logs: adjust handling around partial log messages

In libpod/logs.LogLine.Write(), don't write a newline to stdout/stderr
when the log message is only part of a line.

In libpod.ConmonOCIRuntime.HTTPAttach(), don't send a newline over the
HTTP connection when the log message is only part of a line.

In pkg/api/handlers/compat.LogsFromContainer(), don't send a newline
over the HTTP connection when the log message is only part of a line,
and don't make doing so conditional on whether or not the client used
the docker or podman endpoint.

In pkg/domain/infra/tunnel.ContainerEngine.ContainerLogs(), don't add
our own newline to log messages, since they already come through from
the server when they need to.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

libpod/logs/log.go

@@ -251,11 +251,19 @@ func (l *LogLine) Write(stdout io.Writer, stderr io.Writer, logOpts *LogOptions)
 	switch l.Device {
 	case "stdout":
 		if stdout != nil {
-			fmt.Fprintln(stdout, l.String(logOpts))
+			if l.Partial() {
+				fmt.Fprint(stdout, l.String(logOpts))
+			} else {
+				fmt.Fprintln(stdout, l.String(logOpts))
+			}
 		}
 	case "stderr":
 		if stderr != nil {
-			fmt.Fprintln(stderr, l.String(logOpts))
+			if l.Partial() {
+				fmt.Fprint(stderr, l.String(logOpts))
+			} else {
+				fmt.Fprintln(stderr, l.String(logOpts))
+			}
 		}
 	default:
 		// Warn the user if the device type does not match. Most likely the file is corrupted.

libpod/oci_conmon_linux.go

@@ -625,9 +625,11 @@ func (r *ConmonOCIRuntime) HTTPAttach(ctr *Container, req *http.Request, w http.
 				if err != nil {
 					break
 				}
-				_, err = httpBuf.Write([]byte("\n"))
-				if err != nil {
-					break
+				if !logLine.Partial() {
+					_, err = httpBuf.Write([]byte("\n"))
+					if err != nil {
+						break
+					}
 				}
 				err = httpBuf.Flush()
 				if err != nil {

pkg/api/handlers/compat/containers_logs.go

@@ -152,9 +152,7 @@ func LogsFromContainer(w http.ResponseWriter, r *http.Request) {
 		}
 
 		frame.WriteString(line.Msg)
-		// Log lines in the compat layer require adding EOL
-		// https://github.com/containers/podman/issues/8058
-		if !utils.IsLibpodRequest(r) {
+		if !line.Partial() {
 			frame.WriteString("\n")
 		}
 

pkg/domain/infra/tunnel/containers.go

@@ -404,11 +404,11 @@ func (ic *ContainerEngine) ContainerLogs(_ context.Context, nameOrIDs []string,
 			return err
 		case line := <-stdoutCh:
 			if opts.StdoutWriter != nil {
-				_, _ = io.WriteString(opts.StdoutWriter, line+"\n")
+				_, _ = io.WriteString(opts.StdoutWriter, line)
 			}
 		case line := <-stderrCh:
 			if opts.StderrWriter != nil {
-				_, _ = io.WriteString(opts.StderrWriter, line+"\n")
+				_, _ = io.WriteString(opts.StderrWriter, line)
 			}
 		}
 	}