Endpoint not found using Gin

[garrettlove8]

Followed the instructions to a T and using this code (from the example):

var ginLambda *ginadapter.GinLambda

func init() {
    // stdout and stderr are sent to AWS CloudWatch Logs
    log.Printf("Gin cold start")
    r := gin.Default()
    r.GET("/ping", func(c *gin.Context) {
        fmt.Println("ping route")
        c.JSON(200, gin.H{
            "message": "pong",
        })
    })

    ginLambda = ginadapter.New(r)
}

func Handler(ctx context.Context, req events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
    // If no name is provided in the HTTP request body, throw an error
    return ginLambda.ProxyWithContext(ctx, req)
}

func main() {
    fmt.Println("Starting Lambda request")
    lambda.Start(Handler)
}

However, getting a 404 returned when I hit this route:

{
  "message": "Not Found"
}

[ashleycheung]

It worked for me when I used version 2 instead of the default one

var ginLambda *ginadapter.GinLambdaV2

func init() {
    // stdout and stderr are sent to AWS CloudWatch Logs
    log.Printf("Gin cold start")
    r := gin.Default()
    r.GET("/ping", func(c *gin.Context) {
        c.JSON(200, gin.H{
            "message": "pong",
        })
    })

    ginLambda = ginadapter.NewV2(r)
}

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

func main() {
    lambda.Start(Handler)
}

[lucianthorr]

I think I'm in a similar boat, trying to get a gin-gonic to work in Lambda. @ashleycheung, using your snippet, I get a 200, "Healthy Connection" response but I don't actually get the "pong" message response. Do you? If so, would you mind sharing how your API Gateway is configured? I can get the httpadapter to work but I'm having no luck with Gin for some reason. Thanks

[tschaffter]

@lucianthorr The /ping path is reserved by the AWS API Gateway (see API Gateway known issues).

Example:

$ curl -i -X GET https://xxx.execute-api.us-east-1.amazonaws.com/ping
HTTP/2 200 
date: Sat, 22 Oct 2022 22:40:45 GMT
content-length: 18

Healthy Connection

$ curl -i -X GET https://xxx.execute-api.us-east-1.amazonaws.com/ping2
HTTP/2 200 
date: Sat, 22 Oct 2022 22:51:00 GMT
content-type: application/json; charset=utf-8
content-length: 13
x-powered-by: Express
etag: W/"d-NMovXDE1NuzTr1lpmBE8ZRjliFM"
apigw-requestid: abcI6gsZIAMESMA=

{"pong":true}

[noce2]

@lucianthorr were you able to get an answer? @ashleycheung wouod you be able to share how yours is configured? Getting the same issue too.

[noce2]

Found the issue on this, it's the payload version. It turns out if it's not specified when creating an ApiGatewayV2 integration in [Terraform] (https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/apigatewayv2_integration#payload_format_version) the payload version is assumed to be 1.0. This is possibly also the behaviour in Cloudformation. The GinLambdaV2 was expecting and v2 payload but failed on received the default set v1 payload. Hope this helps someone else.

[lucianthorr]

@noce2 That's great. Although it's too long ago for me to recall 100%, I believe I ended up moving over to AWS App Runner because a lot of the Api Gateway stuff is setup automatically as part of the service and from there, you don't need GinLambda to run a gin server.

[foliveiracamara]

@ashleycheung This worked as well for me using echoadapter.EchoLambdaV2, thanks for your answer, been struggling for 2 days.

[dsncode]

a small snippet that worked for me by using echoadapter.EchoLambdaV2. I hope it helps someone else as well

package main

import (
    "context"
    "net/http"
    "time"

    "github.com/aws/aws-lambda-go/events"
    "github.com/aws/aws-lambda-go/lambda"
    echoadapter "github.com/awslabs/aws-lambda-go-api-proxy/echo"
    "github.com/labstack/echo/v4"
)

type Response struct {
    From    string
    Message string
}

var echoLambda *echoadapter.EchoLambdaV2

func init() {
    e := echo.New()
    e.GET("/", func(c echo.Context) error {
        return c.JSON(http.StatusOK, Response{From: "/", Message: time.Now().Format(time.UnixDate)})
    })

    e.GET("/ping", func(c echo.Context) error {
        return c.JSON(http.StatusOK, Response{From: "/ping", Message: time.Now().Format(time.UnixDate)})
    })

    echoLambda = echoadapter.NewV2(e)
}

func Handler(ctx context.Context, req events.APIGatewayV2HTTPRequest) (events.APIGatewayV2HTTPResponse, error) {
    return echoLambda.ProxyWithContext(ctx, req)
}

func main() {
    lambda.Start(Handler)
}