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.  Enterable
       namespaces are:

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

       UTS namespace
              Setting hostname or domainname will not affect the rest of the system.  (CLONE_NEWUTS flag)

       IPC namespace
              The process will have an independent namespace for System V message  queues,  semaphore  sets  and
              shared memory segments.  (CLONE_NEWIPC flag)

       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.  (CLONE_NEWNET flag)

       PID namespace
              Children will have a set of PID to process mappings separate  from  the  nsenter  process  (CLONE_
              NEWPID flag).  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.  (CLONE_NEWUSER flag)

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

       If program is not given, then ``${SHELL}'' is run (default: /bin/sh).

OPTIONS

       -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/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.

       -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

       setns(2), clone(2)

AUTHORS

       Eric Biederman
       Karel Zak

AVAILABILITY

       The nsenter command is part of the util-linux package and is available from Linux Kernel Archive.

util-linux                                          June 2013                                         NSENTER(1)