buildah-unshare

buildah-unshare(1) General Commands Manual buildah-unshare(1)

NAME

   buildah-unshare - Run a command inside of a modified user namespace.

SYNOPSIS

   buildah 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.

   buildah 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 buildah mount command.  If an unprivileged user wants to mount and work with a container, then they need to execute
   buildah unshare.  Executing buildah mount fails for unprivileged users unless the user is running inside a buildah unshare session.

OPTIONS

   --mount, -m [VARIABLE=]containerNameOrID

   Mount the containerNameOrID container while running command, and set the environment variable VARIABLE to the path of the mountpoint.   If  VARIABLE  is  not
   specified, it defaults to containerNameOrID, which may not be a valid name for an environment variable.

EXAMPLE

   buildah unshare id

   buildah unshare pwd

   buildah unshare cat /proc/self/uid_map /proc/self/gid_map

   buildah unshare rm -fr $HOME/.local/share/containers/storage /run/user/`id -u`/run

   buildah unshare --mount containerID sh -c 'cat ${containerID}/etc/os-release'

   If you want to use buildah with a mount command then you can create a script that looks something like:

          cat buildah-script.sh << _EOF
          #!/bin/sh
          ctr=$(buildah from scratch)
          mnt=$(buildah mount $ctr)
          dnf -y install --installroot=$mnt PACKAGES
          dnf -y clean all --installroot=$mnt
          buildah config --entrypoint="/bin/PACKAGE" --env "FOO=BAR" $ctr
          buildah commit $ctr imagename
          buildah unmount $ctr
          _EOF

   Then execute it with:

          buildah unshare buildah-script.sh