Add documentations on how to setup /etc/subuid and /etc/subgid

docs/podman.1.md

@@ -171,6 +171,17 @@ Containers created by a non-root user are not visible to other users and are not
 
 It is required to have multiple uids/gids set for an user.  Be sure the user is present in the files `/etc/subuid` and `/etc/subgid`.
 
+If you have a recent version of usermod, you can execute the following
+commands to add the ranges to the files
+
+	$ sudo usermod --add-subuids 10000-75535 USERNAME
+	$ sudo usermod --add-subgids 10000-75535 USERNAME
+
+Or just add the content manually.
+
+	$ echo USERNAME:10000:65536 >> /etc/subuid
+	$ echo USERNAME:10000:65536 >> /etc/subgid
+
 Images are pulled under `XDG_DATA_HOME` when specified, otherwise in the home directory of the user under `.local/share/containers/storage`.
 
 Currently it is not possible to create a network device, so rootless containers need to run in the host network namespace.  If a rootless container creates a network namespace,

vendor.conf

@@ -11,7 +11,7 @@ github.com/containerd/continuity master
 github.com/containernetworking/cni v0.7.0-alpha1
 github.com/containernetworking/plugins 1562a1e60ed101aacc5e08ed9dbeba8e9f3d4ec1
 github.com/containers/image 134f99bed228d6297dc01d152804f6f09f185418
-github.com/containers/storage 956a1971694f18fd602b1203c0a2d192e2cc88a1
+github.com/containers/storage 17c7d1fee5603ccf6dd97edc14162fc1510e7e23
 github.com/containers/psgo 382fc951fe0a8aba62043862ce1a56f77524db87
 github.com/coreos/go-systemd v14
 github.com/cri-o/ocicni master