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| NSENTER(1) |
User Commands |
NSENTER(1) |
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, 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 namespaces(7) and the discussion of the
CLONE_NEWUTS flag in clone(2).
- 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 namespaces(7) and the discussion
of the CLONE_NEWIPC flag in clone(2).
- 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 namespaces(7) and the
discussion of the CLONE_NEWNET flag in clone(2).
- PID namespace
- Children will have a set of PID to process mappings separate from the
nsenter process For further details, see pid_namespaces(7)
and the discussion of the CLONE_NEWPID flag in 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. For
further details, see user_namespaces(7) and the discussion of the
CLONE_NEWUSER flag in clone(2).
- 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) and the discussion of the
CLONE_NEWCGROUP flag in clone(2).
- See clone(2) for the exact semantics of the flags.
- If program is not given, then ``${SHELL}'' is run (default:
/bin/sh).
-
OPTIONS¶
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).
- -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/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.
- -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.
AVAILABILITY¶
The nsenter command is part of the util-linux package and is available from
Linux
Kernel Archive.
