Refactor exec interface (#578)

This removes the dependence on remotecommand in providers as well as the
need to expose provider ID's for the sake of the ExecInContainer API.

providers/mock/mock.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"math/rand"
 	"time"
@@ -16,8 +15,6 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/types"
-	"k8s.io/client-go/tools/remotecommand"
 	stats "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
 
 	"github.com/virtual-kubelet/virtual-kubelet/providers"
@@ -215,9 +212,9 @@ func (p *MockProvider) GetPodFullName(namespace string, pod string) string {
 	return ""
 }
 
-// ExecInContainer executes a command in a container in the pod, copying data
+// RunInContainer executes a command in a container in the pod, copying data
 // between in/out/err and the container's stdin/stdout/stderr.
-func (p *MockProvider) ExecInContainer(name string, uid types.UID, container string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool, resize <-chan remotecommand.TerminalSize, timeout time.Duration) error {
+func (p *MockProvider) RunInContainer(ctx context.Context, namespace, name, container string, cmd []string, attach providers.AttachIO) error {
 	log.G(context.TODO()).Info("receive ExecInContainer %q", container)
 	return nil
 }