SYSTEMD-MACHINED.SERVICE(8)ystemd-machined.serviceYSTEMD-MACHINED.SERVICE(8)
systemd-machined.service, systemd-machined - Virtual machine and
container registration manager
systemd-machined.service
/usr/lib/systemd/systemd-machined
systemd-machined is a system service that keeps track of locally
running virtual machines and containers.
systemd-machined is useful for registering and keeping track of both
OS containers (containers that share the host kernel but run a full
init system of their own and behave in most regards like a full
virtual operating system rather than just one virtualized app) and
full virtual machines (virtualized hardware running normal operating
systems and possibly different kernels).
systemd-machined should not be used for registering/keeping track of
application sandbox containers. A machine in the context of
systemd-machined is supposed to be an abstract term covering both OS
containers and full virtual machines, but not application sandboxes.
Machines registered with machined are exposed in various ways in the
system. For example:
· Tools like ps(1) will show to which machine a specific process
belongs in a column of its own, and so will
gnome-system-monitor[1] or systemd-cgls(1).
· systemd's various tools (systemctl(1), journalctl(1),
loginctl(1), hostnamectl(1), timedatectl(1), localectl(1),
machinectl(1), ...) support the -M switch to operate on local
containers instead of the host system.
· systemctl list-machines will show the system state of all local
containers, connecting to the container's init system for that.
· systemctl's --recursive switch has the effect of not only showing
the locally running services, but recursively showing the
services of all registered containers.
· The machinectl command provides access to a number of useful
operations on registered containers, such as introspecting them,
rebooting, shutting them down, and getting a login prompt on
them.
· The sd-bus(3) library exposes the sd_bus_open_system_machine(3)
call to connect to the system bus of any registered container.
· The nss-mymachines(8) module makes sure all registered containers
can be resolved via normal glibc gethostbyname(3) or
getaddrinfo(3) calls.
See systemd-nspawn(1) for some examples on how to run containers with
OS tools.
If you are interested in writing a VM or container manager that makes
use of machined, please have look at Writing Virtual Machine or
Container Managers[2]. Also see the New Control Group Interfaces[3].
The daemon provides both a C library interface (which is shared with
systemd-logind.service(8)) as well as a D-Bus interface. The library
interface may be used to introspect and watch the state of virtual
machines/containers. The bus interface provides the same but in
addition may also be used to register or terminate machines. For more
information please consult sd-login(3) and
org.freedesktop.machine1(5). and org.freedesktop.LogControl1(5)
A small companion daemon systemd-importd.service(8) is also
available, which implements importing, exporting, and downloading of
container and VM images.
For each container registered with systemd-machined.service that
employs user namespacing, users/groups are synthesized for the used
UIDs/GIDs. These are made available to the system using the
User/Group Record Lookup API via Varlink[4], and thus may be resolved
with userdbctl(1) or the usual glibc NSS calls.
systemd(1), machinectl(1), systemd-nspawn(1), nss-mymachines(8),
systemd.special(7)
1. gnome-system-monitor
https://help.gnome.org/users/gnome-system-monitor/
2. Writing Virtual Machine or Container Managers
https://www.freedesktop.org/wiki/Software/systemd/writing-vm-managers
3. New Control Group Interfaces
https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/
4. User/Group Record Lookup API via Varlink
https://systemd.io/USER_GROUP_API
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2020-08-13. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2020-08-11.) 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 man-pages@man7.org
systemd 246 SYSTEMD-MACHINED.SERVICE(8)
Pages that refer to this page: systemd-nspawn(1) , systemd.slice(5) , 30-systemd-environment-d-generator(7) , systemd.index(7)