nsenter — run program in different namespaces
nsenter
[options] [ program
[arguments] ]
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:
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).
Setting hostname or domainname will not affect the rest of the system. For further details, see uts_namespaces(7).
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).
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).
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).
The process will have a distinct set of UIDs, GIDs and capabilities. For further details, see user_namespaces(7).
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).
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).
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
pidSpecify 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
gidSet 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
uidSet 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.
The nsenter command is part of the util-linux package and is available from Linux Kernel Archive
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