X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd-nspawn.xml;h=7d450f912c1c617c17d6bd41a32eb0d87374963a;hp=6a01ffd450aff17b573633131960762212205160;hb=accdd018ede77ef1c057775396c18c73406cbcb4;hpb=e670b166a08b7c1031a9e7d7675fa9a29c3e19c9 diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml index 6a01ffd45..7d450f912 100644 --- a/man/systemd-nspawn.xml +++ b/man/systemd-nspawn.xml @@ -49,7 +49,17 @@ - systemd-nspawn OPTIONS COMMAND ARGS + systemd-nspawn + OPTIONS + COMMAND + ARGS + + + + systemd-nspawn + -b + OPTIONS + ARGS @@ -87,14 +97,13 @@ involved with boot and systems management. In contrast to - chroot1 - systemd-nspawn may be used to boot - full Linux-based operating systems in a - container. + chroot1 systemd-nspawn + may be used to boot full Linux-based operating systems + in a container. Use a tool like yum8, - debootstrap8 + debootstrap8, or pacman8 to set up an OS directory tree suitable as file system @@ -114,21 +123,52 @@ 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 + existence 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: @@ -152,7 +192,7 @@ Directory to use as file system root for the namespace - container. If omitted the current + container. If omitted, the current directory will be used. @@ -164,7 +204,10 @@ Automatically search for an init binary and invoke it instead of a shell or a user supplied - program. + program. If this option is used, arguments + specified on the command line are used + as arguments for the init binary. + @@ -180,10 +223,35 @@ + + + + + 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. + + + + + + Make the container + part of the specified slice, instead + of the + machine.slice. + + + - Set the specified uuid + Set the specified UUID for the container. The init system will initialize /etc/machine-id @@ -191,16 +259,6 @@ - - - - - Makes the container appear in - other hierarchies than the name=systemd:/ one. - Takes a comma-separated list of controllers. - - - @@ -215,7 +273,7 @@ Mount the root file - system read only for the + system read-only for the container. @@ -224,7 +282,7 @@ List one or more additional capabilities to grant the - container. Takes a comma separated + container. Takes a comma-separated list of capability names, see capabilities7 for more information. Note that the @@ -250,7 +308,7 @@ Control whether the container's journal shall be made - visible to the host system. If enabled + visible to the host system. If enabled, allows viewing the container's journal files from the host (but not vice versa). Takes one of @@ -276,7 +334,7 @@ /var/log/journal exists, it will be bind mounted into the container. If the - subdirectory doesn't exist, no + subdirectory does not exist, no linking is performed. Effectively, booting a container once with guest or @@ -292,6 +350,26 @@ 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. + @@ -303,7 +381,7 @@ # systemd-nspawn -bD /srv/mycontainer This installs a minimal Fedora distribution into - the directory /srv/mycontainer/ and + the directory /srv/mycontainer/ and then boots an OS in a namespace container in it. @@ -318,7 +396,6 @@ distribution into the directory ~/debian-tree/ and then spawns a shell in a namespace container in it. - @@ -332,6 +409,24 @@ 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. + + Exit status @@ -344,9 +439,11 @@ systemd1, chroot1, + unshare1, yum8, debootstrap8, - pacman8 + pacman8, + systemd.slice5