How do I use the request decoder to access values of the HTTP Request that are not in the header nor the body?

[ayx-orion]

I'm trying to access some values in the HTTP request header (specifically the value of "remoteIP" )

i've created an Input struct that the request decoder is populating but i couldn't find any examples of getting values that aren't in the path, param, queryString, json body, etc.

my http request looks like this (from server log, doesn't show json payload values)

httpRequest=
{
  "header": {
    "accept":"*/*",
    "accept-encoding": "gzip, deflate, br",
    "connection":"keep-alive",
    "content-length":"280",
    "content-type":"application/json",
    "postman-token":"019a95a5-9a0c-4e14-8b4e-1e529957f668",
    "user-agent":"PostmanRuntime/7.29.0"
  },
  "proto":"HTTP/1.1",
  "remoteIP":"172.20.176.1:56912",
  "requestID":"orion-hyper-vm/5LgNIbnAgS-000001",
  "requestMethod":"POST",
  "requestPath":"/api/v1/archives/verification",
  "requestURL":"http://172.20.176.126:31337/api/v1/archives/verification",
  "scheme":"http"
}

as you can see, the remoteIP (along with some other values) is not part of the headers dictionary, but is still part of the HTTP request itself. how can i access those values?

this is my struct that i'm using for the usecase Input:

type VerificationRequest struct {
	ContentType    string `header:"content-type"`   // this works, is correctly initiated with the value "application/json"
	XForwardedHost string `header:"remoteIP"`   // <-- this doesn't work, kind of expected, but not sure what else to do here :( 
	EntityId       string `json:"entityId" pattern:"^[0-7][0-9A-HJKMNP-TV-Z]{25}$"`
	Uri            string `json:"uri"`
	CallbackUri    string `json:"callbackUri"`
}

EDIT: I think the value of "remoteIP" in that request should correspond to the struct member http.Request.RemoteAddr

[vearutop]

Currently, the easiest way to access remote addr is to embed request.EmbeddedSetter and then get direct access to *http.Request.

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"

	"github.com/swaggest/openapi-go/openapi31"
	"github.com/swaggest/rest/request"
	"github.com/swaggest/rest/web"
	swgui "github.com/swaggest/swgui/v5cdn"
	"github.com/swaggest/usecase"
)

func main() {
	s := web.NewService(openapi31.NewReflector())

	type inputWithReq struct {
		request.EmbeddedSetter

		Locale string `query:"locale" default:"en-US" pattern:"^[a-z]{2}-[A-Z]{2}$" enum:"ru-RU,en-US"`
		Name   string `path:"name" minLength:"3" default:"Jane"`
	}

	u := usecase.NewInteractor(func(ctx context.Context, input inputWithReq, output *struct{}) error {
		fmt.Println("Remote addr:", input.Request().RemoteAddr) // <------------------- *http.Request access

		return nil
	})

	s.Get("/hello/{name}", u)

	s.Docs("/docs", swgui.New)
	log.Println("http://localhost:8011/docs")
	if err := http.ListenAndServe("localhost:8011", s); err != nil {
		log.Fatal(err)
	}
}

Perhaps, we can introduce some field tag to implement automated mapping of remote addr (and maybe some other fields) into structure fields.

[ayx-orion]

Thanks a lot @vearutop, I'll give that a try.

I put down a TODO to implement my own LoadFromHTTPRequest method for the InputStruct I was using but I think this will be much easier and quicker

[ayx-orion]

using the embedded request was super easy and "just worked". Thank you again @vearutop