diff options
-rw-r--r-- | pkg/systemd/notifyproxy/notifyproxy.go | 98 |
1 files changed, 63 insertions, 35 deletions
diff --git a/pkg/systemd/notifyproxy/notifyproxy.go b/pkg/systemd/notifyproxy/notifyproxy.go index 1bfab9ca0..32fea48bf 100644 --- a/pkg/systemd/notifyproxy/notifyproxy.go +++ b/pkg/systemd/notifyproxy/notifyproxy.go @@ -1,6 +1,7 @@ package notifyproxy import ( + "context" "errors" "fmt" "io" @@ -110,48 +111,75 @@ func (p *NotifyProxy) WaitAndClose() error { } }() - const bufferSize = 1024 - sBuilder := strings.Builder{} - for { - // Set a read deadline of one second such that we achieve a - // non-blocking read and can check if the container has already - // stopped running; in that case no READY message will be send - // and we're done. - if err := p.connection.SetReadDeadline(time.Now().Add(time.Second)); err != nil { - return err - } - + // Since reading from the connection is blocking, we need to spin up two + // goroutines. One waiting for the `READY` message, the other waiting + // for the container to stop running. + errorChan := make(chan error, 1) + readyChan := make(chan bool, 1) + + go func() { + // Read until the `READY` message is received or the connection + // is closed. + const bufferSize = 1024 + sBuilder := strings.Builder{} for { - buffer := make([]byte, bufferSize) - num, err := p.connection.Read(buffer) - if err != nil { - if !errors.Is(err, os.ErrDeadlineExceeded) && !errors.Is(err, io.EOF) { - return err + for { + buffer := make([]byte, bufferSize) + num, err := p.connection.Read(buffer) + if err != nil { + if !errors.Is(err, io.EOF) { + errorChan <- err + return + } + } + sBuilder.Write(buffer[:num]) + if num != bufferSize || buffer[num-1] == '\n' { + // Break as we read an entire line that + // we can inspect for the `READY` + // message. + break } } - sBuilder.Write(buffer[:num]) - if num != bufferSize || buffer[num-1] == '\n' { - break - } - } - for _, line := range strings.Split(sBuilder.String(), "\n") { - if line == daemon.SdNotifyReady { - return nil + for _, line := range strings.Split(sBuilder.String(), "\n") { + if line == daemon.SdNotifyReady { + readyChan <- true + return + } } + sBuilder.Reset() } - sBuilder.Reset() + }() - if p.container == nil { - continue - } + if p.container != nil { + // Create a cancellable context to make sure the goroutine + // below terminates. + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + go func() { + select { + case <-ctx.Done(): + return + default: + state, err := p.container.State() + if err != nil { + errorChan <- err + return + } + if state != define.ContainerStateRunning { + errorChan <- fmt.Errorf("%w: %s", ErrNoReadyMessage, p.container.ID()) + return + } + time.Sleep(time.Second) + } + }() + } - state, err := p.container.State() - if err != nil { - return err - } - if state != define.ContainerStateRunning { - return fmt.Errorf("%w: %s", ErrNoReadyMessage, p.container.ID()) - } + // Wait for the ready/error channel. + select { + case <-readyChan: + return nil + case err := <-errorChan: + return err } } |