feat: make curl progress bar correctly shows on the gui

package/harvester-os/files/usr/sbin/harv-install

@@ -104,7 +104,21 @@ get_url()
             attempts=5
             until [ "$n" -ge "$attempts" ]
             do
-                curl -o $TO -fL ${FROM} && break
+                # Because `curl` command uses `\r` to overwrite the progress bar,
+                # so we should also consider `\r` when splitting the output.
+                # Hence, we use `startcurl` and `endcurl` to trigger replacing the progress bar.
+                # But, when we use `\r` to display, the header will be overwritten, so we need to print the header manually.
+                echo "% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current"
+                echo "                               Dload  Upload   Total   Spent    Left  Speed"
+                echo "startcurl"
+                curl -o $TO -fL ${FROM} 2>&1
+                curl_result=$?
+                echo "endcurl"
+
+                if [ "$curl_result" -eq 0  ]; then
+                    break
+                fi
+
                 n=$((n+1))
                 echo "Failed to download, retry attempt ${n} out of ${attempts}"
                 sleep 2

pkg/console/util.go

@@ -2,6 +2,7 @@ package console
 
 import (
 	"bufio"
+	"bytes"
 	"context"
 	"crypto/tls"
 	"encoding/binary"
@@ -396,12 +397,59 @@ func execute(ctx context.Context, g *gocui.Gui, env []string, cmdName string) er
 	return cmd.Wait()
 }
 
+func dropCR(data []byte) []byte {
+	if len(data) > 0 && data[len(data)-1] == '\r' {
+		return data[0 : len(data)-1]
+	}
+	return data
+}
+
+func ScanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	if atEOF && len(data) == 0 {
+		return 0, nil, nil
+	}
+
+	if i := bytes.IndexByte(data, '\n'); i >= 0 {
+		// We have a full newline-terminated line.
+		return i + 1, dropCR(data[0:i]), nil
+	}
+
+	if i := bytes.IndexByte(data, '\r'); i >= 0 {
+		// We have a full newline-terminated line.
+		return i + 1, dropCR(data[0:i]), nil
+	}
+
+	// If we're at EOF, we have a final, non-terminated line. Return it.
+	if atEOF {
+		return len(data), dropCR(data), nil
+	}
+	// Request more data.
+	return 0, nil, nil
+}
+
 func printToPanelAndLog(g *gocui.Gui, panel string, logPrefix string, reader io.Reader, lock *sync.Mutex) {
 	scanner := bufio.NewScanner(reader)
+	scanner.Split(ScanLines)
+	currentPrinter := printToPanel
+
 	for scanner.Scan() {
 		logrus.Infof("%s: %s", logPrefix, scanner.Text())
 		lock.Lock()
-		printToPanel(g, scanner.Text(), panel)
+		text := scanner.Text()
+
+		if strings.Contains(text, "startcurl") {
+			currentPrinter = printCurlProgressBarToPanel
+			lock.Unlock()
+			continue
+		}
+		if strings.Contains(text, "endcurl") {
+			currentPrinter = printToPanel
+			printToPanel(g, " ", panel)
+			lock.Unlock()
+			continue
+		}
+
+		currentPrinter(g, text, panel)
 		lock.Unlock()
 	}
 }
@@ -581,12 +629,10 @@ func doUpgrade(g *gocui.Gui) error {
 	}
 
 	scanner := bufio.NewScanner(stdout)
-	scanner.Split(bufio.ScanLines)
 	for scanner.Scan() {
 		printToPanel(g, scanner.Text(), upgradePanel)
 	}
 	scanner = bufio.NewScanner(stderr)
-	scanner.Split(bufio.ScanLines)
 	for scanner.Scan() {
 		printToPanel(g, scanner.Text(), upgradePanel)
 	}
@@ -615,6 +661,28 @@ func printToPanel(g *gocui.Gui, message string, panelName string) {
 	<-ch
 }
 
+func printCurlProgressBarToPanel(g *gocui.Gui, message string, panelName string) {
+	// block printToPanel call in the same goroutine.
+	// This ensures messages are printed out in the calling order.
+	ch := make(chan struct{})
+
+	g.Update(func(g *gocui.Gui) error {
+
+		defer func() {
+			ch <- struct{}{}
+		}()
+
+		v, err := g.View(panelName)
+		if err != nil {
+			return err
+		}
+		v.Write(append([]byte{'\r'}, []byte(message)...))
+		return nil
+	})
+
+	<-ch
+}
+
 func getRemoteConfig(configURL string) (*config.HarvesterConfig, error) {
 	client := newProxyClient()
 	b, err := getURL(client, configURL)