Implement conmon exec

This includes:
	Implement exec -i and fix some typos in description of -i docs
	pass failed runtime status to caller
	Add resize handling for a terminal connection
	Customize exec systemd-cgroup slice
	fix healthcheck
	fix top
	add --detach-keys
	Implement podman-remote exec (jhonce)
	* Cleanup some orphaned code (jhonce)
	adapt remote exec for conmon exec (pehunt)
	Fix healthcheck and exec to match docs
		Introduce two new OCIRuntime errors to more comprehensively describe situations in which the runtime can error
		Use these different errors in branching for exit code in healthcheck and exec
	Set conmon to use new api version

Signed-off-by: Jhon Honce <jhonce@redhat.com>

Signed-off-by: Peter Hunt <pehunt@redhat.com>

3 files changed, 105 insertions, 5 deletions

diff --git a/pkg/varlinkapi/attach.go b/pkg/varlinkapi/attach.go
index afa88e6a3..97ba525a5 100644
--- a/pkg/varlinkapi/attach.go
+++ b/pkg/varlinkapi/attach.go
@@ -82,9 +82,10 @@ func (i *LibpodAPI) Attach(call iopodman.VarlinkCall, name string, detachKeys st
 	if finalErr != define.ErrDetach && finalErr != nil {
 		logrus.Error(finalErr)
 	}
-	quitWriter := virtwriter.NewVirtWriteCloser(writer, virtwriter.Quit)
-	_, err = quitWriter.Write([]byte("HANG-UP"))
-	// TODO error handling is not quite right here yet
+
+	if err = virtwriter.HangUp(writer); err != nil {
+		logrus.Errorf("Failed to HANG-UP attach to %s: %s", ctr.ID(), err.Error())
+	}
 	return call.Writer.Flush()
 }
 
diff --git a/pkg/varlinkapi/containers.go b/pkg/varlinkapi/containers.go
index 6f6909fac..19a8bfd2e 100644
--- a/pkg/varlinkapi/containers.go
+++ b/pkg/varlinkapi/containers.go
@@ -19,8 +19,11 @@ import (
 	"github.com/containers/libpod/libpod/define"
 	"github.com/containers/libpod/libpod/logs"
 	"github.com/containers/libpod/pkg/adapter/shortcuts"
+	"github.com/containers/libpod/pkg/varlinkapi/virtwriter"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"k8s.io/client-go/tools/remotecommand"
 )
 
 // ListContainers ...
@@ -756,3 +759,82 @@ func (i *LibpodAPI) Top(call iopodman.VarlinkCall, nameOrID string, descriptors
 	}
 	return call.ReplyTop(topInfo)
 }
+
+// ExecContainer is the varlink endpoint to execute a command in a container
+func (i *LibpodAPI) ExecContainer(call iopodman.VarlinkCall, opts iopodman.ExecOpts) error {
+	if !call.WantsUpgrade() {
+		return call.ReplyErrorOccurred("client must use upgraded connection to exec")
+	}
+
+	ctr, err := i.Runtime.LookupContainer(opts.Name)
+	if err != nil {
+		return call.ReplyContainerNotFound(opts.Name, err.Error())
+	}
+
+	state, err := ctr.State()
+	if err != nil {
+		return call.ReplyErrorOccurred(
+			fmt.Sprintf("exec failed to obtain container %s state: %s", ctr.ID(), err.Error()))
+	}
+
+	if state != define.ContainerStateRunning {
+		return call.ReplyErrorOccurred(
+			fmt.Sprintf("exec requires a running container, %s is %s", ctr.ID(), state.String()))
+	}
+
+	envs := []string{}
+	if opts.Env != nil {
+		envs = *opts.Env
+	}
+
+	var user string
+	if opts.User != nil {
+		user = *opts.User
+	}
+
+	var workDir string
+	if opts.Workdir != nil {
+		workDir = *opts.Workdir
+	}
+
+	resizeChan := make(chan remotecommand.TerminalSize)
+	errChan := make(chan error)
+
+	reader, writer, _, pipeWriter, streams := setupStreams(call)
+
+	go func() {
+		fmt.Printf("ExecContainer Start Reader\n")
+		if err := virtwriter.Reader(reader, nil, nil, pipeWriter, resizeChan); err != nil {
+			fmt.Printf("ExecContainer Reader err %s, %s\n", err.Error(), errors.Cause(err).Error())
+			errChan <- err
+		}
+	}()
+
+	// Debugging...
+	time.Sleep(5 * time.Second)
+
+	go func() {
+		fmt.Printf("ExecContainer Start ctr.Exec\n")
+		// TODO detach keys and resize
+		// TODO add handling for exit code
+		// TODO capture exit code and return to main thread
+		_, err := ctr.Exec(opts.Tty, opts.Privileged, envs, opts.Cmd, user, workDir, streams, 0, nil, "")
+		if err != nil {
+			fmt.Printf("ExecContainer Exec err %s, %s\n", err.Error(), errors.Cause(err).Error())
+			errChan <- errors.Wrapf(err, "ExecContainer failed for container %s", ctr.ID())
+		}
+	}()
+
+	execErr := <-errChan
+
+	if execErr != nil && errors.Cause(execErr) != io.EOF {
+		fmt.Printf("ExecContainer err: %s\n", execErr.Error())
+		return call.ReplyErrorOccurred(execErr.Error())
+	}
+
+	if err = virtwriter.HangUp(writer); err != nil {
+		fmt.Printf("ExecContainer hangup err: %s\n", err.Error())
+		logrus.Errorf("ExecContainer failed to HANG-UP on %s: %s", ctr.ID(), err.Error())
+	}
+	return call.Writer.Flush()
+}
diff --git a/pkg/varlinkapi/virtwriter/virtwriter.go b/pkg/varlinkapi/virtwriter/virtwriter.go
index 5e88914b2..0da2a91fc 100644
--- a/pkg/varlinkapi/virtwriter/virtwriter.go
+++ b/pkg/varlinkapi/virtwriter/virtwriter.go
@@ -4,8 +4,9 @@ import (
 	"bufio"
 	"encoding/binary"
 	"encoding/json"
-	"errors"
 	"io"
+
+	"github.com/pkg/errors"
 	"k8s.io/client-go/tools/remotecommand"
 )
 
@@ -95,7 +96,7 @@ func Reader(r *bufio.Reader, output io.Writer, errput io.Writer, input io.Writer
 	for {
 		n, err := io.ReadFull(r, headerBytes)
 		if err != nil {
-			return err
+			return errors.Wrapf(err, "Virtual Read failed, %d", n)
 		}
 		if n < 8 {
 			return errors.New("short read and no full header read")
@@ -151,3 +152,19 @@ func Reader(r *bufio.Reader, output io.Writer, errput io.Writer, input io.Writer
 		}
 	}
 }
+
+// HangUp sends message to peer to close connection
+func HangUp(writer *bufio.Writer) (err error) {
+	n := 0
+	msg := []byte("HANG-UP")
+
+	writeQuit := NewVirtWriteCloser(writer, Quit)
+	if n, err = writeQuit.Write(msg); err != nil {
+		return
+	}
+
+	if n != len(msg) {
+		return errors.Errorf("Failed to send complete %s message", string(msg))
+	}
+	return
+}