request_with_timeout.go

package main

import (
	"errors"
	"net/http"
	"time"
)

// makeRequest makes simple http request and returns an error channel
func makeRequest() <-chan error {
	// create a buffered error channel
	errChan := make(chan error, 1)

	// initiate a request in a new go routine.
	// this is done so that the request can keep on happening without cancellation
	// in case there is no response from the http call
	// within the designated time.
	go func() {
		resp, err := http.Get("https://medium.com")
		// on receiving the response of http call, we send signal to channel
		// that the response has been received.
		errChan <- err
		defer resp.Body.Close()
	}()

	return errChan
}

func makeRequestWithTimeout(waitTime time.Duration) error {
	timeout := time.After(waitTime * time.Second)
	// wait for either the timeout to happen or getting  the response from makeRequest func
	// return value is defined based on whatever happens first.
	select {
	case <-timeout:
		return errors.New("wait time exceeded, processing will still run in the background")
	case err := <-makeRequest():
		return err
	}
}