gin-gonic

gin-gonic 是一個 golang 的 HTTP web framework，使用 framework 可以簡化程式碼，因為很多東西 framework 都幫忙整合做掉了．
先使用 go get 下載 gin-gonic

go get github.com/gin-gonic/gin

Hello Name

使用 gin-gonic 跑一個簡單的範例，url 如果 match /hello/Daniel 會回傳一個 json 格式的資料．

package main

import (
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()
	r.GET("/hello/:name", func(c *gin.Context) {
		name := c.Param("name")
		c.JSON(200, gin.H{
			"message": "hello " + name,
		})
	})
	r.Run()
}

執行 example.go，會啟動一個預設為 8080 的 port，console 會印出綁定的 GET 的 handler．
之後接收到 request 時也會印出 log．

go run example.go
[GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.

[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
 - using env:   export GIN_MODE=release
 - using code:  gin.SetMode(gin.ReleaseMode)

[GIN-debug] GET    /hello/:name              --> main.main.func1 (3 handlers)
[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default[GIN-debug] Listening and serving HTTP on :8080
[GIN] 2018/10/22 - 11:58:39 | 200 |      17.721µs |             ::1 | GET      /hello/Daniel

輸出結果

> curl http://localhost:8080/hello/Daniel
{"message":"hello Daniel"}

路徑 : 與 * 的差異

net/http 裡面定義了很多 http status 的 type 可以直接使用．這次在前面的範例再加上 *action 並透過 c.Param 來取得 action 的值

package main
package main

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()
	r.GET("/hello/:name/*action", func(c *gin.Context) {
		name := c.Param("name")
		action := c.Param("action")

		c.JSON(http.StatusOK, gin.H{
			"name":   name,
			"action": action,
		})
	})
	r.Run(":8081")
}

輸出結果

> curl http://localhost:8081/hello/Daniel/play
{"action":"/play","name":"Daniel"}

: 跟 * 的差異在於，: 如果沒給參數的話會 404，* 可以不給沒關係．

> curl http://localhost:8081/hello/Daniel/
{"action":"/","name":"Daniel"}

> curl http://localhost:8081/hello/
404 page not found

取得 request 參數

使用 Query 與 DefaultQuery 來取得 request 參數．
DefaultQuery 的話如果沒有 firstname 這參數，就會給預設值第二個參數(None)．

package main

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()
	r.GET("/hello/:name/*action", func(c *gin.Context) {
		name := c.Param("name")
		action := c.Param("action")

		firstname := c.DefaultQuery("firstname", "None")
		lastname := c.Query("lastname")

		c.JSON(http.StatusOK, gin.H{
			"name":      name,
			"action":    action,
			"firstname": firstname,
			"lastname":  lastname,
		})
	})
	r.Run(":8081")
}

輸出結果

> curl http://localhost:8081/hello/Daniel/play\?firstnam=Sam\&lastname=Lucas
{"action":"/play","firstname":"None","lastname":"Lucas","name":"Daniel"}

使用 BasicAuth 做認證

使用 BasicAuth 認證並給他 Accounts 參數就是使用者的帳密，
所以只有 Daniel 與 Sam 可以對 "/hello/:name/*action" 做呼叫

package main

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()

	authorized := r.Group("/", gin.BasicAuth(gin.Accounts{
		"Daniel": "123456",
		"Sam":    "abc123",
	}))

	authorized.GET("/hello/:name/*action", func(c *gin.Context) {
		name := c.Param("name")
		action := c.Param("action")

		firstname := c.DefaultQuery("firstname", "None")
		lastname := c.Query("lastname")

		c.JSON(http.StatusOK, gin.H{
			"name":      name,
			"action":    action,
			"firstname": firstname,
			"lastname":  lastname,
		})
	})
	r.Run(":8081")
}

如果沒給帳密的話會什麼都沒有

> curl http://localhost:8081/hello/Daniel/play\?firstnam=Sam\&lastname=Lucas

使用 curl 給帳密的方式測試，有下列 3 種 :

> curl Daniel:123456@localhost:8081/hello/Daniel/play\?firstnam=Sam\&lastname=Lucas
{"action":"/play","firstname":"None","lastname":"Lucas","name":"Daniel"}

> curl -u Sam localhost:8081/hello/Daniel/play\?firstnam=Sam\&lastname=Lucas
Enter host password for user 'Sam':
{"action":"/play","firstname":"None","lastname":"Lucas","name":"Daniel"}%

curl -u Sam:abc123 localhost:8081/hello/Daniel/play\?firstnam=Sam\&lastname=Lucas
{"action":"/play","firstname":"None","lastname":"Lucas","name":"Daniel"}

參考資料
gin-gonic