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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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NSENTER(1) User Commands NSENTER(1)
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:
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 uts_namespaces(7).
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
ipc_namespaces(7).
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. For further
details, see network_namespaces(7).
PID namespace
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).
user namespace
The process will have a distinct set of UIDs, GIDs and
capabilities. For further details, see user_namespaces(7).
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).
time namespace
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 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/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.
--user-parent
Enter the parent user namespace. Parent user namespace will
be acquired from any other enabled namespace. If combined
with --user option the parent user namespace will be fetched
from the user namespace and replace it.
-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 gid
Set the group ID which will be used in the entered namespace
and drop supplementary groups. nsenter always sets GID for
user namespaces, the default is 0. If the argument "follow"
is specified the GID of the target process is used.
-S, --setuid uid
Set the user ID which will be used in the entered namespace.
nsenter always sets UID for user namespaces, the default is
0. If the argument "follow" is specified the UID of the
target process is used.
--keep-caps
When the --user option is given, ensure that capabilities
granted in the user namespace are preserved in the child
process.
--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. The specified directory is open before
it switches to the requested namespaces.
-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. The specified directory is open
before it switches to the requested namespaces, it means the
specified directory works as "tunnel" to the current
namespace. See also --wdns.
-W, --wdns[=directory]
Set the working directory. The directory is open after switch
to the requested namespaces and after chroot(2) call. The
options --wd and --wdns are mutually exclusive.
-e, --env
Pass environment variables from the target process to the new
process being created. If this option is not provided, the
environment variables will remain the same as in the current
namespace..
-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.)
-c, --join-cgroup
Add the initiated process to the cgroup of the target
process.
-h, --help
Display help text and exit.
-V, --version
Print version and exit.
The --user-parent option requires Linux 4.9 or higher, older
kernels will raise inappropriate ioctl for device error.
Eric Biederman <[email protected]>, Karel Zak
<[email protected]>
clone(2), setns(2), namespaces(7)
For bug reports, use the issue tracker at
https://github.com/util-linux/util-linux/issues.
The nsenter command is part of the util-linux package which can
be downloaded from Linux Kernel Archive
<https://www.kernel.org/pub/linux/utils/util-linux/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
[email protected]. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to [email protected]
util-linux 2.39.594-1e0ad 2023-08-25 NSENTER(1)
Pages that refer to this page: unshare(1), setns(2), ipc_namespaces(7), mount_namespaces(7), namespaces(7), network_namespaces(7), time_namespaces(7), uts_namespaces(7), lsns(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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