Add --namespace flag to Podman

Allows joining libpod to a specific namespace when running a
Podman command.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

cmd/podman/libpodruntime/runtime.go

@@ -88,6 +88,10 @@ func GetRuntimeWithStorageOpts(c *cli.Context, storageOpts *storage.StoreOptions
 	// TODO CLI flags for image config?
 	// TODO CLI flag for signature policy?
 
+	if c.GlobalIsSet("namespace") {
+		options = append(options, libpod.WithNamespace(c.GlobalString("namespace")))
+	}
+
 	if c.GlobalIsSet("runtime") {
 		options = append(options, libpod.WithOCIRuntime(c.GlobalString("runtime")))
 	}

cmd/podman/main.go

@@ -172,6 +172,11 @@ func main() {
 			Usage: "log messages above specified level: debug, info, warn, error (default), fatal or panic",
 			Value: "error",
 		},
+		cli.StringFlag{
+			Name:  "namespace",
+			Usage: "set the libpod namespace, used create separate views of the containers and pods on the system",
+			Value: "",
+		},
 		cli.StringFlag{
 			Name:  "root",
 			Usage: "path to the root directory in which data, including images, is stored",

completions/bash/podman

@@ -2224,6 +2224,7 @@ _podman_podman() {
            --storage-driver
            --storage-opt
            --log-level
+           --namespace
     "
      local boolean_options="
            --help -h

docs/podman.1.md

@@ -39,6 +39,11 @@ Path to where the cpu performance results should be written
 
 log messages above specified level: debug, info, warn, error (default), fatal or panic
 
+**--namespace**
+
+set namespace libpod namespace. Namespaces are used to separate groups of containers and pods in libpod's state.
+When namespace is set, created containers and pods will join the given namespace, and only containers and pods in the given namespace will be visible to Podman.
+
 **--root**=**value**
 
 Path to the root directory in which data, including images, is stored

libpod/options.go

@@ -285,7 +285,6 @@ func WithCNIPluginDir(dir string) RuntimeOption {
 }
 
 // WithNamespace sets the namespace for libpod.
-// Namespace is the libpod namespace to use.
 // Namespaces are used to create scopes to separate containers and pods
 // in the state.
 // When namespace is set, libpod will only view containers and pods in