logmon: add tests for rotation and open/closing of fifos

client/logmon/logmon_test.go

@@ -0,0 +1,120 @@
+package logmon
+
+import (
+	"bytes"
+	"crypto/rand"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/hashicorp/nomad/client/lib/fifo"
+	"github.com/hashicorp/nomad/helper/testlog"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLogmon_Start_rotate(t *testing.T) {
+	require := require.New(t)
+	dir, err := ioutil.TempDir("", "nomadtest")
+	require.NoError(err)
+	defer os.RemoveAll(dir)
+	stdoutLog := "stdout"
+	stdoutFifoPath := filepath.Join(dir, "stdout.fifo")
+	stderrLog := "stderr"
+	stderrFifoPath := filepath.Join(dir, "stderr.fifo")
+
+	cfg := &LogConfig{
+		LogDir:        dir,
+		StdoutLogFile: stdoutLog,
+		StdoutFifo:    stdoutFifoPath,
+		StderrLogFile: stderrLog,
+		StderrFifo:    stderrFifoPath,
+		MaxFiles:      2,
+		MaxFileSizeMB: 1,
+	}
+
+	lm := NewLogMon(testlog.HCLogger(t))
+	require.NoError(lm.Start(cfg))
+
+	stdout, err := fifo.Open(stdoutFifoPath)
+	require.NoError(err)
+
+	// Write enough bytes such that the log is rotated
+	bytes1MB := make([]byte, 1024*1024)
+	_, err = rand.Read(bytes1MB)
+	require.NoError(err)
+
+	io.Copy(stdout, bytes.NewBuffer(bytes1MB))
+
+	time.Sleep(200 * time.Millisecond)
+	_, err = os.Stat(filepath.Join(dir, "stdout.0"))
+	require.NoError(err)
+	_, err = os.Stat(filepath.Join(dir, "stdout.1"))
+	require.NoError(err)
+
+	require.NoError(lm.Stop())
+}
+
+func TestLogmon_Start_restart(t *testing.T) {
+	require := require.New(t)
+	dir, err := ioutil.TempDir("", "nomadtest")
+	require.NoError(err)
+	defer os.RemoveAll(dir)
+	stdoutLog := "stdout"
+	stdoutFifoPath := filepath.Join(dir, "stdout.fifo")
+	stderrLog := "stderr"
+	stderrFifoPath := filepath.Join(dir, "stderr.fifo")
+
+	cfg := &LogConfig{
+		LogDir:        dir,
+		StdoutLogFile: stdoutLog,
+		StdoutFifo:    stdoutFifoPath,
+		StderrLogFile: stderrLog,
+		StderrFifo:    stderrFifoPath,
+		MaxFiles:      2,
+		MaxFileSizeMB: 1,
+	}
+
+	lm := NewLogMon(testlog.HCLogger(t))
+	impl, ok := lm.(*logmonImpl)
+	require.True(ok)
+	require.NoError(lm.Start(cfg))
+
+	stdout, err := fifo.Open(stdoutFifoPath)
+	require.NoError(err)
+	stderr, err := fifo.Open(stderrFifoPath)
+	require.NoError(err)
+
+	// Write a string and assert it was written to the file
+	io.Copy(stdout, bytes.NewBufferString("test\n"))
+	time.Sleep(200 * time.Millisecond)
+	raw, err := ioutil.ReadFile(filepath.Join(dir, "stdout.0"))
+	require.NoError(err)
+	require.Equal("test\n", string(raw))
+	require.True(impl.tl.IsRunning())
+
+	// Close stdout and assert that logmon no longer writes to the file
+	require.NoError(stdout.Close())
+	require.NoError(stderr.Close())
+
+	stdout, err = fifo.Open(stdoutFifoPath)
+	require.NoError(err)
+	stderr, err = fifo.Open(stderrFifoPath)
+	require.NoError(err)
+	require.False(impl.tl.IsRunning())
+	io.Copy(stdout, bytes.NewBufferString("te"))
+	time.Sleep(200 * time.Millisecond)
+	raw, err = ioutil.ReadFile(filepath.Join(dir, "stdout.0"))
+	require.NoError(err)
+	require.Equal("test\n", string(raw))
+
+	// Start logmon again and assert that it appended to the file
+	require.NoError(lm.Start(cfg))
+	io.Copy(stdout, bytes.NewBufferString("st\n"))
+	time.Sleep(200 * time.Millisecond)
+	raw, err = ioutil.ReadFile(filepath.Join(dir, "stdout.0"))
+	require.NoError(err)
+	require.Equal("test\ntest\n", string(raw))
+}