gin-gonic/gin

Create gin-gonic/gin server with rk-boot and rk-gin plugins.

Overview#

We will use rk-boot start gin-gonic/gin microservice and add /v1/greeter API into it.

Furthermore, we will enable bellow functionalities.

Functionality	Description
Swagger UI	Enable Swagger UI
API Docs UI	Enable RapiDoc UI
Prometheus Client	Enable Prometheus Client
Logging middleware	Automatically record logs for every API calls
Prometheus middleware	Automatically record prometheus metrics for every API calls
Meta middleware	Automatically add requestID for every API response

Install#

go get github.com/rookie-ninja/rk-boot/v2
go get github.com/rookie-ninja/rk-gin/v2

1. Create boot.yaml#

gin:
  - name: greeter
    port: 8080
    enabled: true
    sw:
      enabled: true               # Enable Swagger UI，default path: /sw
    docs:
      enabled: true               # Enable API Doc UI，default path: /docs
    prom:
      enabled: true               # Enable Prometheus Client，default path: /metrics
    middleware:
      logging:
        enabled: true
      prom:
        enabled: true
      meta:
        enabled: true

2. Create main.go#

In order to generate swagger.json file, we add comments and generate swagger.json file with swag CLI.

package main

import (
    "context"
    "fmt"
    "github.com/gin-gonic/gin"
    "github.com/rookie-ninja/rk-boot/v2"
    "github.com/rookie-ninja/rk-gin/v2/boot"
    "net/http"
)

// @title Swagger Example API
// @version 1.0
// @description This is a sample rk-demo server.
// @termsOfService http://swagger.io/terms/

// @securityDefinitions.basic BasicAuth

// @contact.name API Support
// @contact.url http://www.swagger.io/support
// @contact.email support@swagger.io

// @license.name Apache 2.0
// @license.url http://www.apache.org/licenses/LICENSE-2.0.html
func main() {
    boot := rkboot.NewBoot()

    // Register API
    entry := rkgin.GetGinEntry("greeter")
    entry.Router.GET("/v1/greeter", Greeter)

    boot.Bootstrap(context.TODO())

    boot.WaitForShutdownSig(context.TODO())
}

// Greeter handler
// @Summary Greeter
// @Id 1
// @Tags Hello
// @version 1.0
// @Param name query string true "name"
// @produce application/json
// @Success 200 {object} GreeterResponse
// @Router /v1/greeter [get]
func Greeter(ctx *gin.Context) {
    ctx.JSON(http.StatusOK, &GreeterResponse{
        Message: fmt.Sprintf("Hello %s!", ctx.Query("name")),
    })
}

type GreeterResponse struct {
    Message string
}

3.Generate swagger.json#

$ swag init

4.Directory hierarchy#

$ tree
.
├── boot.yaml
├── docs
│   ├── swagger.json
│   └── swagger.yaml
├── go.mod
├── go.sum
└── main.go

5.Run main.go#

$ go run main.go
2022-04-14T01:09:52.073+0800    INFO    boot/gin_entry.go:656   Bootstrap GinEntry      {"eventId": "432fcdfb-05e8-46a4-b7b2-d6b6967eba88", "entryName": "greeter", "entryType": "GinEntry"}
2022-04-14T01:09:52.074+0800    INFO    boot/gin_entry.go:413   SwaggerEntry: http://localhost:8080/sw/
2022-04-14T01:09:52.074+0800    INFO    boot/gin_entry.go:416   DocsEntry: http://localhost:8080/docs/
2022-04-14T01:09:52.074+0800    INFO    boot/gin_entry.go:419   PromEntry: http://localhost:8080/metrics
------------------------------------------------------------------------
endTime=2022-04-14T01:09:52.074233+08:00
startTime=2022-04-14T01:09:52.073337+08:00
elapsedNano=896392
timezone=CST
ids={"eventId":"432fcdfb-05e8-46a4-b7b2-d6b6967eba88"}
app={"appName":"rk","appVersion":"local","entryName":"greeter","entryType":"GinEntry"}
env={"arch":"amd64","domain":"*","hostname":"lark.local","localIP":"192.168.101.5","os":"darwin"}
payloads={"docsEnabled":true,"docsPath":"/docs/","ginPort":8080,"promEnabled":true,"promPath":"/metrics","promPort":8080,"swEnabled":true,"swPath":"/sw/"}
counters={}
pairs={}
timing={}
remoteAddr=localhost
operation=Bootstrap
resCode=OK
eventStatus=Ended
EOE

6.Validate#

6.4 Send request#

$ curl -vs "localhost:8080/v1/greeter?name=rk-dev"
* ...
< X-Request-Id: 7120529c-893b-4caa-a425-bc268de5cbc0
< X-Rk-App-Domain: *
< X-Rk-App-Name: rk
< X-Rk-App-Unix-Time: 2022-04-14T01:18:39.013447+08:00
< X-Rk-App-Version: local
< X-Rk-Received-Time: 2022-04-14T01:18:39.013447+08:00
< ...
{"Message":"Hello rk-dev!"}

6.5 API Log#

rk-boot will use bellow format of logging. JSON is also supported, please see user guide for details.

------------------------------------------------------------------------
endTime=2022-04-14T01:18:39.013794+08:00
startTime=2022-04-14T01:18:39.013433+08:00
elapsedNano=360521
timezone=CST
ids={"eventId":"7120529c-893b-4caa-a425-bc268de5cbc0","requestId":"7120529c-893b-4caa-a425-bc268de5cbc0"}
app={"appName":"rk","appVersion":"local","entryName":"greeter","entryType":"GinEntry"}
env={"arch":"amd64","domain":"*","hostname":"lark.local","localIP":"192.168.101.5","os":"darwin"}
payloads={"apiMethod":"GET","apiPath":"/v1/greeter","apiProtocol":"HTTP/1.1","apiQuery":"name=rk-dev","userAgent":"curl/7.64.1"}
counters={}
pairs={}
timing={}
remoteAddr=localhost:53333
operation=/v1/greeter
resCode=200
eventStatus=Ended
EOE

6.6 Prometheus Metrics#

Access http://localhost:8080/metrics