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 <bbaude@redhat.com>

7 files changed, 375 insertions, 9 deletions

diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go
index 74b23cd71..cf907eb1b 100644
--- a/pkg/domain/entities/containers.go
+++ b/pkg/domain/entities/containers.go
@@ -2,6 +2,7 @@ package entities
 
 import (
 	"io"
+	"os"
 	"time"
 
 	"github.com/containers/libpod/libpod/define"
@@ -157,3 +158,31 @@ type RestoreReport struct {
 type ContainerCreateReport struct {
 	Id string
 }
+
+// AttachOptions describes the cli and other values
+// needed to perform an attach
+type AttachOptions struct {
+	DetachKeys string
+	Latest     bool
+	NoStdin    bool
+	SigProxy   bool
+	Stdin      *os.File
+	Stdout     *os.File
+	Stderr     *os.File
+}
+
+// ExecOptions describes the cli values to exec into
+// a container
+type ExecOptions struct {
+	Cmd         []string
+	DetachKeys  string
+	Envs        map[string]string
+	Interactive bool
+	Latest      bool
+	PreserveFDs uint
+	Privileged  bool
+	Streams     define.AttachStreams
+	Tty         bool
+	User        string
+	WorkDir     string
+}
diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index 025da50f3..262945cd7 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -8,10 +8,12 @@ import (
 )
 
 type ContainerEngine interface {
+	ContainerAttach(ctx context.Context, nameOrId string, options AttachOptions) error
 	ContainerCommit(ctx context.Context, nameOrId string, options CommitOptions) (*CommitReport, error)
 	ContainerCheckpoint(ctx context.Context, namesOrIds []string, options CheckpointOptions) ([]*CheckpointReport, error)
 	ContainerRestore(ctx context.Context, namesOrIds []string, options RestoreOptions) ([]*RestoreReport, error)
 	ContainerCreate(ctx context.Context, s *specgen.SpecGenerator) (*ContainerCreateReport, error)
+	ContainerExec(ctx context.Context, nameOrId string, options ExecOptions) (int, error)
 	ContainerExists(ctx context.Context, nameOrId string) (*BoolReport, error)
 	ContainerInspect(ctx context.Context, namesOrIds []string, options InspectOptions) ([]*ContainerInspectReport, error)
 	ContainerExport(ctx context.Context, nameOrId string, options ContainerExportOptions) error
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")
+}