etcd/pkg/expect/expect_test.go
Wei Fu 56edfa6e28 pkg/expect: fix data race
Let's say there is command which outputs one line and exit with error.

There are three goroutines to acquire the lock:

1. ep.read()
2. ep.waitSaveExitErr()
3. ep.Expect()

When ep.read goroutine reads the log but it doesn't acquire the lock in
time, the ep.waitSaveExitErr acquires the lock and updates the
`exitErr`. And then ep.Expect acquires lock but it doesn't see any log
yet and then returns err.

It's hard to reproduce it in local. Add the extra sleep can reproduce it.

```diff
diff --git a/pkg/expect/expect.go b/pkg/expect/expect.go
index a512a3ce4..602bea73f 100644
--- a/pkg/expect/expect.go
+++ b/pkg/expect/expect.go
@@ -128,6 +128,7 @@ func (ep *ExpectProcess) tryReadNextLine(r *bufio.Reader) error {
        printDebugLines := os.Getenv("EXPECT_DEBUG") != ""
        l, err := r.ReadString('\n')

+       time.Sleep(10 * time.Millisecond)
        ep.mu.Lock()
        defer ep.mu.Unlock()
```

See it once in Github Action [1]. In order to fix it, the patch introduces
`readCloseCh` to wait for ep.read to get all the data and retry it.

[1]: https://github.com/etcd-io/etcd/pull/16137#issuecomment-1605838518

Signed-off-by: Wei Fu <fuweid89@gmail.com>
2023-07-13 14:56:21 +08:00

221 lines
5.3 KiB
Go

// Copyright 2016 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// build !windows
package expect
import (
"context"
"os"
"strings"
"testing"
"time"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestExpectFunc(t *testing.T) {
ep, err := NewExpect("echo", "hello world")
if err != nil {
t.Fatal(err)
}
wstr := "hello world\r\n"
l, eerr := ep.ExpectFunc(context.Background(), func(a string) bool { return len(a) > 10 })
if eerr != nil {
t.Fatal(eerr)
}
if l != wstr {
t.Fatalf(`got "%v", expected "%v"`, l, wstr)
}
if cerr := ep.Close(); cerr != nil {
t.Fatal(cerr)
}
}
func TestExpectFuncTimeout(t *testing.T) {
ep, err := NewExpect("tail", "-f", "/dev/null")
if err != nil {
t.Fatal(err)
}
go func() {
// It's enough to have "talkative" process to stuck in the infinite loop of reading
for {
err := ep.Send("new line\n")
if err != nil {
return
}
}
}()
ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
defer cancel()
_, err = ep.ExpectFunc(ctx, func(a string) bool { return false })
require.ErrorAs(t, err, &context.DeadlineExceeded)
if err := ep.Stop(); err != nil {
t.Fatal(err)
}
err = ep.Close()
require.ErrorContains(t, err, "unexpected exit code [143] after running [/usr/bin/tail -f /dev/null]")
require.Equal(t, 143, ep.exitCode)
}
func TestExpectFuncExitFailure(t *testing.T) {
// tail -x should not exist and return a non-zero exit code
ep, err := NewExpect("tail", "-x")
if err != nil {
t.Fatal(err)
}
ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
defer cancel()
_, err = ep.ExpectFunc(ctx, func(s string) bool {
return strings.Contains(s, "something entirely unexpected")
})
require.ErrorContains(t, err, "unexpected exit code [1] after running [/usr/bin/tail -x]")
require.Equal(t, 1, ep.exitCode)
}
func TestExpectFuncExitFailureStop(t *testing.T) {
// tail -x should not exist and return a non-zero exit code
ep, err := NewExpect("tail", "-x")
if err != nil {
t.Fatal(err)
}
ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
defer cancel()
_, err = ep.ExpectFunc(ctx, func(s string) bool {
return strings.Contains(s, "something entirely unexpected")
})
require.ErrorContains(t, err, "unexpected exit code [1] after running [/usr/bin/tail -x]")
exitCode, err := ep.ExitCode()
require.Equal(t, 1, exitCode)
require.NoError(t, err)
if err := ep.Stop(); err != nil {
t.Fatal(err)
}
err = ep.Close()
require.ErrorContains(t, err, "unexpected exit code [1] after running [/usr/bin/tail -x]")
exitCode, err = ep.ExitCode()
require.Equal(t, 1, exitCode)
require.NoError(t, err)
}
func TestEcho(t *testing.T) {
ep, err := NewExpect("echo", "hello world")
if err != nil {
t.Fatal(err)
}
ctx := context.Background()
l, eerr := ep.ExpectWithContext(ctx, "world")
if eerr != nil {
t.Fatal(eerr)
}
wstr := "hello world"
if l[:len(wstr)] != wstr {
t.Fatalf(`got "%v", expected "%v"`, l, wstr)
}
if cerr := ep.Close(); cerr != nil {
t.Fatal(cerr)
}
if _, eerr = ep.ExpectWithContext(ctx, "..."); eerr == nil {
t.Fatalf("expected error on closed expect process")
}
}
func TestLineCount(t *testing.T) {
ep, err := NewExpect("printf", "1\n2\n3")
if err != nil {
t.Fatal(err)
}
wstr := "3"
l, eerr := ep.ExpectWithContext(context.Background(), wstr)
if eerr != nil {
t.Fatal(eerr)
}
if l != wstr {
t.Fatalf(`got "%v", expected "%v"`, l, wstr)
}
if ep.LineCount() != 3 {
t.Fatalf("got %d, expected 3", ep.LineCount())
}
if cerr := ep.Close(); cerr != nil {
t.Fatal(cerr)
}
}
func TestSend(t *testing.T) {
ep, err := NewExpect("tr", "a", "b")
if err != nil {
t.Fatal(err)
}
if err := ep.Send("a\r"); err != nil {
t.Fatal(err)
}
if _, err := ep.ExpectWithContext(context.Background(), "b"); err != nil {
t.Fatal(err)
}
if err := ep.Stop(); err != nil {
t.Fatal(err)
}
}
func TestSignal(t *testing.T) {
ep, err := NewExpect("sleep", "100")
if err != nil {
t.Fatal(err)
}
ep.Signal(os.Interrupt)
donec := make(chan struct{})
go func() {
defer close(donec)
err = ep.Close()
assert.ErrorContains(t, err, "unexpected exit code [130]")
assert.ErrorContains(t, err, "sleep 100")
}()
select {
case <-time.After(5 * time.Second):
t.Fatalf("signal test timed out")
case <-donec:
}
}
func TestExitCodeAfterKill(t *testing.T) {
ep, err := NewExpect("sleep", "100")
require.NoError(t, err)
ep.Signal(os.Kill)
ep.Wait()
code, err := ep.ExitCode()
assert.Equal(t, 137, code)
assert.NoError(t, err)
}
func TestExpectForFailFastCommand(t *testing.T) {
ep, err := NewExpect("sh", "-c", `echo "curl: (59) failed setting cipher list"; exit 59`)
require.NoError(t, err)
_, err = ep.Expect("failed setting cipher list")
require.NoError(t, err)
}