From 4d895dcb5472da19b886ca1662182556242fe5d4 Mon Sep 17 00:00:00 2001 From: Brent Baude Date: Fri, 3 Apr 2020 14:56:10 -0500 Subject: v2podman attach and exec add the ability to attach to a running container. the tunnel side of this is not enabled yet as we have work on the endpoints and plumbing to do yet. add the ability to exec a command in a running container. the tunnel side is also being deferred for same reason. Signed-off-by: Brent Baude --- pkg/domain/infra/abi/containers.go | 72 ++++++++++++-- pkg/domain/infra/abi/terminal/sigproxy_linux.go | 47 +++++++++ pkg/domain/infra/abi/terminal/terminal.go | 103 ++++++++++++++++++++ pkg/domain/infra/abi/terminal/terminal_linux.go | 123 ++++++++++++++++++++++++ pkg/domain/infra/tunnel/containers.go | 8 ++ 5 files changed, 344 insertions(+), 9 deletions(-) create mode 100644 pkg/domain/infra/abi/terminal/sigproxy_linux.go create mode 100644 pkg/domain/infra/abi/terminal/terminal.go create mode 100644 pkg/domain/infra/abi/terminal/terminal_linux.go (limited to 'pkg/domain/infra') diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go index d3d51db82..b93e7665a 100644 --- a/pkg/domain/infra/abi/containers.go +++ b/pkg/domain/infra/abi/containers.go @@ -5,6 +5,7 @@ package abi import ( "context" "io/ioutil" + "strconv" "strings" "github.com/containers/buildah" @@ -12,9 +13,9 @@ import ( "github.com/containers/libpod/libpod" "github.com/containers/libpod/libpod/define" "github.com/containers/libpod/libpod/image" - "github.com/containers/libpod/pkg/adapter/shortcuts" "github.com/containers/libpod/pkg/checkpoint" "github.com/containers/libpod/pkg/domain/entities" + "github.com/containers/libpod/pkg/domain/infra/abi/terminal" "github.com/containers/libpod/pkg/signal" "github.com/containers/libpod/pkg/specgen" "github.com/containers/libpod/pkg/specgen/generate" @@ -64,7 +65,7 @@ func (ic *ContainerEngine) ContainerWait(ctx context.Context, namesOrIds []strin var ( responses []entities.WaitReport ) - ctrs, err := shortcuts.GetContainersByContext(false, options.Latest, namesOrIds, ic.Libpod) + ctrs, err := getContainersByContext(false, options.Latest, namesOrIds, ic.Libpod) if err != nil { return nil, err } @@ -90,7 +91,7 @@ func (ic *ContainerEngine) ContainerPause(ctx context.Context, namesOrIds []stri if options.All { ctrs, err = ic.Libpod.GetAllContainers() } else { - ctrs, err = shortcuts.GetContainersByContext(false, false, namesOrIds, ic.Libpod) + ctrs, err = getContainersByContext(false, false, namesOrIds, ic.Libpod) } if err != nil { return nil, err @@ -111,7 +112,7 @@ func (ic *ContainerEngine) ContainerUnpause(ctx context.Context, namesOrIds []st if options.All { ctrs, err = ic.Libpod.GetAllContainers() } else { - ctrs, err = shortcuts.GetContainersByContext(false, false, namesOrIds, ic.Libpod) + ctrs, err = getContainersByContext(false, false, namesOrIds, ic.Libpod) } if err != nil { return nil, err @@ -135,7 +136,7 @@ func (ic *ContainerEngine) ContainerStop(ctx context.Context, namesOrIds []strin id := strings.Split(string(content), "\n")[0] names = append(names, id) } - ctrs, err := shortcuts.GetContainersByContext(options.All, options.Latest, names, ic.Libpod) + ctrs, err := getContainersByContext(options.All, options.Latest, names, ic.Libpod) if err != nil && !(options.Ignore && errors.Cause(err) == define.ErrNoSuchCtr) { return nil, err } @@ -171,7 +172,7 @@ func (ic *ContainerEngine) ContainerKill(ctx context.Context, namesOrIds []strin if err != nil { return nil, err } - ctrs, err := shortcuts.GetContainersByContext(options.All, options.Latest, namesOrIds, ic.Libpod) + ctrs, err := getContainersByContext(options.All, options.Latest, namesOrIds, ic.Libpod) if err != nil { return nil, err } @@ -187,7 +188,7 @@ func (ic *ContainerEngine) ContainerRestart(ctx context.Context, namesOrIds []st var ( reports []*entities.RestartReport ) - ctrs, err := shortcuts.GetContainersByContext(options.All, options.Latest, namesOrIds, ic.Libpod) + ctrs, err := getContainersByContext(options.All, options.Latest, namesOrIds, ic.Libpod) if err != nil { return nil, err } @@ -229,7 +230,7 @@ func (ic *ContainerEngine) ContainerRm(ctx context.Context, namesOrIds []string, names = append(names, id) } - ctrs, err := shortcuts.GetContainersByContext(options.All, options.Latest, names, ic.Libpod) + ctrs, err := getContainersByContext(options.All, options.Latest, names, ic.Libpod) if err != nil && !(options.Ignore && errors.Cause(err) == define.ErrNoSuchCtr) { // Failed to get containers. If force is specified, get the containers ID // and evict them @@ -277,7 +278,7 @@ func (ic *ContainerEngine) ContainerRm(ctx context.Context, namesOrIds []string, func (ic *ContainerEngine) ContainerInspect(ctx context.Context, namesOrIds []string, options entities.InspectOptions) ([]*entities.ContainerInspectReport, error) { var reports []*entities.ContainerInspectReport - ctrs, err := shortcuts.GetContainersByContext(false, options.Latest, namesOrIds, ic.Libpod) + ctrs, err := getContainersByContext(false, options.Latest, namesOrIds, ic.Libpod) if err != nil { return nil, err } @@ -455,3 +456,56 @@ func (ic *ContainerEngine) ContainerCreate(ctx context.Context, s *specgen.SpecG } return &entities.ContainerCreateReport{Id: ctr.ID()}, nil } + +func (ic *ContainerEngine) ContainerAttach(ctx context.Context, nameOrId string, options entities.AttachOptions) error { + ctrs, err := getContainersByContext(false, options.Latest, []string{nameOrId}, ic.Libpod) + if err != nil { + return err + } + ctr := ctrs[0] + conState, err := ctr.State() + if err != nil { + return errors.Wrapf(err, "unable to determine state of %s", ctr.ID()) + } + if conState != define.ContainerStateRunning { + return errors.Errorf("you can only attach to running containers") + } + + // If the container is in a pod, also set to recursively start dependencies + if err := terminal.StartAttachCtr(ctx, ctr, options.Stdin, options.Stderr, options.Stdin, options.DetachKeys, options.SigProxy, false, ctr.PodID() != ""); err != nil && errors.Cause(err) != define.ErrDetach { + return errors.Wrapf(err, "error attaching to container %s", ctr.ID()) + } + return nil +} + +func (ic *ContainerEngine) ContainerExec(ctx context.Context, nameOrId string, options entities.ExecOptions) (int, error) { + ec := define.ExecErrorCodeGeneric + if options.PreserveFDs > 0 { + entries, err := ioutil.ReadDir("/proc/self/fd") + if err != nil { + return ec, errors.Wrapf(err, "unable to read /proc/self/fd") + } + + m := make(map[int]bool) + for _, e := range entries { + i, err := strconv.Atoi(e.Name()) + if err != nil { + return ec, errors.Wrapf(err, "cannot parse %s in /proc/self/fd", e.Name()) + } + m[i] = true + } + + for i := 3; i < 3+int(options.PreserveFDs); i++ { + if _, found := m[i]; !found { + return ec, errors.New("invalid --preserve-fds=N specified. Not enough FDs available") + } + } + } + ctrs, err := getContainersByContext(false, options.Latest, []string{nameOrId}, ic.Libpod) + if err != nil { + return ec, err + } + ctr := ctrs[0] + ec, err = terminal.ExecAttachCtr(ctx, ctr, options.Tty, options.Privileged, options.Envs, options.Cmd, options.User, options.WorkDir, &options.Streams, options.PreserveFDs, options.DetachKeys) + return define.TranslateExecErrorToExitCode(ec, err), err +} diff --git a/pkg/domain/infra/abi/terminal/sigproxy_linux.go b/pkg/domain/infra/abi/terminal/sigproxy_linux.go new file mode 100644 index 000000000..d7f5853d8 --- /dev/null +++ b/pkg/domain/infra/abi/terminal/sigproxy_linux.go @@ -0,0 +1,47 @@ +// +build ABISupport + +package terminal + +import ( + "os" + "syscall" + + "github.com/containers/libpod/libpod" + "github.com/containers/libpod/pkg/signal" + "github.com/sirupsen/logrus" +) + +// ProxySignals ... +func ProxySignals(ctr *libpod.Container) { + sigBuffer := make(chan os.Signal, 128) + signal.CatchAll(sigBuffer) + + logrus.Debugf("Enabling signal proxying") + + go func() { + for s := range sigBuffer { + // Ignore SIGCHLD and SIGPIPE - these are mostly likely + // intended for the podman command itself. + // SIGURG was added because of golang 1.14 and its preemptive changes + // causing more signals to "show up". + // https://github.com/containers/libpod/issues/5483 + if s == syscall.SIGCHLD || s == syscall.SIGPIPE || s == syscall.SIGURG { + continue + } + + if err := ctr.Kill(uint(s.(syscall.Signal))); err != nil { + // If the container dies, and we find out here, + // we need to forward that one signal to + // ourselves so that it is not lost, and then + // we terminate the proxy and let the defaults + // play out. + logrus.Errorf("Error forwarding signal %d to container %s: %v", s, ctr.ID(), err) + signal.StopCatch(sigBuffer) + if err := syscall.Kill(syscall.Getpid(), s.(syscall.Signal)); err != nil { + logrus.Errorf("failed to kill pid %d", syscall.Getpid()) + } + return + } + } + }() +} diff --git a/pkg/domain/infra/abi/terminal/terminal.go b/pkg/domain/infra/abi/terminal/terminal.go new file mode 100644 index 000000000..f187bdd6b --- /dev/null +++ b/pkg/domain/infra/abi/terminal/terminal.go @@ -0,0 +1,103 @@ +// +build ABISupport + +package terminal + +import ( + "context" + "os" + "os/signal" + + lsignal "github.com/containers/libpod/pkg/signal" + "github.com/docker/docker/pkg/term" + "github.com/pkg/errors" + "github.com/sirupsen/logrus" + "k8s.io/client-go/tools/remotecommand" +) + +// RawTtyFormatter ... +type RawTtyFormatter struct { +} + +// getResize returns a TerminalSize command matching stdin's current +// size on success, and nil on errors. +func getResize() *remotecommand.TerminalSize { + winsize, err := term.GetWinsize(os.Stdin.Fd()) + if err != nil { + logrus.Warnf("Could not get terminal size %v", err) + return nil + } + return &remotecommand.TerminalSize{ + Width: winsize.Width, + Height: winsize.Height, + } +} + +// Helper for prepareAttach - set up a goroutine to generate terminal resize events +func resizeTty(ctx context.Context, resize chan remotecommand.TerminalSize) { + sigchan := make(chan os.Signal, 1) + signal.Notify(sigchan, lsignal.SIGWINCH) + go func() { + defer close(resize) + // Update the terminal size immediately without waiting + // for a SIGWINCH to get the correct initial size. + resizeEvent := getResize() + for { + if resizeEvent == nil { + select { + case <-ctx.Done(): + return + case <-sigchan: + resizeEvent = getResize() + } + } else { + select { + case <-ctx.Done(): + return + case <-sigchan: + resizeEvent = getResize() + case resize <- *resizeEvent: + resizeEvent = nil + } + } + } + }() +} + +func restoreTerminal(state *term.State) error { + logrus.SetFormatter(&logrus.TextFormatter{}) + return term.RestoreTerminal(os.Stdin.Fd(), state) +} + +// Format ... +func (f *RawTtyFormatter) Format(entry *logrus.Entry) ([]byte, error) { + textFormatter := logrus.TextFormatter{} + bytes, err := textFormatter.Format(entry) + + if err == nil { + bytes = append(bytes, '\r') + } + + return bytes, err +} + +func handleTerminalAttach(ctx context.Context, resize chan remotecommand.TerminalSize) (context.CancelFunc, *term.State, error) { + logrus.Debugf("Handling terminal attach") + + subCtx, cancel := context.WithCancel(ctx) + + resizeTty(subCtx, resize) + + oldTermState, err := term.SaveState(os.Stdin.Fd()) + if err != nil { + // allow caller to not have to do any cleaning up if we error here + cancel() + return nil, nil, errors.Wrapf(err, "unable to save terminal state") + } + + logrus.SetFormatter(&RawTtyFormatter{}) + if _, err := term.SetRawTerminal(os.Stdin.Fd()); err != nil { + return cancel, nil, err + } + + return cancel, oldTermState, nil +} diff --git a/pkg/domain/infra/abi/terminal/terminal_linux.go b/pkg/domain/infra/abi/terminal/terminal_linux.go new file mode 100644 index 000000000..664205df1 --- /dev/null +++ b/pkg/domain/infra/abi/terminal/terminal_linux.go @@ -0,0 +1,123 @@ +// +build ABISupport + +package terminal + +import ( + "bufio" + "context" + "fmt" + "os" + + "github.com/containers/libpod/libpod" + "github.com/containers/libpod/libpod/define" + "github.com/pkg/errors" + "github.com/sirupsen/logrus" + "golang.org/x/crypto/ssh/terminal" + "k8s.io/client-go/tools/remotecommand" +) + +// ExecAttachCtr execs and attaches to a container +func ExecAttachCtr(ctx context.Context, ctr *libpod.Container, tty, privileged bool, env map[string]string, cmd []string, user, workDir string, streams *define.AttachStreams, preserveFDs uint, detachKeys string) (int, error) { + resize := make(chan remotecommand.TerminalSize) + haveTerminal := terminal.IsTerminal(int(os.Stdin.Fd())) + + // Check if we are attached to a terminal. If we are, generate resize + // events, and set the terminal to raw mode + if haveTerminal && tty { + cancel, oldTermState, err := handleTerminalAttach(ctx, resize) + if err != nil { + return -1, err + } + defer cancel() + defer func() { + if err := restoreTerminal(oldTermState); err != nil { + logrus.Errorf("unable to restore terminal: %q", err) + } + }() + } + + execConfig := new(libpod.ExecConfig) + execConfig.Command = cmd + execConfig.Terminal = tty + execConfig.Privileged = privileged + execConfig.Environment = env + execConfig.User = user + execConfig.WorkDir = workDir + execConfig.DetachKeys = &detachKeys + execConfig.PreserveFDs = preserveFDs + + return ctr.Exec(execConfig, streams, resize) +} + +// StartAttachCtr starts and (if required) attaches to a container +// if you change the signature of this function from os.File to io.Writer, it will trigger a downstream +// error. we may need to just lint disable this one. +func StartAttachCtr(ctx context.Context, ctr *libpod.Container, stdout, stderr, stdin *os.File, detachKeys string, sigProxy bool, startContainer bool, recursive bool) error { //nolint-interfacer + resize := make(chan remotecommand.TerminalSize) + + haveTerminal := terminal.IsTerminal(int(os.Stdin.Fd())) + + // Check if we are attached to a terminal. If we are, generate resize + // events, and set the terminal to raw mode + if haveTerminal && ctr.Spec().Process.Terminal { + cancel, oldTermState, err := handleTerminalAttach(ctx, resize) + if err != nil { + return err + } + defer func() { + if err := restoreTerminal(oldTermState); err != nil { + logrus.Errorf("unable to restore terminal: %q", err) + } + }() + defer cancel() + } + + streams := new(define.AttachStreams) + streams.OutputStream = stdout + streams.ErrorStream = stderr + streams.InputStream = bufio.NewReader(stdin) + streams.AttachOutput = true + streams.AttachError = true + streams.AttachInput = true + + if stdout == nil { + logrus.Debugf("Not attaching to stdout") + streams.AttachOutput = false + } + if stderr == nil { + logrus.Debugf("Not attaching to stderr") + streams.AttachError = false + } + if stdin == nil { + logrus.Debugf("Not attaching to stdin") + streams.AttachInput = false + } + + if !startContainer { + if sigProxy { + ProxySignals(ctr) + } + + return ctr.Attach(streams, detachKeys, resize) + } + + attachChan, err := ctr.StartAndAttach(ctx, streams, detachKeys, resize, recursive) + if err != nil { + return err + } + + if sigProxy { + ProxySignals(ctr) + } + + if stdout == nil && stderr == nil { + fmt.Printf("%s\n", ctr.ID()) + } + + err = <-attachChan + if err != nil { + return errors.Wrapf(err, "error attaching to container %s", ctr.ID()) + } + + return nil +} diff --git a/pkg/domain/infra/tunnel/containers.go b/pkg/domain/infra/tunnel/containers.go index ae8994cba..1e71cba2c 100644 --- a/pkg/domain/infra/tunnel/containers.go +++ b/pkg/domain/infra/tunnel/containers.go @@ -305,3 +305,11 @@ func (ic *ContainerEngine) ContainerCreate(ctx context.Context, s *specgen.SpecG } return &entities.ContainerCreateReport{Id: response.ID}, nil } + +func (ic *ContainerEngine) ContainerAttach(ctx context.Context, nameOrId string, options entities.AttachOptions) error { + return errors.New("not implemented") +} + +func (ic *ContainerEngine) ContainerExec(ctx context.Context, nameOrId string, options entities.ExecOptions) (int, error) { + return 125, errors.New("not implemented") +} -- cgit v1.2.3-54-g00ecf