7be-486c-b29d-7af777a78ebe","traceId":"316a7b475ff500a76bfcd6147036951c"}
...原文链接
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