From 26eae3bf89bcaf486ee297088102161d9c02311a Mon Sep 17 00:00:00 2001 From: Paul Holzinger Date: Thu, 3 Jun 2021 16:07:43 +0200 Subject: remote: always send resize before the container starts There is race condition in the remote client attach logic. Because the resize api call was handled in an extra goroutine the container was started before the resize call happend. To fix this we have to call resize in the same goroutine as attach. When the first resize is done start a goroutine to listen on SIGWINCH in the background and resize again if the signal is received. Fixes #9859 Signed-off-by: Paul Holzinger Signed-off-by: Matthew Heon --- pkg/api/handlers/compat/resize.go | 15 +++------- pkg/api/server/register_containers.go | 2 ++ pkg/bindings/containers/attach.go | 54 +++++++++++++++++++---------------- test/system/450-interactive.bats | 3 +- 4 files changed, 37 insertions(+), 37 deletions(-) diff --git a/pkg/api/handlers/compat/resize.go b/pkg/api/handlers/compat/resize.go index 23ed33a22..f65e313fc 100644 --- a/pkg/api/handlers/compat/resize.go +++ b/pkg/api/handlers/compat/resize.go @@ -46,20 +46,13 @@ func ResizeTTY(w http.ResponseWriter, r *http.Request) { utils.ContainerNotFound(w, name, err) return } - if state, err := ctnr.State(); err != nil { - utils.InternalServerError(w, errors.Wrapf(err, "cannot obtain container state")) - return - } else if state != define.ContainerStateRunning && !query.IgnoreNotRunning { - utils.Error(w, "Container not running", http.StatusConflict, - fmt.Errorf("container %q in wrong state %q", name, state.String())) - return - } - // If container is not running, ignore since this can be a race condition, and is expected if err := ctnr.AttachResize(sz); err != nil { - if errors.Cause(err) != define.ErrCtrStateInvalid || !query.IgnoreNotRunning { + if errors.Cause(err) != define.ErrCtrStateInvalid { utils.InternalServerError(w, errors.Wrapf(err, "cannot resize container")) - return + } else { + utils.Error(w, "Container not running", http.StatusConflict, err) } + return } // This is not a 204, even though we write nothing, for compatibility // reasons. diff --git a/pkg/api/server/register_containers.go b/pkg/api/server/register_containers.go index 536c4707a..2a6e8e286 100644 --- a/pkg/api/server/register_containers.go +++ b/pkg/api/server/register_containers.go @@ -1359,6 +1359,8 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error { // $ref: "#/responses/ok" // 404: // $ref: "#/responses/NoSuchContainer" + // 409: + // $ref: "#/responses/ConflictError" // 500: // $ref: "#/responses/InternalError" r.HandleFunc(VersionedPath("/libpod/containers/{name}/resize"), s.APIHandler(compat.ResizeTTY)).Methods(http.MethodPost) diff --git a/pkg/bindings/containers/attach.go b/pkg/bindings/containers/attach.go index fd8a7011d..adef1e7c8 100644 --- a/pkg/bindings/containers/attach.go +++ b/pkg/bindings/containers/attach.go @@ -138,7 +138,7 @@ func Attach(ctx context.Context, nameOrID string, stdin io.Reader, stdout io.Wri winCtx, winCancel := context.WithCancel(ctx) defer winCancel() - go attachHandleResize(ctx, winCtx, winChange, false, nameOrID, file) + attachHandleResize(ctx, winCtx, winChange, false, nameOrID, file) } // If we are attaching around a start, we need to "signal" @@ -327,32 +327,38 @@ func (f *rawFormatter) Format(entry *logrus.Entry) ([]byte, error) { return append(buffer, '\r'), nil } -// This is intended to be run as a goroutine, handling resizing for a container -// or exec session. +// This is intended to not be run as a goroutine, handling resizing for a container +// or exec session. It will call resize once and then starts a goroutine which calls resize on winChange func attachHandleResize(ctx, winCtx context.Context, winChange chan os.Signal, isExec bool, id string, file *os.File) { - // Prime the pump, we need one reset to ensure everything is ready - winChange <- sig.SIGWINCH - for { - select { - case <-winCtx.Done(): - return - case <-winChange: - w, h, err := terminal.GetSize(int(file.Fd())) - if err != nil { - logrus.Warnf("failed to obtain TTY size: %v", err) - } + resize := func() { + w, h, err := terminal.GetSize(int(file.Fd())) + if err != nil { + logrus.Warnf("failed to obtain TTY size: %v", err) + } - var resizeErr error - if isExec { - resizeErr = ResizeExecTTY(ctx, id, new(ResizeExecTTYOptions).WithHeight(h).WithWidth(w)) - } else { - resizeErr = ResizeContainerTTY(ctx, id, new(ResizeTTYOptions).WithHeight(h).WithWidth(w)) - } - if resizeErr != nil { - logrus.Warnf("failed to resize TTY: %v", resizeErr) - } + var resizeErr error + if isExec { + resizeErr = ResizeExecTTY(ctx, id, new(ResizeExecTTYOptions).WithHeight(h).WithWidth(w)) + } else { + resizeErr = ResizeContainerTTY(ctx, id, new(ResizeTTYOptions).WithHeight(h).WithWidth(w)) + } + if resizeErr != nil { + logrus.Warnf("failed to resize TTY: %v", resizeErr) } } + + resize() + + go func() { + for { + select { + case <-winCtx.Done(): + return + case <-winChange: + resize() + } + } + }() } // Configure the given terminal for raw mode @@ -457,7 +463,7 @@ func ExecStartAndAttach(ctx context.Context, sessionID string, options *ExecStar winCtx, winCancel := context.WithCancel(ctx) defer winCancel() - go attachHandleResize(ctx, winCtx, winChange, true, sessionID, terminalFile) + attachHandleResize(ctx, winCtx, winChange, true, sessionID, terminalFile) } if options.GetAttachInput() { diff --git a/test/system/450-interactive.bats b/test/system/450-interactive.bats index a9bf52ee8..a2db39492 100644 --- a/test/system/450-interactive.bats +++ b/test/system/450-interactive.bats @@ -56,8 +56,7 @@ function teardown() { stty rows $rows cols $cols <$PODMAN_TEST_PTY # ...and make sure stty under podman reads that. - # FIXME: 'sleep 1' is needed for podman-remote; without it, there's - run_podman run -it --name mystty $IMAGE sh -c 'sleep 1;stty size' <$PODMAN_TEST_PTY + run_podman run -it --name mystty $IMAGE stty size <$PODMAN_TEST_PTY is "$output" "$rows $cols" "stty under podman reads the correct dimensions" } -- cgit v1.2.3-54-g00ecf