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 .B cgroup namespace
  58 The process will have a virtualized view of \fI/proc\:/self\:/cgroup\fP, and new
  59 cgroup mounts will be rooted at the namespace cgroup root.
  60 .RB ( CLONE_\:NEWCGROUP
  61 flag)
  62 .TP
  63 See \fBclone\fP(2) for the exact semantics of the flags.
  64 .TP
  65 If \fIprogram\fP is not given, then ``${SHELL}'' is run (default: /bin\:/sh).
  66
  67 .SH OPTIONS
  68 .TP
  69 \fB\-t\fR, \fB\-\-target\fR \fIpid\fP
  70 Specify a target process to get contexts from.  The paths to the contexts
  71 specified by
  72 .I pid
  73 are:
  74 .RS
  75 .PD 0
  76 .IP "" 20
  77 .TP
  78 /proc/\fIpid\fR/ns/mnt
  79 the mount namespace
  80 .TP
  81 /proc/\fIpid\fR/ns/uts
  82 the UTS namespace
  83 .TP
  84 /proc/\fIpid\fR/ns/ipc
  85 the IPC namespace
  86 .TP
  87 /proc/\fIpid\fR/ns/net
  88 the network namespace
  89 .TP
  90 /proc/\fIpid\fR/ns/pid
  91 the PID namespace
  92 .TP
  93 /proc/\fIpid\fR/ns/user
  94 the user namespace
  95 .TP
  96 /proc/\fIpid\fR/ns/cgroup
  97 the cgroup namespace
  98 .TP
  99 /proc/\fIpid\fR/root
 100 the root directory
 101 .TP
 102 /proc/\fIpid\fR/cwd
 103 the working directory respectively
 104 .PD
 105 .RE
 106 .TP
 107 \fB\-m\fR, \fB\-\-mount\fR[=\fIfile\fR]
 108 Enter the mount namespace.  If no file is specified, enter the mount namespace
 109 of the target process.  If file is specified, enter the mount namespace
 110 specified by file.
 111 .TP
 112 \fB\-u\fR, \fB\-\-uts\fR[=\fIfile\fR]
 113 Enter the UTS namespace.  If no file is specified, enter the UTS namespace of
 114 the target process.  If file is specified, enter the UTS namespace specified by
 115 file.
 116 .TP
 117 \fB\-i\fR, \fB\-\-ipc\fR[=\fIfile\fR]
 118 Enter the IPC namespace.  If no file is specified, enter the IPC namespace of
 119 the target process.  If file is specified, enter the IPC namespace specified by
 120 file.
 121 .TP
 122 \fB\-n\fR, \fB\-\-net\fR[=\fIfile\fR]
 123 Enter the network namespace.  If no file is specified, enter the network
 124 namespace of the target process.  If file is specified, enter the network
 125 namespace specified by file.
 126 .TP
 127 \fB\-p\fR, \fB\-\-pid\fR[=\fIfile\fR]
 128 Enter the PID namespace.  If no file is specified, enter the PID namespace of
 129 the target process.  If file is specified, enter the PID namespace specified by
 130 file.
 131 .TP
 132 \fB\-U\fR, \fB\-\-user\fR[=\fIfile\fR]
 133 Enter the user namespace.  If no file is specified, enter the user namespace of
 134 the target process.  If file is specified, enter the user namespace specified by
 135 file.  See also the \fB\-\-setuid\fR and \fB\-\-setgid\fR options.
 136 .TP
 137 \fB\-C\fR, \fB\-\-cgroup\fR[=\fIfile\fR]
 138 Enter the cgroup namespace.  If no file is specified, enter the cgroup namespace of
 139 the target process.  If file is specified, enter the cgroup namespace specified by
 140 file.
 141 .TP
 142 \fB\-G\fR, \fB\-\-setgid\fR \fIgid\fR
 143 Set the group ID which will be used in the entered namespace and drop
 144 supplementary groups.
 145 .BR nsenter (1)
 146 always sets GID for user namespaces, the default is 0.
 147 .TP
 148 \fB\-S\fR, \fB\-\-setuid\fR \fIuid\fR
 149 Set the user ID which will be used in the entered namespace.
 150 .BR nsenter (1)
 151 always sets UID for user namespaces, the default is 0.
 152 .TP
 153 \fB\-\-preserve\-credentials\fR
 154 Don't modify UID and GID when enter user namespace. The default is to
 155 drops supplementary groups and sets GID and UID to 0.
 156 .TP
 157 \fB\-r\fR, \fB\-\-root\fR[=\fIdirectory\fR]
 158 Set the root directory.  If no directory is specified, set the root directory to
 159 the root directory of the target process.  If directory is specified, set the
 160 root directory to the specified directory.
 161 .TP
 162 \fB\-w\fR, \fB\-\-wd\fR[=\fIdirectory\fR]
 163 Set the working directory.  If no directory is specified, set the working
 164 directory to the working directory of the target process.  If directory is
 165 specified, set the working directory to the specified directory.
 166 .TP
 167 \fB\-F\fR, \fB\-\-no\-fork\fR
 168 Do not fork before exec'ing the specified program.  By default, when entering a
 169 PID namespace, \fBnsenter\fP calls \fBfork\fP before calling \fBexec\fP so that
 170 any children will also be in the newly entered PID namespace.
 171 .TP
 172 \fB\-Z\fR, \fB\-\-follow\-context\fR
 173 Set the SELinux security context used for executing a new process according to
 174 already running process specified by \fB\-\-target\fR PID. (The util-linux has
 175 to be compiled with SELinux support otherwise the option is unavailable.)
 176 .TP
 177 \fB\-V\fR, \fB\-\-version\fR
 178 Display version information and exit.
 179 .TP
 180 \fB\-h\fR, \fB\-\-help\fR
 181 Display help text and exit.
 182 .SH SEE ALSO
 183 .BR clone (2),
 184 .BR setns (2),
 185 .BR namespaces (7)
 186 .SH AUTHORS
 187 .UR biederm@xmission.com
 188 Eric Biederman
 189 .UE
 190 .br
 191 .UR kzak@redhat.com
 192 Karel Zak
 193 .UE
 194 .SH AVAILABILITY
 195 The nsenter command is part of the util-linux package and is available from
 196 .UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
 197 Linux Kernel Archive
 198 .UE .