fix(test): reuse ReadLogFileAndSearchString for auto-port log; throttle poll loop

Signed-off-by: Andrei Aaron <andreifdaaron@gmail.com>

Author: andaaron

pkg/api/controller_test.go

@@ -588,31 +588,17 @@ func TestAutoPortSelection(t *testing.T) {
 
 		defer cm.StopServer()
 
-		scanner := bufio.NewScanner(logFile)
-
-		var contents bytes.Buffer
-
-		deadline := time.Now().Add(30 * time.Second)
-
-		for scanner.Scan() {
-			text := scanner.Text()
-			contents.WriteString(text)
-
-			if strings.Contains(text, "port is unspecified") {
-				break
-			}
-
-			if time.Now().After(deadline) {
-				t.Fatalf("timed out waiting for kernel-chosen port log line")
-			}
-		}
+		found, err := test.ReadLogFileAndSearchString(logFile.Name(), "port is unspecified", 30*time.Second)
+		So(err, ShouldBeNil)
+		So(found, ShouldBeTrue)
 
-		So(scanner.Err(), ShouldBeNil)
-		So(contents.String(), ShouldContainSubstring,
+		contents, err := os.ReadFile(logFile.Name())
+		So(err, ShouldBeNil)
+		So(string(contents), ShouldContainSubstring,
 			"port is unspecified, listening on kernel chosen port",
 		)
-		So(contents.String(), ShouldContainSubstring, "\"address\":\"127.0.0.1\"")
-		So(contents.String(), ShouldContainSubstring, "\"port\":")
+		So(string(contents), ShouldContainSubstring, "\"address\":\"127.0.0.1\"")
+		So(string(contents), ShouldContainSubstring, "\"port\":")
 
 		So(ctlr.GetPort(), ShouldBeGreaterThan, 0)
 		So(ctlr.GetPort(), ShouldBeLessThan, 65536)

pkg/test/common/fs.go

@@ -179,19 +179,29 @@ func ReadLogFileAndSearchString(logPath string, stringToMatch string, timeout ti
 	ctx, cancelFunc := context.WithTimeout(context.Background(), timeout)
 	defer cancelFunc()
 
+	ticker := time.NewTicker(10 * time.Millisecond)
+	defer ticker.Stop()
+
 	for {
 		select {
 		case <-ctx.Done():
 			return false, nil
 		default:
-			content, err := os.ReadFile(logPath)
-			if err != nil {
-				return false, err
-			}
+		}
 
-			if strings.Contains(string(content), stringToMatch) {
-				return true, nil
-			}
+		content, err := os.ReadFile(logPath)
+		if err != nil {
+			return false, err
+		}
+
+		if strings.Contains(string(content), stringToMatch) {
+			return true, nil
+		}
+
+		select {
+		case <-ctx.Done():
+			return false, nil
+		case <-ticker.C:
 		}
 	}
 }
@@ -202,19 +212,29 @@ func ReadLogFileAndCountStringOccurence(logPath string, stringToMatch string,
 	ctx, cancelFunc := context.WithTimeout(context.Background(), timeout)
 	defer cancelFunc()
 
+	ticker := time.NewTicker(10 * time.Millisecond)
+	defer ticker.Stop()
+
 	for {
 		select {
 		case <-ctx.Done():
 			return false, nil
 		default:
-			content, err := os.ReadFile(logPath)
-			if err != nil {
-				return false, err
-			}
+		}
 
-			if strings.Count(string(content), stringToMatch) >= count {
-				return true, nil
-			}
+		content, err := os.ReadFile(logPath)
+		if err != nil {
+			return false, err
+		}
+
+		if strings.Count(string(content), stringToMatch) >= count {
+			return true, nil
+		}
+
+		select {
+		case <-ctx.Done():
+			return false, nil
+		case <-ticker.C:
 		}
 	}
 }

pkg/test/common/fs_test.go

@@ -145,6 +145,25 @@ func TestReadLogFileAndSearchString(t *testing.T) {
 		So(err, ShouldBeNil)
 		So(ok, ShouldBeFalse)
 	})
+
+	Convey("substring appears after append", t, func() {
+		logPath := path.Join(t.TempDir(), "log.txt")
+		So(os.WriteFile(logPath, []byte("header\n"), 0o600), ShouldBeNil)
+
+		go func() {
+			time.Sleep(40 * time.Millisecond)
+			f, err := os.OpenFile(logPath, os.O_APPEND|os.O_WRONLY, 0o600)
+			if err != nil {
+				return
+			}
+			defer f.Close()
+			_, _ = f.WriteString("line with port is unspecified\n")
+		}()
+
+		ok, err := tcommon.ReadLogFileAndSearchString(logPath, "port is unspecified", 500*time.Millisecond)
+		So(err, ShouldBeNil)
+		So(ok, ShouldBeTrue)
+	})
 }
 
 func TestReadLogFileAndCountStringOccurence(t *testing.T) {