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  direc-
	      tory 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  capa-
	      bilities 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)