lxc-unshare

lxc-unshare(1) lxc-unshare(1)

NAME

   lxc-unshare - Run a task in a new set of namespaces.

SYNOPSIS

   lxc-unshare {-s, --namespaces namespaces} [-u, --user user] [-H, --hostname hostname] [-i, --ifname ifname] [-d, --daemon] [-M, --remount] {command}

DESCRIPTION

   lxc-unshare  can be used to run a task in a cloned set of namespaces. This command is mainly provided for testing purposes.  Despite its name, it always uses clone rather than unshare
   to create the new task with fresh namespaces. Apart from testing kernel regressions this should make no difference.

OPTIONS

   -s, --namespaces namespaces
          Specify the namespaces to attach to, as a pipe-separated list, e.g. NETWORK|IPC. Allowed values are MOUNT, PID, UTSNAME, IPC, USER and NETWORK. This allows one  to  change  the
          context  of  the  process  to  e.g. the network namespace of the container while retaining the other namespaces as those of the host. (The pipe symbol needs to be escaped, e.g.
          MOUNT\|PID or quoted, e.g.  "MOUNT|PID".)

   -u, --user user
          Specify a userid which the new task should become.

   -H, --hostname hostname
          Set the hostname in the new container. Only allowed if the UTSNAME namespace is set.

   -i, --ifname interfacename
          Move the named interface into the container. Only allowed if the NETWORK namespace is set. You may specify this argument multiple times to move multiple  interfaces  into  con
          tainer.

   -d, --daemon
          Daemonize (do not wait for the container to exit before exiting)

   -M, --remount
          Mount default filesystems (/proc /dev/shm and /dev/mqueue) in the container. Only allowed if MOUNT namespace is set.

EXAMPLES

   To spawn a new shell with its own UTS (hostname) namespace,

             lxc-unshare -s UTSNAME /bin/bash

   If the hostname is changed in that shell, the change will not be reflected on the host.

   To spawn a shell in a new network, pid, and mount namespace,

             lxc-unshare -s "NETWORK|PID|MOUNT" /bin/bash

   The resulting shell will have pid 1 and will see no network interfaces.  After re-mounting /proc in that shell,

             mount -t proc proc /proc

   ps output will show there are no other processes in the namespace.

   To spawn a shell in a new network, pid, mount, and hostname namespace.

             lxc-unshare -s "NETWORK|PID|MOUNT|UTSNAME" -M -H myhostname -i veth1 /bin/bash

   The resulting shell will have pid 1 and will see two network interfaces (lo and veth1). The hostname will be "myhostname" and /proc will have been remounted. ps output will show there
   are no other processes in the namespace.

SEE ALSO

   lxc(7), lxc-create(1), lxc-copy(1), lxc-destroy(1), lxc-start(1), lxc-stop(1), lxc-execute(1), lxc-console(1), lxc-monitor(1), lxc-wait(1), lxc-cgroup(1), lxc-ls(1), lxc-info(1), lxc-
   freeze(1), lxc-unfreeze(1), lxc-attach(1), lxc.conf(5)

                                                                                      2025-07-30                                                                            lxc-unshare(1)