ghttp middleware tracing need ungzip response when header contains gzip

[ltp217]

1. What version of Go and system type/arch are you using?

go 1.19, linux/amd64

2. What version of GoFrame are you using?

goframe version v2.2.2

3. Can this issue be re-produced with the latest release?

yes, can re-produced in the latest release, v2.5.0

4. What did you do?

when use goframe server, handle the /metrics to send trace infomation to the otel-collector, it will change to grpc protocol，but will get 'invalid utf-8' error.
the reason is that, when handle to '/metrics', if not set DisableCompress to true, and the header in the request contains 'Account-Encoding: gzip', the response will be gziped. you can see the code in :
https://github.com/prometheus/client_golang/blob/main/prometheus/promhttp/http.go#L172.
And in goframe server middleware, it will set the attribute "http.response.body" with the value of response, but now the response is now gziped, it will not be valid utf-8 string.
So when send traces by grpc in https://github.com/protocolbuffers/protobuf-go/blob/master/internal/impl/codec_gen.go#L5028, it will return "invalid utf-8" error.


prometheus server like this:

func New(ctx context.Context, opts ...Opt) *ghttp.Server {
	config, err := initConfig(ctx, opts...)
	if err != nil {
		log.New().Fatalf(ctx, "init config fail, err:%+v", err)
	}
	s := g.Server(defaultServerName)
	s.SetAddr(config.Address)
	s.SetDumpRouterMap(false)
	// metrics采集不需要swagger接口
	s.SetSwaggerPath("")
	s.SetOpenApiPath("")
	s.BindHandler("/metrics", func(r *ghttp.Request) {
		promhttp.InstrumentMetricHandler(
			prometheus.DefaultRegisterer,
			promhttp.HandlerFor(prometheus.DefaultGatherer,
				promhttp.HandlerOpts{})).ServeHTTP(r.Response.Writer, r.Request)
	})
	return s
}

before the promhttp.HandlerOpts don't contains 'DisableCompression: true'
and use the otel by grpc protocol, can see:https://github.com/open-telemetry/opentelemetry-go/tree/main/example/otel-collector.

5. What did you expect to see?

maybe in goframe, when add attribute in the server middleware, need to check the header contains 'gzip' or not , if contains, the response should be ungzip, and then set the ungziped string to the attribute.

[github-actions]

Hello @ltp217. We like your proposal/feedback and would appreciate a contribution via a Pull Request by you or another community member. We thank you in advance for your contribution and are looking forward to reviewing it!
你好 @ltp217。我们喜欢您的提案/反馈，并希望您或其他社区成员通过拉取请求做出贡献。我们提前感谢您的贡献，并期待对其进行审查。