nsenter

NSENTER(1)                       User Commands                      NSENTER(1)



NAME
       nsenter - run program with namespaces of other processes

SYNOPSIS
       nsenter [options] [program [arguments]]

DESCRIPTION
       Enters the namespaces of one or more other processes and then executes
       the specified program. If program is not given, then ``${SHELL}'' is
       run (default: /bin/sh).

       Enterable namespaces are:

       mount namespace
              Mounting and unmounting filesystems will not affect the rest of
              the system, except for filesystems which are explicitly marked
              as shared (with mount --make-shared; see /proc/self/mountinfo
              for the shared flag).  For further details, see
              mount_namespaces(7) and the discussion of the CLONE_NEWNS flag
              in clone(2).

       UTS namespace
              Setting hostname or domainname will not affect the rest of the
              system.  For further details, see namespaces(7) and the
              discussion of the CLONE_NEWUTS flag in clone(2).

       IPC namespace
              The process will have an independent namespace for POSIX message
              queues as well as System V message queues, semaphore sets and
              shared memory segments.  For further details, see namespaces(7)
              and the discussion of the CLONE_NEWIPC flag in clone(2).

       network namespace
              The process will have independent IPv4 and IPv6 stacks, IP
              routing tables, firewall rules, the /proc/net and /sys/class/net
              directory trees, sockets, etc.  For further details, see
              namespaces(7) and the discussion of the CLONE_NEWNET flag in
              clone(2).

       PID namespace
              Children will have a set of PID to process mappings separate
              from the nsenter process For further details, see
              pid_namespaces(7) and the discussion of the CLONE_NEWPID flag in
              nsenter will fork by default if changing the PID namespace, so
              that the new program and its children share the same PID
              namespace and are visible to each other.  If --no-fork is used,
              the new program will be exec'ed without forking.

       user namespace
              The process will have a distinct set of UIDs, GIDs and
              capabilities.  For further details, see user_namespaces(7) and
              the discussion of the CLONE_NEWUSER flag in clone(2).

       cgroup namespace
              The process will have a virtualized view of /proc/self/cgroup,
              and new cgroup mounts will be rooted at the namespace cgroup
              root.  For further details, see cgroup_namespaces(7) and the
              discussion of the CLONE_NEWCGROUP flag in clone(2).

       See clone(2) for the exact semantics of the flags.

OPTIONS
       Various of the options below that relate to namespaces take an optional
       file argument.  This should be one of the /proc/[pid]/ns/* files
       described in namespaces(7).

       -a, --all
              Enter all namespaces of the target process by the default
              /proc/[pid]/ns/* namespace paths. The default paths to the
              target process namespaces may be overwritten by namespace
              specific options (e.g., --all --mount=[path]).

              The user namespace will be ignored if the same as the caller's
              current user namespace. It prevents a caller that has dropped
              capabilities from regaining those capabilities via a call to
              setns().  See setns(2) for more details.

       -t, --target pid
              Specify a target process to get contexts from.  The paths to the
              contexts specified by pid are:

              /proc/pid/ns/mnt    the mount namespace
              /proc/pid/ns/uts    the UTS namespace
              /proc/pid/ns/ipc    the IPC namespace
              /proc/pid/ns/net    the network namespace
              /proc/pid/ns/pid    the PID namespace
              /proc/pid/ns/user   the user namespace
              /proc/pid/ns/cgroup the cgroup namespace
              /proc/pid/root      the root directory
              /proc/pid/cwd       the working directory respectively

       -m, --mount[=file]
              Enter the mount namespace.  If no file is specified, enter the
              mount namespace of the target process.  If file is specified,
              enter the mount namespace specified by file.

       -u, --uts[=file]
              Enter the UTS namespace.  If no file is specified, enter the UTS
              namespace of the target process.  If file is specified, enter
              the UTS namespace specified by file.

       -i, --ipc[=file]
              Enter the IPC namespace.  If no file is specified, enter the IPC
              namespace of the target process.  If file is specified, enter
              the IPC namespace specified by file.

       -n, --net[=file]
              Enter the network namespace.  If no file is specified, enter the
              network namespace of the target process.  If file is specified,
              enter the network namespace specified by file.

       -p, --pid[=file]
              Enter the PID namespace.  If no file is specified, enter the PID
              namespace of the target process.  If file is specified, enter
              the PID namespace specified by file.

       -U, --user[=file]
              Enter the user namespace.  If no file is specified, enter the
              user namespace of the target process.  If file is specified,
              enter the user namespace specified by file.  See also the
              --setuid and --setgid options.

       -C, --cgroup[=file]
              Enter the cgroup namespace.  If no file is specified, enter the
              cgroup namespace of the target process.  If file is specified,
              enter the cgroup namespace specified by file.

       -G, --setgid gid
              Set the group ID which will be used in the entered namespace and
              drop supplementary groups.  nsenter(1) always sets GID for user
              namespaces, the default is 0.

       -S, --setuid uid
              Set the user ID which will be used in the entered namespace.
              nsenter(1) always sets UID for user namespaces, the default is
              0.

       --preserve-credentials
              Don't modify UID and GID when enter user namespace. The default
              is to drops supplementary groups and sets GID and UID to 0.

       -r, --root[=directory]
              Set the root directory.  If no directory is specified, set the
              root directory to the root directory of the target process.  If
              directory is specified, set the root directory to the specified
              directory.

       -w, --wd[=directory]
              Set the working directory.  If no directory is specified, set
              the working directory to the working directory of the target
              process.  If directory is specified, set the working directory
              to the specified directory.

       -F, --no-fork
              Do not fork before exec'ing the specified program.  By default,
              when entering a PID namespace, nsenter calls fork before calling
              exec so that any children will also be in the newly entered PID
              namespace.

       -Z, --follow-context
              Set the SELinux security context used for executing a new
              process according to already running process specified by
              --target PID. (The util-linux has to be compiled with SELinux
              support otherwise the option is unavailable.)

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.

SEE ALSO
       clone(2), setns(2), namespaces(7)

AUTHORS
       Eric Biederman ⟨biederm@xmission.com⟩
       Karel Zak ⟨kzak@redhat.com⟩

AVAILABILITY
       The nsenter command is part of the util-linux package and is available
       from Linux Kernel Archive ⟨https://www.kernel.org/pub/linux/utils/util-
       linux/⟩.



util-linux                         June 2013                        NSENTER(1)