sys-utils/nsenter.1

   1 .TH NSENTER 1 "June 2013" "util-linux" "User Commands"
   2 .SH NAME
   3 nsenter \- run program with namespaces of other processes
   4 .SH SYNOPSIS
   5 .B nsenter
   6 [options]
   7 .RI [ program
   8 .RI [ arguments ]]
   9 .SH DESCRIPTION
  10 Enters the namespaces of one or more other processes and then executes the specified
  11 program.  Enterable namespaces are:
  12 .TP
  13 .B mount namespace
  14 Mounting and unmounting filesystems will not affect the rest of the system
  15 .RB ( CLONE_\:NEWNS
  16 flag), except for filesystems which are explicitly marked as shared (with
  17 \fBmount --make-\:shared\fP; see \fI/proc\:/self\:/mountinfo\fP for the
  18 \fBshared\fP flag).
  19 .TP
  20 .B UTS namespace
  21 Setting hostname or domainname will not affect the rest of the system.
  22 .RB ( CLONE_\:NEWUTS
  23 flag)
  24 .TP
  25 .B IPC namespace
  26 The process will have an independent namespace for System V message queues,
  27 semaphore sets and shared memory segments.
  28 .RB ( CLONE_\:NEWIPC
  29 flag)
  30 .TP
  31 .B network namespace
  32 The process will have independent IPv4 and IPv6 stacks, IP routing tables,
  33 firewall rules, the
  34 .I /proc\:/net
  35 and
  36 .I /sys\:/class\:/net
  37 directory trees, sockets, etc.
  38 .RB ( CLONE_\:NEWNET
  39 flag)
  40 .TP
  41 .B PID namespace
  42 Children will have a set of PID to process mappings separate from the
  43 .B nsenter
  44 process
  45 .RB ( CLONE_\:NEWPID
  46 flag).
  47 .B nsenter
  48 will fork by default if changing the PID namespace, so that the new program
  49 and its children share the same PID namespace and are visible to each other.
  50 If \fB\-\-no\-fork\fP is used, the new program will be exec'ed without forking.
  51 .TP
  52 .B user namespace
  53 The process will have a distinct set of UIDs, GIDs and capabilities.
  54 .RB ( CLONE_\:NEWUSER
  55 flag)
  56 .TP
  57 See \fBclone\fP(2) for the exact semantics of the flags.
  58 .TP
  59 If \fIprogram\fP is not given, then ``${SHELL}'' is run (default: /bin\:/sh).
  60
  61 .SH OPTIONS
  62 .TP
  63 \fB\-t\fR, \fB\-\-target\fR \fIpid\fP
  64 Specify a target process to get contexts from.  The paths to the contexts
  65 specified by
  66 .I pid
  67 are:
  68 .RS
  69 .PD 0
  70 .IP "" 20
  71 .TP
  72 /proc/\fIpid\fR/ns/mnt
  73 the mount namespace
  74 .TP
  75 /proc/\fIpid\fR/ns/uts
  76 the UTS namespace
  77 .TP
  78 /proc/\fIpid\fR/ns/ipc
  79 the IPC namespace
  80 .TP
  81 /proc/\fIpid\fR/ns/net
  82 the network namespace
  83 .TP
  84 /proc/\fIpid\fR/ns/pid
  85 the PID namespace
  86 .TP
  87 /proc/\fIpid\fR/ns/user
  88 the user namespace
  89 .TP
  90 /proc/\fIpid\fR/root
  91 the root directory
  92 .TP
  93 /proc/\fIpid\fR/cwd
  94 the working directory respectively
  95 .PD
  96 .RE
  97 .TP
  98 \fB\-m\fR, \fB\-\-mount\fR[=\fIfile\fR]
  99 Enter the mount namespace.  If no file is specified, enter the mount namespace
 100 of the target process.  If file is specified, enter the mount namespace
 101 specified by file.
 102 .TP
 103 \fB\-u\fR, \fB\-\-uts\fR[=\fIfile\fR]
 104 Enter the UTS namespace.  If no file is specified, enter the UTS namespace of
 105 the target process.  If file is specified, enter the UTS namespace specified by
 106 file.
 107 .TP
 108 \fB\-i\fR, \fB\-\-ipc\fR[=\fIfile\fR]
 109 Enter the IPC namespace.  If no file is specified, enter the IPC namespace of
 110 the target process.  If file is specified, enter the IPC namespace specified by
 111 file.
 112 .TP
 113 \fB\-n\fR, \fB\-\-net\fR[=\fIfile\fR]
 114 Enter the network namespace.  If no file is specified, enter the network
 115 namespace of the target process.  If file is specified, enter the network
 116 namespace specified by file.
 117 .TP
 118 \fB\-p\fR, \fB\-\-pid\fR[=\fIfile\fR]
 119 Enter the PID namespace.  If no file is specified, enter the PID namespace of
 120 the target process.  If file is specified, enter the PID namespace specified by
 121 file.
 122 .TP
 123 \fB\-U\fR, \fB\-\-user\fR[=\fIfile\fR]
 124 Enter the user namespace.  If no file is specified, enter the user namespace of
 125 the target process.  If file is specified, enter the user namespace specified by
 126 file.  See also the \fB\-\-setuid\fR and \fB\-\-setgid\fR options.
 127 .TP
 128 \fB\-G\fR, \fB\-\-setgid\fR \fIgid\fR
 129 Set the group ID which will be used in the entered namespace and drop
 130 supplementary groups.
 131 .BR nsenter (1)
 132 always sets GID for user namespaces, the default is 0.
 133 .TP
 134 \fB\-S\fR, \fB\-\-setuid\fR \fIuid\fR
 135 Set the user ID which will be used in the entered namespace.
 136 .BR nsenter (1)
 137 always sets UID for user namespaces, the default is 0.
 138 .TP
 139 \fB\-\-preserve\-credentials\fR
 140 Don't modify UID and GID when enter user namespace. The default is to
 141 drops supplementary groups and sets GID and UID to 0.
 142 .TP
 143 \fB\-r\fR, \fB\-\-root\fR[=\fIdirectory\fR]
 144 Set the root directory.  If no directory is specified, set the root directory to
 145 the root directory of the target process.  If directory is specified, set the
 146 root directory to the specified directory.
 147 .TP
 148 \fB\-w\fR, \fB\-\-wd\fR[=\fIdirectory\fR]
 149 Set the working directory.  If no directory is specified, set the working
 150 directory to the working directory of the target process.  If directory is
 151 specified, set the working directory to the specified directory.
 152 .TP
 153 \fB\-F\fR, \fB\-\-no\-fork\fR
 154 Do not fork before exec'ing the specified program.  By default, when entering a
 155 PID namespace, \fBnsenter\fP calls \fBfork\fP before calling \fBexec\fP so that
 156 any children will also be in the newly entered PID namespace.
 157 .TP
 158 \fB\-V\fR, \fB\-\-version\fR
 159 Display version information and exit.
 160 .TP
 161 \fB\-h\fR, \fB\-\-help\fR
 162 Display help text and exit.
 163 .SH SEE ALSO
 164 .BR setns (2),
 165 .BR clone (2)
 166 .SH AUTHOR
 167 .MT ebiederm@xmission.com
 168 Eric Biederman
 169 .ME
 170 .SH AVAILABILITY
 171 The nsenter command is part of the util-linux package and is available from
 172 .UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
 173 Linux Kernel Archive
 174 .UE .