Add unshare to podman

This command lets the user run a command in a new user namespace like `unshare -u`.
It uses the implementation of unshare in buildah. ( fixes #1388 )

Signed-off-by: Divyansh Kamboj <kambojdivyansh2000@gmail.com>

6 files changed, 280 insertions, 134 deletions

diff --git a/cmd/podman/commands.go b/cmd/podman/commands.go
index 3a409f503..2ac465b9d 100644
--- a/cmd/podman/commands.go
+++ b/cmd/podman/commands.go
@@ -20,6 +20,7 @@ func getMainCommands() []*cobra.Command {
 		_refreshCommand,
 		_searchCommand,
 		_statsCommand,
+		_unshareCommand,
 	}
 
 	if len(_varlinkCommand.Use) > 0 {
diff --git a/cmd/podman/unshare.go b/cmd/podman/unshare.go
new file mode 100644
index 000000000..1db647dba
--- /dev/null
+++ b/cmd/podman/unshare.go
@@ -0,0 +1,54 @@
+// +build linux
+
+package main
+
+import (
+	"os"
+	"os/exec"
+
+	"github.com/containers/buildah/pkg/unshare"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+var (
+	unshareDescription = "Runs a command in a modified user namespace."
+	_unshareCommand    = &cobra.Command{
+		Use:   "unshare [flags] [COMMAND [ARG]]",
+		Short: "Run a command in a modified user namespace",
+		Long:  unshareDescription,
+		RunE:  unshareCmd,
+		Example: `podman unshare id
+  podman unshare cat /proc/self/uid_map,
+  podman unshare podman-script.sh`,
+	}
+)
+
+func init() {
+	_unshareCommand.SetUsageTemplate(UsageTemplate())
+	flags := _unshareCommand.Flags()
+	flags.SetInterspersed(false)
+}
+
+// unshareCmd execs whatever using the ID mappings that we want to use for ourselves
+func unshareCmd(c *cobra.Command, args []string) error {
+	if isRootless := unshare.IsRootless(); !isRootless {
+		return errors.Errorf("please use unshare with rootless")
+	}
+	// exec the specified command, if there is one
+	if len(args) < 1 {
+		// try to exec the shell, if one's set
+		shell, shellSet := os.LookupEnv("SHELL")
+		if !shellSet {
+			return errors.Errorf("no command specified and no $SHELL specified")
+		}
+		args = []string{shell}
+	}
+	cmd := exec.Command(args[0], args[1:]...)
+	cmd.Env = unshare.RootlessEnv()
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	unshare.ExecRunnable(cmd)
+	return nil
+}
diff --git a/commands.md b/commands.md
index e6c211254..d3ceca9dc 100644
--- a/commands.md
+++ b/commands.md
@@ -4,85 +4,86 @@
 
 ## Podman Commands
 
-Command                                                                  | Description                                                                | Demo    | Script
-:----------------------------------------------------------------------- | :------------------------------------------------------------------------- | :-------------------------------------------------------------------------- | :--------------------------------------------------------------------------
-[podman(1)](/docs/podman.1.md)                                           | Simple management tool for pods and images                                 |
-[podman-attach(1)](/docs/podman-attach.1.md)                             | Attach to a running container                                              |
-[podman-build(1)](/docs/podman-build.1.md)                               | Build an image using instructions from Dockerfiles                         |
-[podman-commit(1)](/docs/podman-commit.1.md)                             | Create new image based on the changed container                            |
-[podman-container(1)](/docs/podman-container.1.md)                       | Manage Containers                                                          |
-[podman-container-checkpoint(1)](/docs/podman-container-checkpoint.1.md) | Checkpoints one or more running containers                                 |
-[podman-container-cleanup(1)](/docs/podman-container-cleanup.1.md)       | Cleanup Container storage and networks                                     |
-[podman-container-exists(1)](/docs/podman-container-exists.1.md)         | Check if an container exists in local storage                              |
-[podman-container-prune(1)](/docs/podman-container-prune.1.md)           | Remove all stopped containers                                              |
-[podman-container-refresh(1)](/docs/podman-container-refresh.1.md)       | Refresh all containers state in database                                   |
-[podman-container-restore(1)](/docs/podman-container-restore.1.md)       | Restores one or more running containers                                    |
-[podman-container-runlabel(1)](/docs/podman-container-runlabel.1.md)     | Execute Image Label Method                                                 |
-[podman-cp(1)](/docs/podman-cp.1.md)                                     | Copy files/folders between a container and the local filesystem            |
-[podman-create(1)](/docs/podman-create.1.md)                             | Create a new container                                                     |
-[podman-diff(1)](/docs/podman-diff.1.md)                                 | Inspect changes on a container or image's filesystem                       |
-[podman-events(1)](/docs/podman-events.1.md)                             | Monitor Podman events                                                      |
-[podman-exec(1)](/docs/podman-exec.1.md)                                 | Execute a command in a running container                                   |
-[podman-export(1)](/docs/podman-export.1.md)                             | Export container's filesystem contents as a tar archive                    |
-[podman-generate(1)](/docs/podman-generate.1.md)                         | Generate structured output based on Podman containers and pods             |
-[podman-generate-kube(1)](/docs/podman-generate-kube.1.md)               | Generate Kubernetes YAML based on a container or Pod             |
-[podman-generate-systemd(1)](/docs/podman-generate-systemd.1.md)         | Generate a Systemd unit file for a container             |
-[podman-history(1)](/docs/podman-history.1.md)                           | Shows the history of an image                                              |
-[podman-image(1)](/docs/podman-image.1.md)                               | Manage Images                                                              |
-[podman-image-exists(1)](/docs/podman-image-exists.1.md)                 | Check if an image exists in local storage                                  |
-[podman-image-prune(1)](/docs/podman-image-prune.1.md)                   | Remove all unused images                                                   |
-[podman-image-sign(1)](/docs/podman-image-sign.1.md)                     | Create a signature for an image                                            |
-[podman-image-trust(1)](/docs/podman-image-trust.1.md)                   | Manage container registry image trust policy                               |
-[podman-images(1)](/docs/podman-images.1.md)                             | List images in local storage                                               | [![...](/docs/play.png)](https://podman.io/asciinema/podman/images/) | [Here](https://github.com/containers/Demos/blob/master/podman_cli/podman_images.sh)
-[podman-import(1)](/docs/podman-import.1.md)                             | Import a tarball and save it as a filesystem image                         |
-[podman-info(1)](/docs/podman-info.1.md)                                 | Display system information                                                 |
-[podman-init(1)](/docs/podman-init.1.md)                                 | Initialize a container                                                     |
-[podman-inspect(1)](/docs/podman-inspect.1.md)                           | Display the configuration of a container or image                          | [![...](/docs/play.png)](https://asciinema.org/a/133418)
-[podman-kill(1)](/docs/podman-kill.1.md)                                 | Kill the main process in one or more running containers                    |
-[podman-load(1)](/docs/podman-load.1.md)                                 | Load an image from a container image archive                               |
-[podman-login(1)](/docs/podman-login.1.md)                               | Login to a container registry                                              |
-[podman-logout(1)](/docs/podman-logout.1.md)                             | Logout of a container registry                                             |
-[podman-logs(1)](/docs/podman-logs.1.md)                                 | Display the logs of a container                                            |
-[podman-mount(1)](/docs/podman-mount.1.md)                               | Mount a working container's root filesystem                                |
-[podman-pause(1)](/docs/podman-pause.1.md)                               | Pause one or more running containers                                       | [![...](/docs/play.png)](https://asciinema.org/a/141292)
-[podman-play(1)](/docs/podman-play.1.md)                                 | Play pods and containers based on a structured input file                  |
-[podman-pod(1)](/docs/podman-pod.1.md)                                   | Simple management tool for groups of containers, called pods               |
-[podman-pod-create(1)](/docs/podman-pod-create.1.md)                     | Create a new pod                                                           |
-[podman-pod-inspect(1)](/docs/podman-pod-inspect.1.md)                   | Inspect a pod                                                              |
-[podman-pod-kill(1)](podman-pod-kill.1.md)                               | Kill the main process of each container in pod.                            |
-[podman-pod-ps(1)](/docs/podman-pod-ps.1.md)                             | List the pods on the system                                                |
-[podman-pod-pause(1)](podman-pod-pause.1.md)                             | Pause one or more pods.                                                    |
-[podman-pod-restart](/docs/podman-pod-restart.1.md)                      | Restart one or more pods                                                   |
-[podman-pod-rm(1)](/docs/podman-pod-rm.1.md)                             | Remove one or more pods                                                    |
-[podman-pod-start(1)](/docs/podman-pod-start.1.md)                       | Start one or more pods                                                     |
-[podman-pod-stats(1)](/docs/podman-pod-stats.1.md)                       | Display a live stream of one or more pods' resource usage statistics       |                                                                             |  |
-[podman-pod-stop(1)](/docs/podman-pod-stop.1.md)                         | Stop one or more pods                                                      |
-[podman-pod-top(1)](/docs/podman-pod-top.1.md)                           | Display the running processes of a pod                                     |
-[podman-pod-unpause(1)](podman-pod-unpause.1.md)                         | Unpause one or more pods.                                                  |
-[podman-port(1)](/docs/podman-port.1.md)                                 | List port mappings for running containers                                  |
-[podman-ps(1)](/docs/podman-ps.1.md)                                     | Prints out information about containers                                    |
-[podman-pull(1)](/docs/podman-pull.1.md)                                 | Pull an image from a registry                                              |
-[podman-push(1)](/docs/podman-push.1.md)                                 | Push an image to a specified destination                                   | [![...](/docs/play.png)](https://asciinema.org/a/133276)
-[podman-restart](/docs/podman-restart.1.md)                              | Restarts one or more containers                                            | [![...](/docs/play.png)](https://asciinema.org/a/jiqxJAxcVXw604xdzMLTkQvHM)
-[podman-rm(1)](/docs/podman-rm.1.md)                                     | Removes one or more containers                                             |
-[podman-rmi(1)](/docs/podman-rmi.1.md)                                   | Removes one or more images                                                 |
-[podman-run(1)](/docs/podman-run.1.md)                                   | Run a command in a container                                               |
-[podman-save(1)](/docs/podman-save.1.md)                                 | Saves an image to an archive                                               |
-[podman-search(1)](/docs/podman-search.1.md)                             | Search a registry for an image                                             |
-[podman-start(1)](/docs/podman-start.1.md)                               | Starts one or more containers                                              |
-[podman-stats(1)](/docs/podman-stats.1.md)                               | Display a live stream of one or more containers' resource usage statistics |
-[podman-stop(1)](/docs/podman-stop.1.md)                                 | Stops one or more running containers                                       |
-[podman-system(1)](/docs/podman-system.1.md)                             | Manage podman                                                              |
-[podman-tag(1)](/docs/podman-tag.1.md)                                   | Add an additional name to a local image                                    | [![...](/docs/play.png)](https://asciinema.org/a/133803)
-[podman-top(1)](/docs/podman-top.1.md)                                   | Display the running processes of a container                               |
-[podman-umount(1)](/docs/podman-umount.1.md)                             | Unmount a working container's root filesystem                              |
-[podman-unpause(1)](/docs/podman-unpause.1.md)                           | Unpause one or more running containers                                     | [![...](/docs/play.png)](https://asciinema.org/a/141292)
-[podman-varlink(1)](/docs/podman-varlink.1.md)                           | Run the varlink backend                                                    |
-[podman-version(1)](/docs/podman-version.1.md)                           | Display the version information                                            |
-[podman-volume(1)](/docs/podman-volume.1.md)                             | Manage Volumes                                                             |
-[podman-volume-create(1)](/docs/podman-volume-create.1.md)               | Create a volume                                                            |
-[podman-volume-inspect(1)](/docs/podman-volume-inspect.1.md)             | Get detailed information on one or more volumes                            |
-[podman-volume-ls(1)](/docs/podman-volume-ls.1.md)                       | List all the available volumes                                             |
-[podman-volume-rm(1)](/docs/podman-volume-rm.1.md)                       | Remove one or more volumes                                                 |
-[podman-volume-prune(1)](/docs/podman-volume-prune.1.md)                 | Remove all unused volumes                                                  |
-[podman-wait(1)](/docs/podman-wait.1.md)                                 | Wait on one or more containers to stop and print their exit codes
+| Command                                                                  | Description                                                                | Demo                                                                        | Script                                                                              |
+| :----------------------------------------------------------------------- | :------------------------------------------------------------------------- | :-------------------------------------------------------------------------- | :---------------------------------------------------------------------------------- |
+| [podman(1)](/docs/podman.1.md)                                           | Simple management tool for pods and images                                 |
+| [podman-attach(1)](/docs/podman-attach.1.md)                             | Attach to a running container                                              |
+| [podman-build(1)](/docs/podman-build.1.md)                               | Build an image using instructions from Dockerfiles                         |
+| [podman-commit(1)](/docs/podman-commit.1.md)                             | Create new image based on the changed container                            |
+| [podman-container(1)](/docs/podman-container.1.md)                       | Manage Containers                                                          |
+| [podman-container-checkpoint(1)](/docs/podman-container-checkpoint.1.md) | Checkpoints one or more running containers                                 |
+| [podman-container-cleanup(1)](/docs/podman-container-cleanup.1.md)       | Cleanup Container storage and networks                                     |
+| [podman-container-exists(1)](/docs/podman-container-exists.1.md)         | Check if an container exists in local storage                              |
+| [podman-container-prune(1)](/docs/podman-container-prune.1.md)           | Remove all stopped containers                                              |
+| [podman-container-refresh(1)](/docs/podman-container-refresh.1.md)       | Refresh all containers state in database                                   |
+| [podman-container-restore(1)](/docs/podman-container-restore.1.md)       | Restores one or more running containers                                    |
+| [podman-container-runlabel(1)](/docs/podman-container-runlabel.1.md)     | Execute Image Label Method                                                 |
+| [podman-cp(1)](/docs/podman-cp.1.md)                                     | Copy files/folders between a container and the local filesystem            |
+| [podman-create(1)](/docs/podman-create.1.md)                             | Create a new container                                                     |
+| [podman-diff(1)](/docs/podman-diff.1.md)                                 | Inspect changes on a container or image's filesystem                       |
+| [podman-events(1)](/docs/podman-events.1.md)                             | Monitor Podman events                                                      |
+| [podman-exec(1)](/docs/podman-exec.1.md)                                 | Execute a command in a running container                                   |
+| [podman-export(1)](/docs/podman-export.1.md)                             | Export container's filesystem contents as a tar archive                    |
+| [podman-generate(1)](/docs/podman-generate.1.md)                         | Generate structured output based on Podman containers and pods             |
+| [podman-generate-kube(1)](/docs/podman-generate-kube.1.md)               | Generate Kubernetes YAML based on a container or Pod                       |
+| [podman-generate-systemd(1)](/docs/podman-generate-systemd.1.md)         | Generate a Systemd unit file for a container                               |
+| [podman-history(1)](/docs/podman-history.1.md)                           | Shows the history of an image                                              |
+| [podman-image(1)](/docs/podman-image.1.md)                               | Manage Images                                                              |
+| [podman-image-exists(1)](/docs/podman-image-exists.1.md)                 | Check if an image exists in local storage                                  |
+| [podman-image-prune(1)](/docs/podman-image-prune.1.md)                   | Remove all unused images                                                   |
+| [podman-image-sign(1)](/docs/podman-image-sign.1.md)                     | Create a signature for an image                                            |
+| [podman-image-trust(1)](/docs/podman-image-trust.1.md)                   | Manage container registry image trust policy                               |
+| [podman-images(1)](/docs/podman-images.1.md)                             | List images in local storage                                               | [![...](/docs/play.png)](https://podman.io/asciinema/podman/images/)        | [Here](https://github.com/containers/Demos/blob/master/podman_cli/podman_images.sh) |
+| [podman-import(1)](/docs/podman-import.1.md)                             | Import a tarball and save it as a filesystem image                         |
+| [podman-info(1)](/docs/podman-info.1.md)                                 | Display system information                                                 |
+| [podman-init(1)](/docs/podman-init.1.md)                                 | Initialize a container                                                     |
+| [podman-inspect(1)](/docs/podman-inspect.1.md)                           | Display the configuration of a container or image                          | [![...](/docs/play.png)](https://asciinema.org/a/133418)                    |
+| [podman-kill(1)](/docs/podman-kill.1.md)                                 | Kill the main process in one or more running containers                    |
+| [podman-load(1)](/docs/podman-load.1.md)                                 | Load an image from a container image archive                               |
+| [podman-login(1)](/docs/podman-login.1.md)                               | Login to a container registry                                              |
+| [podman-logout(1)](/docs/podman-logout.1.md)                             | Logout of a container registry                                             |
+| [podman-logs(1)](/docs/podman-logs.1.md)                                 | Display the logs of a container                                            |
+| [podman-mount(1)](/docs/podman-mount.1.md)                               | Mount a working container's root filesystem                                |
+| [podman-pause(1)](/docs/podman-pause.1.md)                               | Pause one or more running containers                                       | [![...](/docs/play.png)](https://asciinema.org/a/141292)                    |
+| [podman-play(1)](/docs/podman-play.1.md)                                 | Play pods and containers based on a structured input file                  |
+| [podman-pod(1)](/docs/podman-pod.1.md)                                   | Simple management tool for groups of containers, called pods               |
+| [podman-pod-create(1)](/docs/podman-pod-create.1.md)                     | Create a new pod                                                           |
+| [podman-pod-inspect(1)](/docs/podman-pod-inspect.1.md)                   | Inspect a pod                                                              |
+| [podman-pod-kill(1)](podman-pod-kill.1.md)                               | Kill the main process of each container in pod.                            |
+| [podman-pod-ps(1)](/docs/podman-pod-ps.1.md)                             | List the pods on the system                                                |
+| [podman-pod-pause(1)](podman-pod-pause.1.md)                             | Pause one or more pods.                                                    |
+| [podman-pod-restart](/docs/podman-pod-restart.1.md)                      | Restart one or more pods                                                   |
+| [podman-pod-rm(1)](/docs/podman-pod-rm.1.md)                             | Remove one or more pods                                                    |
+| [podman-pod-start(1)](/docs/podman-pod-start.1.md)                       | Start one or more pods                                                     |
+| [podman-pod-stats(1)](/docs/podman-pod-stats.1.md)                       | Display a live stream of one or more pods' resource usage statistics       |                                                                             |                                                                                     |
+| [podman-pod-stop(1)](/docs/podman-pod-stop.1.md)                         | Stop one or more pods                                                      |
+| [podman-pod-top(1)](/docs/podman-pod-top.1.md)                           | Display the running processes of a pod                                     |
+| [podman-pod-unpause(1)](podman-pod-unpause.1.md)                         | Unpause one or more pods.                                                  |
+| [podman-port(1)](/docs/podman-port.1.md)                                 | List port mappings for running containers                                  |
+| [podman-ps(1)](/docs/podman-ps.1.md)                                     | Prints out information about containers                                    |
+| [podman-pull(1)](/docs/podman-pull.1.md)                                 | Pull an image from a registry                                              |
+| [podman-push(1)](/docs/podman-push.1.md)                                 | Push an image to a specified destination                                   | [![...](/docs/play.png)](https://asciinema.org/a/133276)                    |
+| [podman-restart](/docs/podman-restart.1.md)                              | Restarts one or more containers                                            | [![...](/docs/play.png)](https://asciinema.org/a/jiqxJAxcVXw604xdzMLTkQvHM) |
+| [podman-rm(1)](/docs/podman-rm.1.md)                                     | Removes one or more containers                                             |
+| [podman-rmi(1)](/docs/podman-rmi.1.md)                                   | Removes one or more images                                                 |
+| [podman-run(1)](/docs/podman-run.1.md)                                   | Run a command in a container                                               |
+| [podman-save(1)](/docs/podman-save.1.md)                                 | Saves an image to an archive                                               |
+| [podman-search(1)](/docs/podman-search.1.md)                             | Search a registry for an image                                             |
+| [podman-start(1)](/docs/podman-start.1.md)                               | Starts one or more containers                                              |
+| [podman-stats(1)](/docs/podman-stats.1.md)                               | Display a live stream of one or more containers' resource usage statistics |
+| [podman-stop(1)](/docs/podman-stop.1.md)                                 | Stops one or more running containers                                       |
+| [podman-system(1)](/docs/podman-system.1.md)                             | Manage podman                                                              |
+| [podman-tag(1)](/docs/podman-tag.1.md)                                   | Add an additional name to a local image                                    | [![...](/docs/play.png)](https://asciinema.org/a/133803)                    |
+| [podman-top(1)](/docs/podman-top.1.md)                                   | Display the running processes of a container                               |
+| [podman-umount(1)](/docs/podman-umount.1.md)                             | Unmount a working container's root filesystem                              |
+| [podman-unpause(1)](/docs/podman-unpause.1.md)                           | Unpause one or more running containers                                     | [![...](/docs/play.png)](https://asciinema.org/a/141292)                    |
+| [podman-unshare(1)](/docs/podman-unshare.1.md)                           | Run a command inside of a modified user namespace.                         |
+| [podman-varlink(1)](/docs/podman-varlink.1.md)                           | Run the varlink backend                                                    |
+| [podman-version(1)](/docs/podman-version.1.md)                           | Display the version information                                            |
+| [podman-volume(1)](/docs/podman-volume.1.md)                             | Manage Volumes                                                             |
+| [podman-volume-create(1)](/docs/podman-volume-create.1.md)               | Create a volume                                                            |
+| [podman-volume-inspect(1)](/docs/podman-volume-inspect.1.md)             | Get detailed information on one or more volumes                            |
+| [podman-volume-ls(1)](/docs/podman-volume-ls.1.md)                       | List all the available volumes                                             |
+| [podman-volume-rm(1)](/docs/podman-volume-rm.1.md)                       | Remove one or more volumes                                                 |
+| [podman-volume-prune(1)](/docs/podman-volume-prune.1.md)                 | Remove all unused volumes                                                  |
+| [podman-wait(1)](/docs/podman-wait.1.md)                                 | Wait on one or more containers to stop and print their exit codes          |
diff --git a/docs/podman-unshare.1.md b/docs/podman-unshare.1.md
new file mode 100644
index 000000000..a7f018ce1
--- /dev/null
+++ b/docs/podman-unshare.1.md
@@ -0,0 +1,37 @@
+% podman-unshare "1"
+
+## NAME
+podman\-unshare - Run a command inside of a modified user namespace.
+
+## SYNOPSIS
+**podman unshare** [*options*] [**--**] [*command*]
+
+## DESCRIPTION
+Launches a process (by default, *$SHELL*) in a new user namespace. The user
+namespace is configured so that the invoking user's UID and primary GID appear
+to be UID 0 and GID 0, respectively.  Any ranges which match that user and
+group in /etc/subuid and /etc/subgid are also mapped in as themselves with the
+help of the *newuidmap(1)* and *newgidmap(1)* helpers.
+
+podman unshare is useful for troubleshooting unprivileged operations and for
+manually clearing storage and other data related to images and containers.
+
+It is also useful if you want to use the `podman mount` command.  If an unprivileged users wants to mount and work with a container, then they need to execute
+podman unshare.  Executing `podman mount` fails for unprivileged users unless the user is running inside a `podman unshare` session.
+
+## EXAMPLE
+
+```
+$ podman unshare id
+uid=0(root) gid=0(root) groups=0(root),65534(nobody)
+
+$ podman unshare cat /proc/self/uid_map /proc/self/gid_map
+         0       1000          1
+         1      10000      65536
+         0       1000          1
+         1      10000      65536
+```
+
+
+## SEE ALSO
+podman(1), podman-mount(1), namespaces(7), newuidmap(1), newgidmap(1), user\_namespaces(7)
\ No newline at end of file
diff --git a/docs/podman.1.md b/docs/podman.1.md
index ef12cf1cc..ff942a3c4 100644
--- a/docs/podman.1.md
+++ b/docs/podman.1.md
@@ -128,58 +128,59 @@ the exit codes follow the `chroot` standard, see below:
 
 ## COMMANDS
 
-| Command                                   | Description                                                                    |
-| ----------------------------------------- | ------------------------------------------------------------------------------ |
-| [podman-attach(1)](podman-attach.1.md)    | Attach to a running container.                                                 |
-| [podman-build(1)](podman-build.1.md)      | Build a container image using a Dockerfile.                                    |
-| [podman-commit(1)](podman-commit.1.md)    | Create new image based on the changed container.                               |
-| [podman-container(1)](podman-container.1.md)    | Manage containers.                                                       |
-| [podman-cp(1)](podman-cp.1.md)            | Copy files/folders between a container and the local filesystem.               |
-| [podman-create(1)](podman-create.1.md)    | Create a new container.                                                        |
-| [podman-diff(1)](podman-diff.1.md)        | Inspect changes on a container or image's filesystem.                          |
-| [podman-events(1)](podman-events.1.md)    | Monitor Podman events                                                          |
-| [podman-exec(1)](podman-exec.1.md)        | Execute a command in a running container.                                      |
-| [podman-export(1)](podman-export.1.md)    | Export a container's filesystem contents as a tar archive.                     |
-| [podman-generate(1)](podman-generate.1.md)| Generate structured data based for a containers and pods.                      |
-| [podman-healthcheck(1)](podman-healthcheck.1.md)| Manage healthchecks for containers                                       |
-| [podman-history(1)](podman-history.1.md)  | Show the history of an image.                                                  |
-| [podman-image(1)](podman-image.1.md)      | Manage images.                                                                 |
-| [podman-images(1)](podman-images.1.md)    | List images in local storage.                                                  |
-| [podman-import(1)](podman-import.1.md)    | Import a tarball and save it as a filesystem image.                            |
-| [podman-info(1)](podman-info.1.md)        | Displays Podman related system information.                                    |
-| [podman-init(1)](podman-init.1.md)        | Initialize a container                                                         |
-| [podman-inspect(1)](podman-inspect.1.md)  | Display a container or image's configuration.                                  |
-| [podman-kill(1)](podman-kill.1.md)        | Kill the main process in one or more containers.                               |
-| [podman-load(1)](podman-load.1.md)        | Load an image from a container image archive into container storage.           |
-| [podman-login(1)](podman-login.1.md)      | Login to a container registry.                                                 |
-| [podman-logout(1)](podman-logout.1.md)    | Logout of a container registry.                                                |
-| [podman-logs(1)](podman-logs.1.md)        | Display the logs of a container.                                               |
-| [podman-mount(1)](podman-mount.1.md)      | Mount a working container's root filesystem.                                   |
-| [podman-pause(1)](podman-pause.1.md)      | Pause one or more containers.                                                  |
-| [podman-play(1)](podman-play.1.md)        | Play pods and containers based on a structured input file.                     |
-| [podman-pod(1)](podman-pod.1.md)          | Management tool for groups of containers, called pods.                         |
-| [podman-port(1)](podman-port.1.md)        | List port mappings for a container.                                            |
-| [podman-ps(1)](podman-ps.1.md)            | Prints out information about containers.                                       |
-| [podman-pull(1)](podman-pull.1.md)        | Pull an image from a registry.                                                 |
-| [podman-push(1)](podman-push.1.md)        | Push an image from local storage to elsewhere.                                 |
-| [podman-restart(1)](podman-restart.1.md)  | Restart one or more containers.                                                |
-| [podman-rm(1)](podman-rm.1.md)            | Remove one or more containers.                                                 |
-| [podman-rmi(1)](podman-rmi.1.md)          | Removes one or more locally stored images.                                     |
-| [podman-run(1)](podman-run.1.md)          | Run a command in a new container.                                              |
-| [podman-save(1)](podman-save.1.md)        | Save an image to a container archive.                                          |
-| [podman-search(1)](podman-search.1.md)    | Search a registry for an image.                                                |
-| [podman-start(1)](podman-start.1.md)      | Start one or more containers.                                                  |
-| [podman-stats(1)](podman-stats.1.md)      | Display a live stream of one or more container's resource usage statistics.    |
-| [podman-stop(1)](podman-stop.1.md)        | Stop one or more running containers.                                           |
-| [podman-system(1)](podman-system.1.md)    | Manage podman.                                                                 |
-| [podman-tag(1)](podman-tag.1.md)          | Add an additional name to a local image.                                       |
-| [podman-top(1)](podman-top.1.md)          | Display the running processes of a container.                                  |
-| [podman-umount(1)](podman-umount.1.md)    | Unmount a working container's root filesystem.                                 |
-| [podman-unpause(1)](podman-unpause.1.md)  | Unpause one or more containers.                                                |
-| [podman-version(1)](podman-varlink.1.md)  | Runs the varlink backend interface.                                            |
-| [podman-varlink(1)](podman-version.1.md)  | Display the Podman version information.                                        |
-| [podman-volume(1)](podman-volume.1.md)    | Manage Volumes.                                                                |
-| [podman-wait(1)](podman-wait.1.md)        | Wait on one or more containers to stop and print their exit codes.             |
+| Command                                          | Description                                                                 |
+| ------------------------------------------------ | --------------------------------------------------------------------------- |
+| [podman-attach(1)](podman-attach.1.md)           | Attach to a running container.                                              |
+| [podman-build(1)](podman-build.1.md)             | Build a container image using a Dockerfile.                                 |
+| [podman-commit(1)](podman-commit.1.md)           | Create new image based on the changed container.                            |
+| [podman-container(1)](podman-container.1.md)     | Manage containers.                                                          |
+| [podman-cp(1)](podman-cp.1.md)                   | Copy files/folders between a container and the local filesystem.            |
+| [podman-create(1)](podman-create.1.md)           | Create a new container.                                                     |
+| [podman-diff(1)](podman-diff.1.md)               | Inspect changes on a container or image's filesystem.                       |
+| [podman-events(1)](podman-events.1.md)           | Monitor Podman events                                                       |
+| [podman-exec(1)](podman-exec.1.md)               | Execute a command in a running container.                                   |
+| [podman-export(1)](podman-export.1.md)           | Export a container's filesystem contents as a tar archive.                  |
+| [podman-generate(1)](podman-generate.1.md)       | Generate structured data based for a containers and pods.                   |
+| [podman-healthcheck(1)](podman-healthcheck.1.md) | Manage healthchecks for containers                                          |
+| [podman-history(1)](podman-history.1.md)         | Show the history of an image.                                               |
+| [podman-image(1)](podman-image.1.md)             | Manage images.                                                              |
+| [podman-images(1)](podman-images.1.md)           | List images in local storage.                                               |
+| [podman-import(1)](podman-import.1.md)           | Import a tarball and save it as a filesystem image.                         |
+| [podman-info(1)](podman-info.1.md)               | Displays Podman related system information.                                 |
+| [podman-init(1)](podman-init.1.md)               | Initialize a container                                                      |
+| [podman-inspect(1)](podman-inspect.1.md)         | Display a container or image's configuration.                               |
+| [podman-kill(1)](podman-kill.1.md)               | Kill the main process in one or more containers.                            |
+| [podman-load(1)](podman-load.1.md)               | Load an image from a container image archive into container storage.        |
+| [podman-login(1)](podman-login.1.md)             | Login to a container registry.                                              |
+| [podman-logout(1)](podman-logout.1.md)           | Logout of a container registry.                                             |
+| [podman-logs(1)](podman-logs.1.md)               | Display the logs of a container.                                            |
+| [podman-mount(1)](podman-mount.1.md)             | Mount a working container's root filesystem.                                |
+| [podman-pause(1)](podman-pause.1.md)             | Pause one or more containers.                                               |
+| [podman-play(1)](podman-play.1.md)               | Play pods and containers based on a structured input file.                  |
+| [podman-pod(1)](podman-pod.1.md)                 | Management tool for groups of containers, called pods.                      |
+| [podman-port(1)](podman-port.1.md)               | List port mappings for a container.                                         |
+| [podman-ps(1)](podman-ps.1.md)                   | Prints out information about containers.                                    |
+| [podman-pull(1)](podman-pull.1.md)               | Pull an image from a registry.                                              |
+| [podman-push(1)](podman-push.1.md)               | Push an image from local storage to elsewhere.                              |
+| [podman-restart(1)](podman-restart.1.md)         | Restart one or more containers.                                             |
+| [podman-rm(1)](podman-rm.1.md)                   | Remove one or more containers.                                              |
+| [podman-rmi(1)](podman-rmi.1.md)                 | Removes one or more locally stored images.                                  |
+| [podman-run(1)](podman-run.1.md)                 | Run a command in a new container.                                           |
+| [podman-save(1)](podman-save.1.md)               | Save an image to a container archive.                                       |
+| [podman-search(1)](podman-search.1.md)           | Search a registry for an image.                                             |
+| [podman-start(1)](podman-start.1.md)             | Start one or more containers.                                               |
+| [podman-stats(1)](podman-stats.1.md)             | Display a live stream of one or more container's resource usage statistics. |
+| [podman-stop(1)](podman-stop.1.md)               | Stop one or more running containers.                                        |
+| [podman-system(1)](podman-system.1.md)           | Manage podman.                                                              |
+| [podman-tag(1)](podman-tag.1.md)                 | Add an additional name to a local image.                                    |
+| [podman-top(1)](podman-top.1.md)                 | Display the running processes of a container.                               |
+| [podman-umount(1)](podman-umount.1.md)           | Unmount a working container's root filesystem.                              |
+| [podman-unpause(1)](podman-unpause.1.md)         | Unpause one or more containers.                                             |
+| [podman-unshare(1)](podman-unshare.1.md)         | Run a command inside of a modified user namespace.                          |
+| [podman-version(1)](podman-varlink.1.md)         | Runs the varlink backend interface.                                         |
+| [podman-varlink(1)](podman-version.1.md)         | Display the Podman version information.                                     |
+| [podman-volume(1)](podman-volume.1.md)           | Manage Volumes.                                                             |
+| [podman-wait(1)](podman-wait.1.md)               | Wait on one or more containers to stop and print their exit codes.          |
 
 ## FILES
 
diff --git a/test/e2e/unshare_test.go b/test/e2e/unshare_test.go
new file mode 100644
index 000000000..1e3f06a62
--- /dev/null
+++ b/test/e2e/unshare_test.go
@@ -0,0 +1,52 @@
+package integration
+
+import (
+	"os"
+
+	. "github.com/containers/libpod/test/utils"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Podman unshare", func() {
+	var (
+		tempdir    string
+		err        error
+		podmanTest *PodmanTestIntegration
+	)
+	BeforeEach(func() {
+		SkipIfRemote()
+		if _, err := os.Stat("/proc/self/uid_map"); err != nil {
+			Skip("User namespaces not supported.")
+		}
+
+		if os.Geteuid() == 0 {
+			Skip("Use unshare in rootless only")
+		}
+
+		tempdir, err = CreateTempDirInTempDir()
+		if err != nil {
+			os.Exit(1)
+		}
+		podmanTest = PodmanTestCreate(tempdir)
+		podmanTest.CgroupManager = "cgroupfs"
+		podmanTest.StorageOptions = ROOTLESS_STORAGE_OPTIONS
+		podmanTest.Setup()
+		podmanTest.RestoreAllArtifacts()
+	})
+
+	AfterEach(func() {
+		podmanTest.Cleanup()
+		f := CurrentGinkgoTestDescription()
+		processTestResult(f)
+	})
+
+	It("podman unshare", func() {
+		userNS, _ := os.Readlink("/proc/self/ns/user")
+		session := podmanTest.Podman([]string{"unshare", "readlink", "/proc/self/ns/user"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		ok, _ := session.GrepString(userNS)
+		Expect(ok).To(BeFalse())
+	})
+})