Make sure we wait for stdout/stderr pipes to be closed before calling…

… runner.Wait()

client.go

@@ -104,9 +104,9 @@ type Client struct {
  // goroutines.
  clientWaitGroup sync.WaitGroup
 
- // stderrWaitGroup is used to prevent the command's Wait() function from
- // being called before we've finished reading from the stderr pipe.
- stderrWaitGroup sync.WaitGroup
+ // pipesWaitGroup is used to prevent the command's Wait() function from
+ // being called before we've finished reading from the stdout and stderr pipe.
+ pipesWaitGroup sync.WaitGroup
 
  // processKilled is used for testing only, to flag when the process was
  // forcefully killed.
@@ -756,8 +756,8 @@ func (c *Client) Start() (addr net.Addr, err error) {
 
  // Start goroutine that logs the stderr
  c.clientWaitGroup.Add(1)
- c.stderrWaitGroup.Add(1)
- // logStderr calls Done()
+ c.pipesWaitGroup.Add(1)
+ // logStderr calls c.pipesWaitGroup.Done()
  go c.logStderr(runner.Name(), runner.Stderr())
 
  c.clientWaitGroup.Add(1)
@@ -767,9 +767,9 @@ func (c *Client) Start() (addr net.Addr, err error) {
 
  defer c.clientWaitGroup.Done()
 
- // wait to finish reading from stderr since the stderr pipe reader
+ // wait to finish reading from stdout/stderr since the stdout/stderr pipe readers
  // will be closed by the subsequent call to cmd.Wait().
- c.stderrWaitGroup.Wait()
+ c.pipesWaitGroup.Wait()
 
  // Wait for the command to end.
  err := runner.Wait(context.Background())
@@ -792,8 +792,10 @@ func (c *Client) Start() (addr net.Addr, err error) {
  // out of stdout
  linesCh := make(chan string)
  c.clientWaitGroup.Add(1)
+ c.pipesWaitGroup.Add(1)
  go func() {
  defer c.clientWaitGroup.Done()
+ defer c.pipesWaitGroup.Done()
  defer close(linesCh)
 
  scanner := bufio.NewScanner(runner.Stdout())
@@ -1159,7 +1161,7 @@ func (c *Client) getGRPCMuxer(addr net.Addr) (*grpcmux.GRPCClientMuxer, error) {
 
 func (c *Client) logStderr(name string, r io.Reader) {
  defer c.clientWaitGroup.Done()
- defer c.stderrWaitGroup.Done()
+ defer c.pipesWaitGroup.Done()
  l := c.logger.Named(filepath.Base(name))
 
  reader := bufio.NewReaderSize(r, c.config.PluginLogBufferSize)

client_test.go

@@ -1503,7 +1503,7 @@ this line is short
 
  reader := strings.NewReader(msg)
 
- c.stderrWaitGroup.Add(1)
+ c.pipesWaitGroup.Add(1)
  c.logStderr(c.config.Cmd.Path, reader)
  read := stderr.String()
 
@@ -1531,7 +1531,7 @@ func TestClient_logStderrParseJSON(t *testing.T) {
 {"@message": "this is a large message that is more than 64 bytes long", "@level": "info"}`
  reader := strings.NewReader(msg)
 
- c.stderrWaitGroup.Add(1)
+ c.pipesWaitGroup.Add(1)
  c.logStderr(c.config.Cmd.Path, reader)
  logs := strings.Split(strings.TrimSpace(logBuf.String()), "\n")