X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd-nspawn.xml;h=1bc61e83a76b048e3f27582a30fc30e4aed65fbc;hp=667e75c2cd70dd131c0572ce0bef4bdd517276ca;hb=77b6e19458f37cfde127ec6aa9494c0ac45ad890;hpb=2b583ce6576d4a074ce6f1570b3e60b65c64ae7d diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml index 667e75c2c..1bc61e83a 100644 --- a/man/systemd-nspawn.xml +++ b/man/systemd-nspawn.xml @@ -8,16 +8,16 @@ Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . --> @@ -49,7 +49,17 @@ - systemd-nspawn OPTIONS COMMAND ARGS + systemd-nspawn + OPTIONS + COMMAND + ARGS + + + + systemd-nspawn + -b + OPTIONS + ARGS @@ -61,7 +71,7 @@ container. In many ways it is similar to chroot1, but more powerful since it fully virtualizes the file - system hierachy, as well as the process tree, the + system hierarchy, as well as the process tree, the various IPC subsystems and the host and domain name. @@ -69,11 +79,12 @@ to various kernel interfaces in the container to read-only, such as /sys, /proc/sys or - /selinux. Network interfaces and - the system clock may not be changed from within the - container. Device nodes may not be created. The host - system cannot be rebooted and kernel modules may not - be loaded from within the container. + /sys/fs/selinux. Network + interfaces and the system clock may not be changed + from within the container. Device nodes may not be + created. The host system cannot be rebooted and kernel + modules may not be loaded from within the + container. Note that even though these security precautions are taken systemd-nspawn is not @@ -92,9 +103,13 @@ container. Use a tool like - debootstrap8 or mock1 + yum8, + debootstrap8 + or + pacman8 to set up an OS directory tree suitable as file system - hierarchy for systemd-nspawn containers. + hierarchy for systemd-nspawn + containers. Note that systemd-nspawn will mount file systems private to the container to @@ -106,22 +121,59 @@ Note that running two systemd-nspawn containers from the same directory tree will not make processes in them - see each other. The PID namespace seperation of the + see each other. The PID namespace separation of the two containers is complete and the containers will share very few runtime objects except for the - underlying file system. + underlying file system. It is however possible to + enter an existing container, see + Example 4 below. + + + systemd-nspawn implements the + Container + Interface specification. + + As a safety check + systemd-nspawn will verify the + existance of /etc/os-release in + the container tree before starting the container (see + os-release5). It + might be necessary to add this file to the container + tree manually if the OS of the container is too old to + contain this file out-of-the-box. + + + + Incompatibility with Auditing + + Note that the kernel auditing subsystem is + currently broken when used together with + containers. We hence recommend turning it off entirely + by booting with audit=0 on the + kernel command line, or by turning it off at kernel + build time. If auditing is enabled in the kernel + operating systems booted in an nspawn container might + refuse log-in attempts. Options - If no arguments are passed the container is set - up and a shell started in it, otherwise the passed - command and arguments are executed in it. The - following options are understood: + If option is specified, the + arguments are used as arguments for the init + binary. Otherwise, COMMAND + specifies the program to launch in the container, and + the remaining arguments are used as arguments for this + program. If is not used and no + arguments are specifed, a shell is launched in the + container. + + The following options are understood: + Prints a short help @@ -129,8 +181,15 @@ + + + Prints a version string + and exits. + + + + - Directory to use as file system root for the namespace @@ -139,6 +198,179 @@ used. + + + + + Automatically search + for an init binary and invoke it + instead of a shell or a user supplied + program. If this option is used, arguments + specified on the command line are used + as arguments for the init binary. + + + + + + + + Run the command + under specified user, create home + directory and cd into it. As rest + of systemd-nspawn, this is not + the security feature and limits + against accidental changes only. + + + + + + + + Sets the machine name + for this container. This name may be + used to identify this container on the + host, and is used to initialize the + container's hostname (which the + container can choose to override, + however). If not specified the last + component of the root directory of the + container is used. + + + + + + Set the specified uuid + for the container. The init system + will initialize + /etc/machine-id + from this if this file is not set yet. + + + + + + + + Makes the container appear in + other hierarchies than the name=systemd:/ one. + Takes a comma-separated list of controllers. + + + + + + + Turn off networking in + the container. This makes all network + interfaces unavailable in the + container, with the exception of the + loopback device. + + + + + + Mount the root file + system read only for the + container. + + + + + + List one or more + additional capabilities to grant the + container. Takes a comma separated + list of capability names, see + capabilities7 + for more information. Note that the + following capabilities will be granted + in any way: CAP_CHOWN, + CAP_DAC_OVERRIDE, CAP_DAC_READ_SEARCH, + CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER, + CAP_KILL, CAP_LEASE, + CAP_LINUX_IMMUTABLE, + CAP_NET_BIND_SERVICE, + CAP_NET_BROADCAST, CAP_NET_RAW, + CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP, + CAP_SETUID, CAP_SYS_ADMIN, + CAP_SYS_CHROOT, CAP_SYS_NICE, + CAP_SYS_PTRACE, CAP_SYS_TTY_CONFIG, + CAP_SYS_RESOURCE, CAP_SYS_BOOT, + CAP_AUDIT_WRITE, + CAP_AUDIT_CONTROL. + + + + + + Control whether the + container's journal shall be made + visible to the host system. If enabled + allows viewing the container's journal + files from the host (but not vice + versa). Takes one of + no, + host, + guest, + auto. If + no, the journal is + not linked. If host, + the journal files are stored on the + host file system (beneath + /var/log/journal/machine-id) + and the subdirectory is bind-mounted + into the container at the same + location. If guest, + the journal files are stored on the + guest file system (beneath + /var/log/journal/machine-id) + and the subdirectory is symlinked into the host + at the same location. If + auto (the default), + and the right subdirectory of + /var/log/journal + exists, it will be bind mounted + into the container. If the + subdirectory doesn't exist, no + linking is performed. Effectively, + booting a container once with + guest or + host will link the + journal persistently if further on + the default of auto + is used. + + + + + + Equivalent to + . + + + + + + + Bind mount a file or + directory from the host into the + container. Either takes a path + argument -- in which case the + specified path will be mounted from + the host to the same path in the + container --, or a colon-separated + pair of paths -- in which case the + first specified path is the source in + the host, and the second path is the + destination in the container. The + option + creates read-only bind + mount. + @@ -146,28 +378,54 @@ Example 1 - # debootstrap --arch=amd64 unstable debian-tree/ -# systemd-nspawn -D debian-tree/ + # yum -y --releasever=19 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal +# systemd-nspawn -bD /srv/mycontainer + + This installs a minimal Fedora distribution into + the directory /srv/mycontainer/ and + then boots an OS in a namespace container in + it. + + + + Example 2 + + # debootstrap --arch=amd64 unstable ~/debian-tree/ +# systemd-nspawn -D ~/debian-tree/ This installs a minimal Debian unstable distribution into the directory - debian-tree/ and then spawns a + ~/debian-tree/ and then spawns a shell in a namespace container in it. - - Example 2 + Example 3 - # mock --init -# systemd-nspawn -D /var/lib/mock/fedora-rawhide-x86_64/root/ /bin/systemd systemd.log_level=debug + # pacstrap -c -d ~/arch-tree/ base +# systemd-nspawn -bD ~/arch-tree/ - This installs a minimal Fedora distribution into - a subdirectory of /var/lib/mock/ - and then boots an OS in a namespace container in it, - with systemd as init system, configured for debug - logging. + This installs a mimimal Arch Linux distribution into + the directory ~/arch-tree/ and then + boots an OS in a namespace container in it. + + + + Example 4 + + To enter the container, PID of one of the + processes sharing the new namespaces must be used. + systemd-nspawn prints the PID + (as viewed from the outside) of the launched process, + and it can be used to enter the container. + + # nsenter -m -u -i -n -p -t $PID + nsenter1 + is part of + util-linux. + Kernel support for entering namespaces was added in + Linux 3.8. @@ -182,8 +440,10 @@ systemd1, chroot1, - debootstrap8 - mock1 + unshare1, + yum8, + debootstrap8, + pacman8