[storage emulator] Written 3 bytes but got 5 bytes

[gebv]

[REQUIRED] Environment info

firebase-tools: 9.14.0

Platform: macOS

For use storage emulator in local uses hack from https://github.com/googleapis/google-cloud-go/issues/2476#issuecomment-692044747

[REQUIRED] Test case

package main

import (
	"context"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"

	"cloud.google.com/go/storage"
	"google.golang.org/api/option"
)

type roundTripper url.URL

func (rt roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
	req.Host = rt.Host
	req.URL.Host = rt.Host
	req.URL.Scheme = rt.Scheme
	return http.DefaultTransport.RoundTrip(req)
}

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	u, _ := url.Parse("http://localhost:9199")
	hClient := &http.Client{Transport: roundTripper(*u)}
	cs, err := storage.NewClient(context.Background(), option.WithHTTPClient(hClient))

	if err != nil {
		log.Fatalln("Failed firebase app to storage.", err)
	}

	b := cs.Bucket("default-bucket")

	{
		w := b.Object("f1").NewWriter(ctx)
		dat := "123"
		n, _ := w.Write([]byte(dat))
		log.Printf("Bytes written %q (size %d)\n", dat, n)
		if err := w.Close(); err != nil {
			log.Fatalln("Failed write file.", err)
		}
	}

	{
		r, err := b.Object("f1").NewReader(ctx)
		if err != nil {
			log.Fatalln("Failed open file.", err)
		}
		dat, err := ioutil.ReadAll(r)
		if err != nil {
			log.Fatalln("Failed read file.", err)
		}
		if err := r.Close(); err != nil {
			log.Fatalln("Failed write file.", err)
		}
		log.Printf("Got data %q (size %d)\n", string(dat), r.Size())
	}

}

2021/07/07 15:30:19 Bytes written "123" (size 3)
2021/07/07 15:30:19 Got data "123\r\n" (size 5)

[REQUIRED] Steps to reproduce

$cat firebase.json
{
  "emulators": {
    "storage": {
      "port": 9199
    },
    "ui": {
      "enabled": true,
      "port": 4000
    }
  },
  "storage": {
    "rules": "storage.rules"
  }
}

$ cat storage.rules
rules_version = '2';
service firebase.storage {
  match /b/{bucket}/o {
    match /{allPaths=**} {
      allow read, write: if true;
    }
  }
}

$ firebase emulators:start

$ STORAGE_EMULATOR_HOST=localhost:9199 PROJECT=myproject go run ./main.go

[REQUIRED] Expected behavior

I want got what was send

[REQUIRED] Actual behavior

I get extra 2 bytes of line wrap in content

PS storage emulator not ready for work yet?

[abeisgoat]

Our emulator doesn't currently guarantee compatibility with any Google Cloud SDKs / Firebase Admin SDKs except Node.js, so you're correct that this is a bug, but it's also not something currently have in scope. I'll leave this open because it might be an easy fix, but we currently don't officially support use of the Go SDK with the Cloud Storage for Firebase emulator.

[tonyjhuang]

Filed internal bug to track, b/240637644