Add tests for rotated files in bundle

client/internal/debug/debug.go

@@ -1048,23 +1048,13 @@ func (g *BundleGenerator) addRotatedLogFiles(logDir string) {
 	}
 
 	// This regex will match both logs rotated by us and logrotate on linux
-	pattern := filepath.Join(logDir, "client*.log*.gz")
+	pattern := filepath.Join(logDir, "client*.log.*")
 	files, err := filepath.Glob(pattern)
 	if err != nil {
 		log.Warnf("failed to glob rotated logs: %v", err)
 		return
 	}
 
-	// This regex will match plain logs rotated by logrotate on linux.
-	// We assume that logrotate is configured with nocompress or delaycompress.
-	pattern = filepath.Join(logDir, "client*.log.*")
-	uncompressedFiles, err := filepath.Glob(pattern)
-	if err != nil {
-		log.Warnf("failed to glob rotated logs: %v", err)
-		return
-	}
-	files = uncompressedFiles
-
 	if len(files) == 0 {
 		return
 	}

client/internal/debug/debug_logfiles_test.go

@@ -0,0 +1,103 @@
+package debug
+
+import (
+	"archive/zip"
+	"bytes"
+	"compress/gzip"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestAddRotatedLogFiles_PicksUpAllVariants asserts that the rotated-log
+// glob picks up logs rotated by timberjack (gzipped) and by logrotate (plain
+// and gzipped), and skips unrelated files.
+func TestAddRotatedLogFiles_PicksUpAllVariants(t *testing.T) {
+	dir := t.TempDir()
+
+	writeFile(t, filepath.Join(dir, "client.log"), "active log\n")
+	writeFile(t, filepath.Join(dir, "other.log"), "unrelated\n")
+
+	timberjackRotated := "client-2026-05-21T10-30-45.000.log.gz"
+	writeGzFile(t, filepath.Join(dir, timberjackRotated), "timberjack rotated content\n")
+
+	logrotatePlain := "client.log.1"
+	writeFile(t, filepath.Join(dir, logrotatePlain), "logrotate plain content\n")
+
+	logrotateGz := "client.log.2.gz"
+	writeGzFile(t, filepath.Join(dir, logrotateGz), "logrotate gz content\n")
+
+	names := runAddRotatedLogFiles(t, dir, 10)
+
+	require.Contains(t, names, timberjackRotated, "timberjack rotated file should be in bundle")
+	require.Contains(t, names, logrotatePlain, "logrotate plain rotated file should be in bundle")
+	require.Contains(t, names, logrotateGz, "logrotate gzipped rotated file should be in bundle")
+	require.NotContains(t, names, "client.log", "active log should not be added by addRotatedLogFiles")
+	require.NotContains(t, names, "other.log", "unrelated files should not be in bundle")
+}
+
+// TestAddRotatedLogFiles_RespectsLogFileCount asserts that only the newest
+// logFileCount rotated files are bundled, ordered by mtime.
+func TestAddRotatedLogFiles_RespectsLogFileCount(t *testing.T) {
+	dir := t.TempDir()
+
+	oldest := filepath.Join(dir, "client.log.3")
+	middle := filepath.Join(dir, "client.log.2")
+	newest := filepath.Join(dir, "client.log.1")
+	writeFile(t, oldest, "old\n")
+	writeFile(t, middle, "mid\n")
+	writeFile(t, newest, "new\n")
+
+	now := time.Now()
+	require.NoError(t, os.Chtimes(oldest, now.Add(-2*time.Hour), now.Add(-2*time.Hour)))
+	require.NoError(t, os.Chtimes(middle, now.Add(-1*time.Hour), now.Add(-1*time.Hour)))
+	require.NoError(t, os.Chtimes(newest, now, now))
+
+	names := runAddRotatedLogFiles(t, dir, 2)
+
+	require.Contains(t, names, "client.log.1")
+	require.Contains(t, names, "client.log.2")
+	require.NotContains(t, names, "client.log.3", "oldest file should be dropped when logFileCount=2")
+}
+
+// runAddRotatedLogFiles calls addRotatedLogFiles against a fresh in-memory
+// zip writer and returns the set of entry names that ended up in the archive.
+func runAddRotatedLogFiles(t *testing.T, dir string, logFileCount uint32) map[string]struct{} {
+	t.Helper()
+
+	var buf bytes.Buffer
+	g := &BundleGenerator{
+		archive:      zip.NewWriter(&buf),
+		logFileCount: logFileCount,
+	}
+	g.addRotatedLogFiles(dir)
+	require.NoError(t, g.archive.Close())
+
+	zr, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))
+	require.NoError(t, err)
+
+	names := make(map[string]struct{}, len(zr.File))
+	for _, f := range zr.File {
+		names[f.Name] = struct{}{}
+	}
+	return names
+}
+
+func writeFile(t *testing.T, path, content string) {
+	t.Helper()
+	require.NoError(t, os.WriteFile(path, []byte(content), 0o644))
+}
+
+func writeGzFile(t *testing.T, path, content string) {
+	t.Helper()
+	var buf bytes.Buffer
+	gw := gzip.NewWriter(&buf)
+	_, err := io.WriteString(gw, content)
+	require.NoError(t, err)
+	require.NoError(t, gw.Close())
+	require.NoError(t, os.WriteFile(path, buf.Bytes(), 0o644))
+}