1NSENTER(1) User Commands NSENTER(1)
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6 nsenter - run program in different namespaces
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9 nsenter [options] [program [arguments]]
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12 The nsenter command executes program in the namespace(s) that are
13 specified in the command-line options (described below). If program is
14 not given, then "${SHELL}" is run (default: /bin/sh).
15 Enterable namespaces are:
17 mount namespace
19 Mounting and unmounting filesystems will not affect the rest of the
20 system, except for filesystems which are explicitly marked as
21 shared (with mount --make-shared; see /proc/self/mountinfo for the
22 shared flag). For further details, see mount_namespaces(7) and the
23 discussion of the CLONE_NEWNS flag in clone(2).
24 UTS namespace
26 Setting hostname or domainname will not affect the rest of the
27 system. For further details, see uts_namespaces(7).
28 IPC namespace
30 The process will have an independent namespace for POSIX message
31 queues as well as System V message queues, semaphore sets and
32 shared memory segments. For further details, see ipc_namespaces(7).
33 network namespace
35 The process will have independent IPv4 and IPv6 stacks, IP routing
36 tables, firewall rules, the /proc/net and /sys/class/net directory
37 trees, sockets, etc. For further details, see
38 network_namespaces(7).
39 PID namespace
41 Children will have a set of PID to process mappings separate from
42 the nsenter process. nsenter will fork by default if changing the
43 PID namespace, so that the new program and its children share the
44 same PID namespace and are visible to each other. If --no-fork is
45 used, the new program will be exec’ed without forking. For further
46 details, see pid_namespaces(7).
47 user namespace
49 The process will have a distinct set of UIDs, GIDs and
50 capabilities. For further details, see user_namespaces(7).
51 cgroup namespace
53 The process will have a virtualized view of /proc/self/cgroup, and
54 new cgroup mounts will be rooted at the namespace cgroup root. For
55 further details, see cgroup_namespaces(7).
56 time namespace
58 The process can have a distinct view of CLOCK_MONOTONIC and/or
59 CLOCK_BOOTTIME which can be changed using
60 /proc/self/timens_offsets. For further details, see
61 time_namespaces(7).
62
64 Various of the options below that relate to namespaces take an optional
65 file argument. This should be one of the /proc/[pid]/ns/* files
66 described in namespaces(7), or the pathname of a bind mount that was
67 created on one of those files.
68 -a, --all
70 Enter all namespaces of the target process by the default
71 /proc/[pid]/ns/* namespace paths. The default paths to the target
72 process namespaces may be overwritten by namespace specific options
73 (e.g., --all --mount=[path]).
74 The user namespace will be ignored if the same as the caller’s
76 current user namespace. It prevents a caller that has dropped
77 capabilities from regaining those capabilities via a call to
78 setns(). See setns(2) for more details.
79 -t, --target PID
81 Specify a target process to get contexts from. The paths to the
82 contexts specified by pid are:
83 /proc/pid/ns/mnt
85 the mount namespace
86 /proc/pid/ns/uts
88 the UTS namespace
89 /proc/pid/ns/ipc
91 the IPC namespace
92 /proc/pid/ns/net
94 the network namespace
95 /proc/pid/ns/pid
97 the PID namespace
98 /proc/pid/ns/user
100 the user namespace
101 /proc/pid/ns/cgroup
103 the cgroup namespace
104 /proc/pid/ns/time
106 the time namespace
107 /proc/pid/root
109 the root directory
110 /proc/pid/cwd
112 the working directory respectively
113 -m, --mount[=file]
115 Enter the mount namespace. If no file is specified, enter the mount
116 namespace of the target process. If file is specified, enter the
117 mount namespace specified by file.
118 -u, --uts[=file]
120 Enter the UTS namespace. If no file is specified, enter the UTS
121 namespace of the target process. If file is specified, enter the
122 UTS namespace specified by file.
123 -i, --ipc[=file]
125 Enter the IPC namespace. If no file is specified, enter the IPC
126 namespace of the target process. If file is specified, enter the
127 IPC namespace specified by file.
128 -n, --net[=file]
130 Enter the network namespace. If no file is specified, enter the
131 network namespace of the target process. If file is specified,
132 enter the network namespace specified by file.
133 -p, --pid[=file]
135 Enter the PID namespace. If no file is specified, enter the PID
136 namespace of the target process. If file is specified, enter the
137 PID namespace specified by file.
138 -U, --user[=file]
140 Enter the user namespace. If no file is specified, enter the user
141 namespace of the target process. If file is specified, enter the
142 user namespace specified by file. See also the --setuid and
143 --setgid options.
144 -C, --cgroup[=file]
146 Enter the cgroup namespace. If no file is specified, enter the
147 cgroup namespace of the target process. If file is specified, enter
148 the cgroup namespace specified by file.
149 -T, --time[=file]
151 Enter the time namespace. If no file is specified, enter the time
152 namespace of the target process. If file is specified, enter the
153 time namespace specified by file.
154 -G, --setgid gid
156 Set the group ID which will be used in the entered namespace and
157 drop supplementary groups. nsenter always sets GID for user
158 namespaces, the default is 0.
159 -S, --setuid uid
161 Set the user ID which will be used in the entered namespace.
162 nsenter always sets UID for user namespaces, the default is 0.
163 --preserve-credentials
165 Don’t modify UID and GID when enter user namespace. The default is
166 to drops supplementary groups and sets GID and UID to 0.
167 -r, --root[=directory]
169 Set the root directory. If no directory is specified, set the root
170 directory to the root directory of the target process. If directory
171 is specified, set the root directory to the specified directory.
172 -w, --wd[=directory]
174 Set the working directory. If no directory is specified, set the
175 working directory to the working directory of the target process.
176 If directory is specified, set the working directory to the
177 specified directory.
178 -F, --no-fork
180 Do not fork before exec’ing the specified program. By default, when
181 entering a PID namespace, nsenter calls fork before calling exec so
182 that any children will also be in the newly entered PID namespace.
183 -Z, --follow-context
185 Set the SELinux security context used for executing a new process
186 according to already running process specified by --target PID.
187 (The util-linux has to be compiled with SELinux support otherwise
188 the option is unavailable.)
189 -V, --version
191 Display version information and exit.
192 -h, --help
194 Display help text and exit.
195
197 Eric Biederman <biederm@xmission.com>, Karel Zak <kzak@redhat.com>
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200 clone(2), setns(2), namespaces(7)
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203 For bug reports, use the issue tracker at
204 https://github.com/karelzak/util-linux/issues.
205
207 The nsenter command is part of the util-linux package which can be
208 downloaded from Linux Kernel Archive
209 <https://www.kernel.org/pub/linux/utils/util-linux/>.
210util-linux 2.37.2 2021-06-02 NSENTER(1)