nsenter

NSENTER(1)                       User Commands                      NSENTER(1)

NAME
       nsenter - run program in different namespaces

SYNOPSIS
       nsenter [options] [program [arguments]]

DESCRIPTION
       The nsenter command executes program in the namespace(s) that are
       specified in the command-line options (described below). 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 uts_namespaces(7).

       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 ipc_namespaces(7).

       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
           network_namespaces(7).

       PID namespace
           Children will have a set of PID to process mappings separate from
           the nsenter process. 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. For further
           details, see pid_namespaces(7).

       user namespace
           The process will have a distinct set of UIDs, GIDs and
           capabilities. For further details, see user_namespaces(7).

       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).

       time namespace
           The process can have a distinct view of CLOCK_MONOTONIC and/or
           CLOCK_BOOTTIME which can be changed using
           /proc/self/timens_offsets. For further details, see
           time_namespaces(7).

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), or the pathname of a bind mount that was
       created on one of those files.

       -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/ns/time
               the time 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.

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

       -G, --setgid gid
           Set the group ID which will be used in the entered namespace and
           drop supplementary groups. nsenter 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 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.

AUTHORS
       Eric Biederman <biederm@xmission.com>, Karel Zak <kzak@redhat.com>

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

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY
       The nsenter command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.37.2                 2021-06-02                        NSENTER(1)