go微服務框架kratos學習筆記一(kratos demo)

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kratos微服務框架學習筆記一(kratos-demo)

TAG:本系列筆記以demo爲主，適合微服務初學者入門，如果有地方我沒具體寫的話，那肯定是我也沒去看，一筆帶過了，所以很多細節可能還是需要自行研究哦 ! 補的話，得看時機，除非不恰飯哈。

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常見微服務框架主要有這麼幾個

gizmo, a microservice toolkit from The New York Times ★
go-micro, a microservices client/server library ★
gotalk, async peer communication protocol & library
Kite, a micro-service framework
gocircuit, dynamic cloud orchestration
Kratos,bilibili開源的一套Go微服務框架，包含大量微服務相關框架及工具。

這裏有一篇關於kit,go-mirco,gizmo,Kite的比較：

Go 微服務框架對比：Go Micro, Go Kit, Gizmo, Kite

我打算最先看看的框架是kratos，也不爲什麼，因爲喜歡b站(#^.#)。

github上關於kratos的介紹：

名字來源於:《戰神》遊戲以希臘神話爲背景，講述由凡人成爲戰神的奎託斯（Kratos）成爲戰神並展開弒神屠殺的冒險歷程。

目標
致力於提供完整的微服務研發體驗，整合相關框架及工具後，微服務治理相關部分可對整體業務開發週期無感，從而更加聚焦於業務交付。對每位開發者而言，整套Kratos框架也是不錯的學習倉庫，可以瞭解和參考到bilibili在微服務方面的技術積累和經驗。

Features
HTTP Blademaster：核心基於gin進行模塊化設計，簡單易用、核心足夠輕量；
GRPC Warden：基於官方gRPC開發，集成discovery服務發現，並融合P2C負載均衡；
Cache：優雅的接口化設計，非常方便的緩存序列化，推薦結合代理模式overlord；
Database：集成MySQL/HBase/TiDB，添加熔斷保護和統計支持，可快速發現數據層壓力；
Config：方便易用的paladin sdk，可配合遠程配置中心，實現配置版本管理和更新；
Log：類似zap的field實現高性能日誌庫，並結合log-agent實現遠程日誌管理；
Trace：基於opentracing，集成了全鏈路trace支持（gRPC/HTTP/MySQL/Redis/Memcached）；
Kratos Tool：工具鏈，可快速生成標準項目，或者通過Protobuf生成代碼，非常便捷使用gRPC、HTTP、swagger文檔；

kratos本體

先拉代碼

如果下不動可以試試配置下代理

記得打開 go111module

kratos本體

類似於go命令，可以執行各種子工具，如go build、 go tool : kratos build 、kratos run

C:\server\src\test-src\Go_Test\kratos>kratos -h
NAME:
   kratos - kratos工具集

USAGE:
   kratos [global options] command [command options] [arguments...]

VERSION:
   0.3.1

COMMANDS:
   new, n        創建新項目
   build, b      kratos build
   run, r        kratos run
   tool, t       kratos tool
   version, v    kratos version
   self-upgrade  kratos self-upgrade
   help, h       Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --help, -h     show help
   --version, -v  print the version

C:\server\src\test-src\Go_Test\kratos>kratos version
 Version:      0.3.1
 Go version:   go1.13.5
 Built:        2019/11/06
 OS/Arch:      windows/amd64

demo

Quick start

Requirments
Go version>=1.13

Installation

GO111MODULE=on && go get -u github.com/bilibili/kratos/tool/kratos
cd $GOPATH/src
kratos new kratos-demo
通過 kratos new 會快速生成基於kratos庫的腳手架代碼，如生成 kratos-demo

Build & Run

cd kratos-demo/cmd
go build
./cmd -conf …/configs
打開瀏覽器訪問：http://localhost:8000/kratos-demo/start，你會看到輸出了Golang 大法好 ！！！

官方介紹的有點簡潔，咱們動手一步步來：

先進入$GOPATH/src 目錄

kratos new demo

C:\server\src\go\src>kratos new demo
go get -u github.com/bilibili/kratos/tool/kratos-gen-project
go: finding golang.org/x/sys latest
go: finding golang.org/x/crypto latest
genproject: 安裝成功!
go: finding github.com/bilibili/kratos master
go: downloading github.com/bilibili/kratos v0.3.2-0.20191216053608-e8e05452b3b0
go: downloading google.golang.org/grpc v1.24.0
go: extracting google.golang.org/grpc v1.24.0
go: extracting github.com/bilibili/kratos v0.3.2-0.20191216053608-e8e05452b3b0
go: downloading golang.org/x/net v0.0.0-20191011234655-491137f69257
go: extracting golang.org/x/net v0.0.0-20191011234655-491137f69257
go: downloading github.com/prometheus/client_golang v1.1.0
go: downloading github.com/go-sql-driver/mysql v1.4.1
go: downloading github.com/fsnotify/fsnotify v1.4.7
go: downloading google.golang.org/genproto v0.0.0-20191009194640-548a555dbc03
go: downloading gopkg.in/go-playground/validator.v9 v9.29.1
go: downloading github.com/shirou/gopsutil v2.19.6+incompatible
go: extracting github.com/go-sql-driver/mysql v1.4.1
go: extracting github.com/prometheus/client_golang v1.1.0
go: extracting gopkg.in/go-playground/validator.v9 v9.29.1
go: extracting github.com/fsnotify/fsnotify v1.4.7
go: downloading github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2
go: downloading github.com/gogo/protobuf v1.3.0
go: extracting github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2
go: downloading github.com/go-playground/universal-translator v0.16.0
go: extracting github.com/go-playground/universal-translator v0.16.0
go: extracting google.golang.org/genproto v0.0.0-20191009194640-548a555dbc03
go: extracting github.com/gogo/protobuf v1.3.0
go: downloading github.com/go-playground/locales v0.12.1
go: downloading github.com/prometheus/common v0.6.0
go: downloading github.com/leodido/go-urn v1.1.0
go: extracting github.com/prometheus/common v0.6.0
go: extracting github.com/leodido/go-urn v1.1.0
go: downloading github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
go: downloading github.com/matttproud/golang_protobuf_extensions v1.0.1
go: extracting github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
go: extracting github.com/matttproud/golang_protobuf_extensions v1.0.1
go: downloading github.com/beorn7/perks v1.0.1
go: extracting github.com/go-playground/locales v0.12.1
go: extracting github.com/beorn7/perks v1.0.1
go get -u github.com/bilibili/kratos/tool/kratos-protoc
protoc: 安裝成功!
2019/12/18 15:38:39 您還沒安裝protobuf，請進行手動安裝：https://github.com/protocolbuffers/protobuf/releases
exit status 1
go get -u github.com/bilibili/kratos/tool/kratos-gen-bts
genbts: 安裝成功!
Close: 無聲明 忽略此方法
Ping: 無聲明 忽略此方法
dao.bts.go: 生成成功
go get -u github.com/bilibili/kratos/tool/kratos-gen-mc
genmc: 安裝成功!
mc.cache.go: 生成成功
go get -u github.com/google/wire/cmd/wire
go: finding github.com/google/wire v0.4.0
go: downloading github.com/google/wire v0.4.0
go: extracting github.com/google/wire v0.4.0
go: downloading golang.org/x/tools v0.0.0-20191105231337-689d0f08e67a
go: downloading github.com/google/subcommands v1.0.1
go: extracting github.com/google/subcommands v1.0.1
go: extracting golang.org/x/tools v0.0.0-20191105231337-689d0f08e67a
go: finding golang.org/x/tools latest
go: finding github.com/google/subcommands v1.0.1
go: downloading golang.org/x/tools v0.0.0-20191218040434-6f9e13bbec44
go: extracting golang.org/x/tools v0.0.0-20191218040434-6f9e13bbec44
wire: 安裝成功!
wire: C:\server\src\go\src\demo\internal\di\wire.go:17:65: DemoServer not declared by package api
wire: generate failed
exit status 1
Project: demo
OnlyGRPC: false
OnlyHTTP: false
Directory: C:\server\src\go\src\demo

項目創建成功.

其中提示了沒安裝protobuf，需要手動安裝，先不管他直接跑demo試試。

2019/12/18 15:38:39 您還沒安裝protobuf，請進行手動安裝：https://github.com/protocolbuffers/protobuf/releases

kratos run

C:\server\src\go\src\demo>kratos run
go: downloading github.com/shirou/gopsutil v2.19.6+incompatible
build command-line-arguments: cannot load github.com/shirou/gopsutil/cpu: github.com/shirou/gopsutil@v2.19.6+incompatible: reading https://goproxy.io/github.com/shirou/gopsutil/@v/v2.19.6+incompatible.zip: 410 Gone
panic: exit status 1

goroutine 1 [running]:
main.runAction(0xc0000922c0, 0x0, 0xc000042f30)
        C:/server/src/go/pkg/mod/github.com/bilibili/kratos@v0.3.1/tool/kratos/run.go:25 +0x36e
github.com/urfave/cli.HandleAction(0x603080, 0x65fda8, 0xc0000922c0, 0xc0000922c0, 0x0)
        C:/server/src/go/pkg/mod/github.com/urfave/cli@v1.22.2/app.go:523 +0xc5
github.com/urfave/cli.Command.Run(0x64c994, 0x3, 0x0, 0x0, 0xc000042de0, 0x1, 0x1, 0x650d90, 0xa, 0x0, ...)
        C:/server/src/go/pkg/mod/github.com/urfave/cli@v1.22.2/command.go:174 +0x523
github.com/urfave/cli.(*App).Run(0xc0000ea000, 0xc0000044a0, 0x2, 0x2, 0x0, 0x0)
        C:/server/src/go/pkg/mod/github.com/urfave/cli@v1.22.2/app.go:276 +0x72c
main.main()
        C:/server/src/go/pkg/mod/github.com/bilibili/kratos@v0.3.1/tool/kratos/main.go:57 +0x3f7

報錯:
cannot load github.com/shirou/gopsutil

好像是不能加載gopsutil 包
直接一下個試試：

go get -u github.com/shirou/gopsutil

C:\server\src\go\src\demo>go get -u github.com/shirou/gopsutil
go: downloading github.com/shirou/gopsutil v2.19.11+incompatible
go: extracting github.com/shirou/gopsutil v2.19.11+incompatible

C:\server\src\go\src\demo>kratos run
go: downloading github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6
go: extracting github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6
go: downloading github.com/go-ole/go-ole v1.2.4
go: extracting github.com/go-ole/go-ole v1.2.4
# demo/api
..\api\client.go:15:68: undefined: DemoClient
..\api\client.go:21:9: undefined: NewDemoClient
panic: exit status 2

可以運行了，但是沒跑起來，api路徑貌似和protobuf是有關聯的，那麼安裝個protobuf試試。

https://github.com/protocolbuffers/protobuf/releases

下載，我是windows系統在path裏面添加下bin目錄環境變量即可。

protoc
Usage: protoc [OPTION] PROTO_FILES
Parse PROTO_FILES and generate output based on the options given:
  -IPATH, --proto_path=PATH   Specify the directory in which to search for
                              imports.  May be specified multiple times;
                              directories will be searched in order.  If not
                              given, the current working directory is used.
                              If not found in any of the these directories,
                              the --descriptor_set_in descriptors will be
                              checked for required proto file.
  --version                   Show version info and exit.
  -h, --help                  Show this text and exit.
  --encode=MESSAGE_TYPE       Read a text-format message of the given type
                              from standard input and write it in binary
                              to standard output.  The message type must
                              be defined in PROTO_FILES or their imports.
  --decode=MESSAGE_TYPE       Read a binary message of the given type from
                              standard input and write it in text format
                              to standard output.  The message type must
                              be defined in PROTO_FILES or their imports.
  --decode_raw                Read an arbitrary protocol message from
                              standard input and write the raw tag/value
                              pairs in text format to standard output.  No
                              PROTO_FILES should be given when using this
                              flag.
  --descriptor_set_in=FILES   Specifies a delimited list of FILES
                              each containing a FileDescriptorSet (a
                              protocol buffer defined in descriptor.proto).
                              The FileDescriptor for each of the PROTO_FILES
                              provided will be loaded from these
                              FileDescriptorSets. If a FileDescriptor
                              appears multiple times, the first occurrence
                              will be used.
  -oFILE,                     Writes a FileDescriptorSet (a protocol buffer,
    --descriptor_set_out=FILE defined in descriptor.proto) containing all of
                              the input files to FILE.
  --include_imports           When using --descriptor_set_out, also include
                              all dependencies of the input files in the
                              set, so that the set is self-contained.
  --include_source_info       When using --descriptor_set_out, do not strip
                              SourceCodeInfo from the FileDescriptorProto.
                              This results in vastly larger descriptors that
                              include information about the original
                              location of each decl in the source file as
                              well as surrounding comments.
  --dependency_out=FILE       Write a dependency output file in the format
                              expected by make. This writes the transitive
                              set of input file paths to FILE
  --error_format=FORMAT       Set the format in which to print errors.
                              FORMAT may be 'gcc' (the default) or 'msvs'
                              (Microsoft Visual Studio format).
  --print_free_field_numbers  Print the free field numbers of the messages
                              defined in the given proto files. Groups share
                              the same field number space with the parent
                              message. Extension ranges are counted as
                              occupied fields numbers.

  --plugin=EXECUTABLE         Specifies a plugin executable to use.
                              Normally, protoc searches the PATH for
                              plugins, but you may specify additional
                              executables not in the path using this flag.
                              Additionally, EXECUTABLE may be of the form
                              NAME=PATH, in which case the given plugin name
                              is mapped to the given executable even if
                              the executable's own name differs.
  --cpp_out=OUT_DIR           Generate C++ header and source.
  --csharp_out=OUT_DIR        Generate C# source file.
  --java_out=OUT_DIR          Generate Java source file.
  --js_out=OUT_DIR            Generate JavaScript source.
  --objc_out=OUT_DIR          Generate Objective C header and source.
  --php_out=OUT_DIR           Generate PHP source file.
  --python_out=OUT_DIR        Generate Python source file.
  --ruby_out=OUT_DIR          Generate Ruby source file.
  @<filename>                 Read options and filenames from file. If a
                              relative file path is specified, the file
                              will be searched in the working directory.
                              The --proto_path option will not affect how
                              this argument file is searched. Content of
                              the file will be expanded in the position of
                              @<filename> as in the argument list. Note
                              that shell expansion is not applied to the
                              content of the file (i.e., you cannot use
                              quotes, wildcards, escapes, commands, etc.).
                              Each line corresponds to a single argument,
                              even if it contains spaces.

確保protoc能夠執行，刪除demo目錄重新創建：

這次能夠運行成功了

先試試文檔給的路徑：

不行， 看看源碼:

blademaster應該就是對gin框架的裁剪

看看demo服務做了什麼，

// New new a bm server.
func New(s pb.DemoServer) (engine *bm.Engine, err error) {
	var (
		hc struct {
			Server *bm.ServerConfig
		}
	)
	if err = paladin.Get("http.toml").UnmarshalTOML(&hc); err != nil {
		if err != paladin.ErrNotExist {
			return
		}
		err = nil
	}
	svc = s
	engine = bm.DefaultServer(hc.Server)
	pb.RegisterDemoBMServer(engine, s)
	initRouter(engine)
	err = engine.Start()
	return
}

func initRouter(e *bm.Engine) {
	e.Ping(ping)
	g := e.Group("/abc")
	{
		g.GET("/start", howToStart)
	}
}

添加了個/abc組，註冊了/start 路由.

// Group creates a new router group. You should add all the routes that have common middlwares or the same path prefix.
// For example, all the routes that use a common middlware for authorization could be grouped.
func (group *RouterGroup) Group(relativePath string, handlers ...HandlerFunc) *RouterGroup {
	return &RouterGroup{
		Handlers: group.combineHandlers(handlers),
		basePath: group.calculateAbsolutePath(relativePath),
		engine:   group.engine,
		root:     false,
	}
}

看介紹，大概意思是創建給使用相同中間件和路徑前綴的路由使用的路由組。

試試路徑
/abc/start

成功了：