Add kpod wait

Waits on one or more containers to stop and prints the container's
return code

Signed-off-by: baude <bbaude@redhat.com>

libkpod/wait.go

@@ -0,0 +1,42 @@
+package libkpod
+
+import (
+	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/pkg/errors"
+	"k8s.io/apimachinery/pkg/util/wait"
+)
+
+func isStopped(c *ContainerServer, ctr *oci.Container) bool {
+	c.runtime.UpdateStatus(ctr)
+	cStatus := c.runtime.ContainerStatus(ctr)
+	if cStatus.Status == oci.ContainerStateStopped {
+		return true
+	}
+	return false
+}
+
+// ContainerWait stops a running container with a grace period (i.e., timeout).
+func (c *ContainerServer) ContainerWait(container string) (int32, error) {
+	ctr, err := c.LookupContainer(container)
+	if err != nil {
+		return 0, errors.Wrapf(err, "failed to find container %s", container)
+	}
+
+	err = wait.PollImmediateInfinite(1,
+		func() (bool, error) {
+			if !isStopped(c, ctr) {
+				return false, nil
+			} else { // nolint
+				return true, nil // nolint
+			} // nolint
+
+		},
+	)
+
+	if err != nil {
+		return 0, err
+	}
+	exitCode := ctr.State().ExitCode
+	c.ContainerStateToDisk(ctr)
+	return exitCode, nil
+}