Add latest to wait

It is desirable to have a --latest switch on the podman wait
command so we can wait on the latest container created to end.

Also, fixes a panic with latest where no containers are available.

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

Closes: #201
Approved by: baude

1 files changed, 12 insertions, 3 deletions

diff --git a/cmd/podman/wait.go b/cmd/podman/wait.go
index 27cfecac9..2b2a07738 100644
--- a/cmd/podman/wait.go
+++ b/cmd/podman/wait.go
@@ -14,11 +14,12 @@ var (
 
 	Block until one or more containers stop and then print their exit codes
 `
-
+	waitFlags   = []cli.Flag{LatestFlag}
 	waitCommand = cli.Command{
 		Name:        "wait",
 		Usage:       "Block on one or more containers",
 		Description: waitDescription,
+		Flags:       waitFlags,
 		Action:      waitCmd,
 		ArgsUsage:   "CONTAINER-NAME [CONTAINER-NAME ...]",
 	}
@@ -26,7 +27,7 @@ var (
 
 func waitCmd(c *cli.Context) error {
 	args := c.Args()
-	if len(args) < 1 {
+	if len(args) < 1 && !c.Bool("latest") {
 		return errors.Errorf("you must provide at least one container name or id")
 	}
 
@@ -41,7 +42,15 @@ func waitCmd(c *cli.Context) error {
 	}
 
 	var lastError error
-	for _, container := range c.Args() {
+	if c.Bool("latest") {
+		latestCtr, err := runtime.GetLatestContainer()
+		if err != nil {
+			return errors.Wrapf(err, "unable to wait on latest container")
+		}
+		args = append(args, latestCtr.ID())
+	}
+
+	for _, container := range args {
 		ctr, err := runtime.LookupContainer(container)
 		if err != nil {
 			return errors.Wrapf(err, "unable to find container %s", container)