tailscale/logtail/filch/filch_test.go

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// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package filch
import (
"fmt"
"io/ioutil"
"os"
"runtime"
"strings"
"testing"
"unicode"
"unsafe"
)
type filchTest struct {
*Filch
}
func newFilchTest(t *testing.T, filePrefix string, opts Options) *filchTest {
f, err := New(filePrefix, opts)
if err != nil {
t.Fatal(err)
}
return &filchTest{Filch: f}
}
func (f *filchTest) write(t *testing.T, s string) {
t.Helper()
if _, err := f.Write([]byte(s)); err != nil {
t.Fatal(err)
}
}
func (f *filchTest) read(t *testing.T, want string) {
t.Helper()
if b, err := f.TryReadLine(); err != nil {
t.Fatalf("r.ReadLine() err=%v", err)
} else if got := strings.TrimRightFunc(string(b), unicode.IsSpace); got != want {
t.Errorf("r.ReadLine()=%q, want %q", got, want)
}
}
func (f *filchTest) readEOF(t *testing.T) {
t.Helper()
if b, err := f.TryReadLine(); b != nil || err != nil {
t.Fatalf("r.ReadLine()=%q err=%v, want nil slice", string(b), err)
}
}
func (f *filchTest) close(t *testing.T) {
t.Helper()
if err := f.Close(); err != nil {
t.Fatal(err)
}
}
func TestDropOldLogs(t *testing.T) {
const line1 = "123456789" // 10 bytes (9+newline)
tests := []struct {
write, read int
}{
{10, 10},
{100, 100},
{200, 200},
{250, 150},
{500, 200},
}
for _, tc := range tests {
t.Run(fmt.Sprintf("w%d-r%d", tc.write, tc.read), func(t *testing.T) {
filePrefix := t.TempDir()
f := newFilchTest(t, filePrefix, Options{ReplaceStderr: false, MaxFileSize: 1000})
defer f.close(t)
// Make filch rotate the logs 3 times
for i := 0; i < tc.write; i++ {
f.write(t, line1)
}
// We should only be able to read the last 150 lines
for i := 0; i < tc.read; i++ {
f.read(t, line1)
if t.Failed() {
t.Logf("could only read %d lines", i)
break
}
}
f.readEOF(t)
})
}
}
func TestQueue(t *testing.T) {
filePrefix := t.TempDir()
f := newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
f.readEOF(t)
const line1 = "Hello, World!"
const line2 = "This is a test."
const line3 = "Of filch."
f.write(t, line1)
f.write(t, line2)
f.read(t, line1)
f.write(t, line3)
f.read(t, line2)
f.read(t, line3)
f.readEOF(t)
f.write(t, line1)
f.read(t, line1)
f.readEOF(t)
f.close(t)
}
func TestRecover(t *testing.T) {
t.Run("empty", func(t *testing.T) {
filePrefix := t.TempDir()
f := newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
f.write(t, "hello")
f.read(t, "hello")
f.readEOF(t)
f.close(t)
f = newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
f.readEOF(t)
f.close(t)
})
t.Run("cur", func(t *testing.T) {
filePrefix := t.TempDir()
f := newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
f.write(t, "hello")
f.close(t)
f = newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
f.read(t, "hello")
f.readEOF(t)
f.close(t)
})
t.Run("alt", func(t *testing.T) {
t.Skip("currently broken on linux, passes on macOS")
/* --- FAIL: TestRecover/alt (0.00s)
filch_test.go:128: r.ReadLine()="world", want "hello"
filch_test.go:129: r.ReadLine()="hello", want "world"
*/
filePrefix := t.TempDir()
f := newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
f.write(t, "hello")
f.read(t, "hello")
f.write(t, "world")
f.close(t)
f = newFilchTest(t, filePrefix, Options{ReplaceStderr: false})
// TODO(crawshaw): The "hello" log is replayed in recovery.
// We could reduce replays by risking some logs loss.
// What should our policy here be?
f.read(t, "hello")
f.read(t, "world")
f.readEOF(t)
f.close(t)
})
}
func TestFilchStderr(t *testing.T) {
if runtime.GOOS == "windows" {
// TODO(bradfitz): this is broken on Windows but not
// fully sure why. Investigate. But notably, the
// stderrFD variable (defined in filch.go) and set
// below is only ever read in filch_unix.go. So just
// skip this for test for now.
t.Skip("test broken on Windows")
}
pipeR, pipeW, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer pipeR.Close()
defer pipeW.Close()
stderrFD = int(pipeW.Fd())
defer func() {
stderrFD = 2
}()
filePrefix := t.TempDir()
f := newFilchTest(t, filePrefix, Options{ReplaceStderr: true})
f.write(t, "hello")
if _, err := fmt.Fprintf(pipeW, "filch\n"); err != nil {
t.Fatal(err)
}
f.read(t, "hello")
f.read(t, "filch")
f.readEOF(t)
f.close(t)
pipeW.Close()
b, err := ioutil.ReadAll(pipeR)
if err != nil {
t.Fatal(err)
}
if len(b) > 0 {
t.Errorf("unexpected write to fake stderr: %s", b)
}
}
func TestSizeOf(t *testing.T) {
s := unsafe.Sizeof(Filch{})
if s > 4096 {
t.Fatalf("Filch{} has size %d on %v, decrease size of buf field", s, runtime.GOARCH)
}
}