当项目逐渐变大之后，服务增多，开发人员增加，单纯的使用go来写服务会遇到风格不统一，开发效率上的问题。

之前研究go的微服务架构go-kit最让人头疼的就是定义服务之后，还要写很多重复的框架代码，一直再想如何使用IDL描述服务，然后自动生成框架代码。

直到遇到老这货 goa，另外一个go的微服务框架。具体介绍看这篇，还有官网。

 

这货实现了框架的代码自动生成（自动生成的代码可以热更新，因为生成代码和自己写的代码是分开的），而且理念也比较时髦，基于API设计，利用插件来扩展业务逻辑。

 

于是想想要赶紧学习玩一下。

 

假定你已经装了golang的环境。

所以，开始下载。

go get github.com/goadesign/goa

go get github.com/goadesign/goa/goagen

go install github.com/goadesign/goa

go install github.com/goadesign/goa/goagen

qingping.zhang@qpzhangmac ~/dev goagen --help

The goagen tool generates artifacts from a goa service design package.

Each command supported by the tool produces a specific type of artifacts. For example

the "app" command generates the code that supports the service controllers.

The "bootstrap" command runs the "app", "main", "client" and "swagger" commands generating the

controllers supporting code and main skeleton code (if not already present) as well as a client

package and tool and the Swagger specification for the API.

Usage:

  goagen [command]

Available Commands:

  app         Generate application code

  main        Generate application scaffolding

  client      Generate client package and tool

  swagger     Generate Swagger

  js          Generate JavaScript client

  schema      Generate JSON Schema

  gen         Run third-party generator

  bootstrap   Equivalent to running the "app", "main", "client" and "swagger" commands.

Flags:

      --debug           enable debug mode, does not cleanup temporary files.

  -d, --design string   design package import path

  -o, --out string      output directory (default "/Users/qingpingzhang/dev")

Use "goagen [command] --help" for more information about a command.

go get gopkg.in/yaml.v2

//design.go

package design                                     // The convention consists of naming the design

                                                   // package "design"

import (

        . "github.com/goadesign/goa/design"        // Use . imports to enable the DSL

        . "github.com/goadesign/goa/design/apidsl"

)

var _ = API("cellar", func() {                     // API defines the microservice endpoint and

        Title("The virtual wine cellar")           // other global properties. There should be one

        Description("A simple goa service")        // and exactly one API definition appearing in

        Scheme("http")                             // the design.

        Host("localhost:8080")

})

var _ = Resource("bottle", func() {                // Resources group related API endpoints

        BasePath("/bottles")                       // together. They map to REST resources for REST

        DefaultMedia(BottleMedia)                  // services.

        Action("show", func() {                    // Actions define a single API endpoint together

                Description("Get bottle by id")    // with its path, parameters (both path

                Routing(GET("/:bottleID"))         // parameters and querystring values) and payload

                Params(func() {                    // (shape of the request body).

                        Param("bottleID", Integer, "Bottle ID")

                })

                Response(OK)                       // Responses define the shape and status code

                Response(NotFound)                 // of HTTP responses.

        })

})

// BottleMedia defines the media type used to render bottles.

var BottleMedia = MediaType("application/vnd.goa.example.bottle+json", func() {

        Description("A bottle of wine")

        Attributes(func() {                         // Attributes define the media type shape.

                Attribute("id", Integer, "Unique bottle ID")

                Attribute("href", String, "API href for making requests on the bottle")

                Attribute("name", String, "Name of wine")

                Required("id", "href", "name")

        })

        View("default", func() {                    // View defines a rendering of the media type.

                Attribute("id")                     // Media types may have multiple views and must

                Attribute("href")                   // have a "default" view.

                Attribute("name")

        })

})

 qingping.zhang@qpzhangmac ~/gocode/src/goa.demo/  goagen bootstrap -d goa.demo/design

app

app/contexts.go

app/controllers.go

app/hrefs.go

app/media_types.go

app/user_types.go

app/test

app/test/bottle.go

main.go

bottle.go

client

client/cellar-cli

client/cellar-cli/main.go

client/cellar-cli/commands.go

client/client.go

client/bottle.go

client/datatypes.go

swagger

swagger/swagger.json

swagger/swagger.yaml

 qingping.zhang@qpzhangmac ~/gocode/src/goa.demo go build

 qingping.zhang@qpzhangmac ~/gocode/src/goa.demo ./goa.demo
2016/05/26 15:45:09 [INFO] mount ctrl=Bottle action=Show route=GET /bottles/:bottleID

2016/05/26 15:45:09 [INFO] listen transport=http addr=:8080

2016/05/26 15:46:21 [INFO] started req_id=qAWO65SPCG-1 GET=/bottles/1 from=127.0.0.1 ctrl=BottleController action=Show

2016/05/26 15:46:21 [INFO] params req_id=qAWO65SPCG-1 bottleID=1

 qingping.zhang@qpzhangmac  ~  curl -i localhost:8080/bottles/1

HTTP/1.1 200 OK

Content-Type: application/vnd.goa.example.bottle

Date: Thu, 26 May 2016 07:07:40 GMT

Content-Length: 29

{"href":"","id":0,"name":""}