nsenter(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | AUTHORS | SEE ALSO | AVAILABILITY | COLOPHON

NSENTER(1)                    User Commands                   NSENTER(1)

NAME         top

       nsenter - run program in different namespaces

SYNOPSIS         top

       nsenter [options] [program [arguments]]

DESCRIPTION         top

       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         top

       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(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.

AUTHORS         top

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

SEE ALSO         top

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

AVAILABILITY         top

       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/⟩.

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found
       at ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.  If you
       have a bug report for this manual page, send it to
       util-linux@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2020-12-18.  (At that time, the date of the most recent commit
       that was found in the repository was 2020-12-17.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

util-linux                      June 2013                     NSENTER(1)

Pages that refer to this page: nsenter(1)unshare(1)setns(2)ipc_namespaces(7)namespaces(7)network_namespaces(7)time_namespaces(7)uts_namespaces(7)lsns(8)