Gqlgen: A recipe for Gin integration?

[frederikhors]

A recipe for Gin integration?

[sandeepone]

IMO you don't need another framework for running the Graphql server. It's always better to use net/http.

[gissleh]

I don't use Gin, but I took a quick look at it. It appears that you can get a *http.Request and http.ResponseWriter from the gin.Context. Have you tried calling the graphql handler's ServerHTTP with those?

[vektah]

I don't use gin, contributions welcome though :)

[rohmanhm]

There is go-chi implementation for cors, maybe you can get something there.

Ref:

• https://gqlgen.com/recipes/cors/

[frederikhors]

@sandeepone

IMO you don't need another framework for running the Graphql server. It's always better to use net/http.

Thanks for your opinion, this is an old battle. I need gin for many reasons.

@gissleh

I don't use Gin, but I took a quick look at it. It appears that you can get a *http.Request and http.ResponseWriter from the gin.Context. Have you tried calling the graphql handler's ServerHTTP with those?

Maybe like the code below?

package server

import (
    "myProject/graphql"
    "github.com/99designs/gqlgen/handler"
    "github.com/gin-gonic/gin"
)

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

    r.GET("/query", gin.WrapH(handler.Playground("GraphQL playground", "/api")))
    r.GET("/api", gin.WrapH(handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}}))))
    r.POST("/api", gin.WrapH(handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}}))))

    r.Run()
}

@vektah can I ask if you see something wrong in the above code? Is it correct to repeat two times these lines?

r.GET("/api", gin.WrapH(handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}}))))
r.POST("/api", gin.WrapH(handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}}))))

(I opened https://github.com/99designs/gqlgen/issues/418 for this problem).

[vektah]

I would just create the handler once and mount it twice, so the caches are shared.

gql := handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}})
r.GET("/api", gin.WrapH(gql))
r.POST("/api", gin.WrapH(gql)))

[frederikhors]

@vektah what do you think?

It's the same if I use this code:

gql := gin.WrapH(handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}})))

r.GET("/api", gql)
r.POST("/api", gql)

instead of this one:

gql := handler.GraphQL(graphql.NewExecutableSchema(graphql.Config{Resolvers: &graphql.Resolver{}})
r.GET("/api", gin.WrapH(gql))
r.POST("/api", gin.WrapH(gql)))

_Differences_: in the first I'm reusing also gin.WrapH.

What about performance? Negligible?

[appleboy]

https://github.com/appleboy/golang-graphql-benchmark/blob/52716c04e3777b66a329280ef1856740187d949d/golang/gqlgen/server/server.go#L1-L28

package main

import (
    "fmt"

    "github.com/99designs/gqlgen/handler"
    "github.com/appleboy/golang-graphql-benchmark/golang/gqlgen"
    "github.com/gin-gonic/gin"
)

// Handler initializes the graphql middleware.
func Handler() gin.HandlerFunc {
    // Creates a GraphQL-go HTTP handler with the defined schema
    h := handler.GraphQL(gqlgen.NewExecutableSchema(gqlgen.Config{Resolvers: &gqlgen.Resolver{}}))

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

func main() {
    r := gin.New()
    r.POST("/graphql", Handler())

    fmt.Println("Now server is running on port 8080")
    fmt.Println("Test with Get      : curl -g 'http://localhost:8080/graphql?query={hello}'")
    r.Run()
}

[huoshiqiu]

Is there any method to use middleware by gin.Context ?

[jonatasbaldin]

Hey @huoshiqiu, added this at #676, what do you think?