Add method to check for zero-speed downloads

pkg/client/client.go

@@ -1,11 +1,13 @@
 package client
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"os"
+	"time"
 )
 
 // bufferSize is the size of the buffer for disk I/O.
@@ -70,3 +72,63 @@ func GetFileWithLogin(url, user, pass, destination string) error {
 
 	return nil
 }
+
+// GetFileWithAuthAndTimeout downloads a file from URL to destination using basic auth.
+// It will check if the connection dropped to 0 bytes during the timeout and, in that case, cancels the download.
+func GetFileWithAuthAndTimeout(url, user, pass, path string, timeout time.Duration) error {
+	ctx, cancel := context.WithCancel(context.Background())
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil) // Will be added in Go 1.13
+	if err != nil {
+		return fmt.Errorf("error creating request: %s", err)
+	}
+	req.SetBasicAuth(user, pass)
+
+	f, err := os.Create(path)
+	if err != nil {
+		return fmt.Errorf("error creating file in path \"%s\": %s", path, err)
+	}
+	defer f.Close()
+
+	go checkFileSizeChanging(path, timeout, cancel)
+
+	resp, err := HttpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("download request failed: %s", err)
+	}
+	defer resp.Body.Close()
+
+	if _, err = io.CopyBuffer(f, resp.Body, make([]byte, bufferSize)); err != nil {
+		// If failed, force close and try to remove it
+		_ = f.Close()
+		_ = os.Remove(path)
+		return fmt.Errorf("error while saving file in path \"%s\": %s", path, err)
+	}
+
+	if err = f.Close(); err != nil {
+		return fmt.Errorf("error found closing file in path \"%s\": %s", path, err)
+	}
+
+	return nil
+}
+
+// checkFileSizeChanging will check if the size of the file from the path provided have changed every timeout duration,
+// if it haven't, it calls cancel() and exits.
+func checkFileSizeChanging(path string, timeout time.Duration, cancel func()) {
+	var size int64 = -1
+
+	for {
+		stat, err := os.Stat(path)
+		if err != nil {
+			cancel()
+			return
+		}
+
+		if stat.Size() == size {
+			cancel()
+			return
+		}
+
+		size = stat.Size()
+		time.Sleep(timeout)
+	}
+}