Provided by: util-linux_2.36.1-8ubuntu1_amd64 bug

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(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

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

SEE ALSO

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

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/⟩.