feat(gin): Add support for ApiGateway V2 version for the Gin adapter

Author: zoltanarvai

gin/adapterv2.go

@@ -0,0 +1,62 @@
+// Package ginadapterv2 adds Gin support for the aws-severless-go-api library.
+// Uses the core package behind the scenes and exposes the NewV2 method to
+// get a new instance and Proxy method to send request to the Gin engine.
+package ginadapter
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/aws/aws-lambda-go/events"
+	"github.com/awslabs/aws-lambda-go-api-proxy/core"
+	"github.com/gin-gonic/gin"
+)
+
+// GinLambdaV2 makes it easy to send API Gateway proxy V2 events to a Gin
+// Engine. The library transforms the proxy event into an HTTP request and then
+// creates a proxy response object from the http.ResponseWriter
+type GinLambdaV2 struct {
+	core.RequestAccessorV2
+
+	ginEngine *gin.Engine
+}
+
+// NewV2 creates a new instance of the GinLambdaV2 object.
+// Receives an initialized *gin.Engine object - normally created with gin.Default().
+// It returns the initialized instance of the GinLambdaV2 object.
+func NewV2(gin *gin.Engine) *GinLambdaV2 {
+	return &GinLambdaV2{ginEngine: gin}
+}
+
+// Proxy receives an API Gateway proxy V2 event, transforms it into an http.Request
+// object, and sends it to the gin.Engine for routing.
+// It returns an http response object generated from the http.ResponseWriter.
+func (g *GinLambdaV2) Proxy(req events.APIGatewayV2HTTPRequest) (events.APIGatewayV2HTTPResponse, error) {
+	ginRequest, err := g.ProxyEventToHTTPRequest(req)
+	return g.proxyInternal(ginRequest, err)
+}
+
+// ProxyWithContext receives context and an API Gateway proxy V2 event,
+// transforms them into an http.Request object, and sends it to the gin.Engine for routing.
+// It returns an http response object generated from the http.ResponseWriter.
+func (g *GinLambdaV2) ProxyWithContext(ctx context.Context, req events.APIGatewayV2HTTPRequest) (events.APIGatewayV2HTTPResponse, error) {
+	ginRequest, err := g.EventToRequestWithContext(ctx, req)
+	return g.proxyInternal(ginRequest, err)
+}
+
+func (g *GinLambdaV2) proxyInternal(req *http.Request, err error) (events.APIGatewayV2HTTPResponse, error) {
+
+	if err != nil {
+		return core.GatewayTimeoutV2(), core.NewLoggedError("Could not convert proxy event to request: %v", err)
+	}
+
+	respWriter := core.NewProxyResponseWriterV2()
+	g.ginEngine.ServeHTTP(http.ResponseWriter(respWriter), req)
+
+	proxyResponse, err := respWriter.GetProxyResponse()
+	if err != nil {
+		return core.GatewayTimeoutV2(), core.NewLoggedError("Error while generating proxy response: %v", err)
+	}
+
+	return proxyResponse, nil
+}

gin/ginlambda_test.go

@@ -43,3 +43,39 @@ var _ = Describe("GinLambda tests", func() {
 		})
 	})
 })
+
+var _ = Describe("GinLambdaV2 tests", func() {
+	Context("Simple ping request", func() {
+		It("Proxies the event correctly", func() {
+			log.Println("Starting test")
+			r := gin.Default()
+			r.GET("/ping", func(c *gin.Context) {
+				log.Println("Handler!!")
+				c.JSON(200, gin.H{
+					"message": "pong",
+				})
+			})
+
+			adapter := ginadapter.NewV2(r)
+
+			req := events.APIGatewayV2HTTPRequest{
+				RequestContext: events.APIGatewayV2HTTPRequestContext{
+					HTTP: events.APIGatewayV2HTTPRequestContextHTTPDescription{
+						Method: "GET",
+						Path:   "/ping",
+					},
+				},
+			}
+
+			resp, err := adapter.ProxyWithContext(context.Background(), req)
+
+			Expect(err).To(BeNil())
+			Expect(resp.StatusCode).To(Equal(200))
+
+			resp, err = adapter.Proxy(req)
+
+			Expect(err).To(BeNil())
+			Expect(resp.StatusCode).To(Equal(200))
+		})
+	})
+})