Deploying to AWS Lambda with Gin-Gonic

[axelrogg]

Hi there, this is my first time trying to deploy my gqlgen server to... anywhere really, and most of the "recipes" I found in Google involve AWS Lambda, so here I am. Also, because of Google I came across this discussion published here a while back; however, I'm not sure if it translates properly to gin. My attempt is below. Any suggestions are much appreciated. Thanks!

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/99designs/gqlgen/graphql/handler"
	"github.com/99designs/gqlgen/graphql/playground"
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	ginadapter "github.com/awslabs/aws-lambda-go-api-proxy/gin"
	"github.com/gin-gonic/gin"

	"<my-repo>graph"
	"<my-repo>/graph/resolvers"
)

var ginLambda *ginadapter.GinLambdaV2
var ginRouter *gin.Engine
var ginMode string
var port = "8080"

type ContextKey string

func ginContextToContextMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		ctx := context.WithValue(
			c.Request.Context(), ContextKey("GinContextKey"), c,
		)
		c.Request = c.Request.WithContext(ctx)
		c.Next()
	}
}

func graphqlHandler() gin.HandlerFunc {
	h := handler.NewDefaultServer(graph.NewExecutableSchema(graph.Config{Resolvers: &resolvers.Resolver{}}))
	return func(c *gin.Context) {
		h.ServeHTTP(c.Writer, c.Request)
	}
}

func playgroundHandler(path string) gin.HandlerFunc {
	h := playground.Handler("GraphQL", fmt.Sprintf("/%s", path))

	return func(c *gin.Context) {
		h.ServeHTTP(c.Writer, c.Request)
	}
}

func init() {
	ginRouter = gin.Default()
	ginRouter.Use(ginContextToContextMiddleware())
	ginRouter.POST("/query", graphqlHandler())

	ginMode = os.Getenv("GIN_MODE")
	if ginMode != "release" {
		ginRouter.GET("/playground", playgroundHandler("query"))
	}
}

func Handler(ctx context.Context, req events.APIGatewayV2HTTPRequest) (events.APIGatewayV2HTTPResponse, error) {
	// If no name is provided in the HTTP request body, throw an error
	ginLambda = ginadapter.NewV2(ginRouter)
	return ginLambda.ProxyWithContext(ctx, req)
}

func main() {
	if ginMode == "release" {
		lambda.Start(Handler)
	}
	ginRouter.Run(fmt.Sprintf(":%s", port))
}

[axelrogg]

The approach in this repo https://github.com/spachava753/gqlgen-lambda solves the problem