[systemd-devel] [ANNOUNCE] systemd 233
lennart at poettering.net
Wed Mar 1 22:12:03 UTC 2017
Finally, here's systemd 233. Tons of new features, even more
CHANGES WITH 233:
* The "hybrid" control group mode has been modified to improve
compatibility with "legacy" cgroups-v1 setups. Specifically, the
"hybrid" setup of /sys/fs/cgroup is now pretty much identical to
"legacy" (including /sys/fs/cgroup/systemd as "name=systemd" named
cgroups-v1 hierarchy), the only externally visible change being that
the cgroups-v2 hierarchy is also mounted, to
/sys/fs/cgroup/unified. This should provide a large degree of
compatibility with "legacy" cgroups-v1, while taking benefit of the
better management capabilities of cgroups-v2.
* The default control group setup mode may be selected both a boot-time
via a set of kernel command line parameters (specifically:
systemd.legacy_systemd_cgroup_controller=), as well as a compile-time
default selected on the configure command line
(--with-default-hierarchy=). The upstream default is "hybrid"
(i.e. the cgroups-v1 + cgroups-v2 mixture discussed above) now, but
this will change in a future systemd version to be "unified" (pure
cgroups-v2 mode). The third option for the compile time option is
"legacy", to enter pure cgroups-v1 mode. We recommend downstream
distributions to default to "hybrid" mode for release distributions,
starting with v233. We recommend "unified" for development
distributions (specifically: distributions such as Fedora's rawhide)
as that's where things are headed in the long run. Use "legacy" for
greatest stability and compatibility only.
* Note one current limitation of "unified" and "hybrid" control group
setup modes: the kernel currently does not permit the systemd --user
instance (i.e. unprivileged code) to migrate processes between two
disconnected cgroup subtrees, even if both are managed and owned by
the user. This effectively means "systemd-run --user --scope" doesn't
work when invoked from outside of any "systemd --user" service or
scope. Specifically, it is not supported from session scopes. We are
working on fixing this in a future systemd version. (See #3388 for
further details about this.)
* DBus policy files are now installed into /usr rather than /etc. Make
sure your system has dbus >= 1.9.18 running before upgrading to this
version, or override the install path with --with-dbuspolicydir= .
* All python scripts shipped with systemd (specifically: the various
tests written in Python) now require Python 3.
* systemd unit tests can now run standalone (without the source or
build directories), and can be installed into /usr/lib/systemd/tests/
with 'make install-tests'.
* Note that from this version on, CONFIG_CRYPTO_USER_API_HASH,
CONFIG_CRYPTO_HMAC and CONFIG_CRYPTO_SHA256 need to be enabled in the
* Support for the %c, %r, %R specifiers in unit files has been
removed. Specifiers are not supposed to be dependent on configuration
in the unit file itself (so that they resolve the same regardless
where used in the unit files), but these specifiers were influenced
by the Slice= option.
* The shell invoked by debug-shell.service now defaults to /bin/sh in
all cases. If distributions want to use a different shell for this
purpose (for example Fedora's /sbin/sushell) they need to specify
this explicitly at configure time using --with-debug-shell=.
* The confirmation spawn prompt has been reworked to offer the
(c)ontinue, proceed without asking anymore
(D)ump, show the state of the unit
(f)ail, don't execute the command and pretend it failed
(i)nfo, show a short summary of the unit
(j)obs, show jobs that are in progress
(s)kip, don't execute the command and pretend it succeeded
(y)es, execute the command
The 'n' choice for the confirmation spawn prompt has been removed,
because its meaning was confusing.
The prompt may now also be redirected to an alternative console by
specifying the console as parameter to systemd.confirm_spawn=.
* Services of Type=notify require a READY=1 notification to be sent
during startup. If no such message is sent, the service now fails,
even if the main process exited with a successful exit code.
* Services that fail to start up correctly now always have their
ExecStopPost= commands executed. Previously, they'd enter "failed"
state directly, without executing these commands.
* The option MulticastDNS= of network configuration files has acquired
an actual implementation. With MulticastDNS=yes a host can resolve
names of remote hosts and reply to mDNS A and AAAA requests.
* When units are about to be started an additional check is now done to
ensure that all dependencies of type BindsTo= (when used in
combination with After=) have been started.
* systemd-analyze gained a new verb "syscall-filter" which shows which
system call groups are defined for the SystemCallFilter= unit file
setting, and which system calls they contain.
* A new system call filter group "@filesystem" has been added,
consisting of various file system related system calls. Group
"@reboot" has been added, covering reboot, kexec and shutdown related
calls. Finally, group "@swap" has been added covering swap
configuration related calls.
* A new unit file option RestrictNamespaces= has been added that may be
used to restrict access to the various process namespace types the
Linux kernel provides. Specifically, it may be used to take away the
right for a service unit to create additional file system, network,
user, and other namespaces. This sandboxing option is particularly
relevant due to the high amount of recently discovered namespacing
related vulnerabilities in the kernel.
* systemd-udev's .link files gained support for a new AutoNegotiation=
setting for configuring Ethernet auto-negotiation.
* systemd-networkd's .network files gained support for a new
ListenPort= setting in the [DHCP] section to explicitly configure the
UDP client port the DHCP client shall listen on.
* .network files gained a new Unmanaged= boolean setting for explicitly
excluding one or more interfaces from management by systemd-networkd.
* The systemd-networkd ProxyARP= option has been renamed to
IPV4ProxyARP=. Similarly, VXLAN-specific option ARPProxy= has been
renamed to ReduceARPProxy=. The old names continue to be available
* systemd-networkd gained support for configuring IPv6 Proxy NDP
addresses via the new IPv6ProxyNDPAddress= .network file setting.
* systemd-networkd's bonding device support gained support for two new
configuration options ActiveSlave= and PrimarySlave=.
* The various options in the [Match] section of .network files gained
support for negative matching.
* New systemd-specific mount options are now understood in /etc/fstab:
x-systemd.mount-timeout= may be used to configure the maximum
permitted runtime of the mount command.
x-systemd.device-bound may be set to bind a mount point to its
backing device unit, in order to automatically remove a mount point
if its backing device is unplugged. This option may also be
configured through the new SYSTEMD_MOUNT_DEVICE_BOUND udev property
on the block device, which is now automatically set for all CDROM
drives, so that mounted CDs are automatically unmounted when they are
removed from the drive.
x-systemd.after= and x-systemd.before= may be used to explicitly
order a mount after or before another unit or mount point.
* Enqueued start jobs for device units are now automatically garbage
collected if there are no jobs waiting for them anymore.
* systemctl list-jobs gained two new switches: with --after, for every
queued job the jobs it's waiting for are shown; with --before the
jobs which it's blocking are shown.
* systemd-nspawn gained support for ephemeral boots from disk images
(or in other words: --ephemeral and --image= may now be
combined). Moreover, ephemeral boots are now supported for normal
directories, even if the backing file system is not btrfs. Of course,
if the file system does not support file system snapshots or
reflinks, the initial copy operation will be relatively expensive, but
this should still be suitable for many use cases.
* Calendar time specifications in .timer units now support
specifications relative to the end of a month by using "~" instead of
"-" as separator between month and day. For example, "*-02~03" means
"the third last day in February". In addition a new syntax for
repeated events has been added using the "/" character. For example,
"9..17/2:00" means "every two hours from 9am to 5pm".
* systemd-socket-proxyd gained a new parameter --connections-max= for
configuring the maximum number of concurrent connections.
* sd-id128 gained a new API for generating unique IDs for the host in a
way that does not leak the machine ID. Specifically,
sd_id128_get_machine_app_specific() derives an ID based on the
machine ID a in well-defined, non-reversible, stable way. This is
useful whenever an identifier for the host is needed but where the
identifier shall not be useful to identify the system beyond the
scope of the application itself. (Internally this uses HMAC-SHA256 as
keyed hash function using the machine ID as input.)
* NotifyAccess= gained a new supported value "exec". When set
notifications are accepted from all processes systemd itself invoked,
including all control processes.
* .nspawn files gained support for defining overlay mounts using the
Overlay= and OverlayReadOnly= options. Previously this functionality
was only available on the systemd-nspawn command line.
* systemd-nspawn's --bind= and --overlay= options gained support for
bind/overlay mounts whose source lies within the container tree by
prefixing the source path with "+".
* systemd-nspawn's --bind= and --overlay= options gained support for
automatically allocating a temporary source directory in /var/tmp
that is removed when the container dies. Specifically, if the source
directory is specified as empty string this mechanism is selected. An
example usage is --overlay=+/var::/var, which creates an overlay
mount based on the original /var contained in the image, overlayed
with a temporary directory in the host's /var/tmp. This way changes
to /var are automatically flushed when the container shuts down.
* systemd-nspawn --image= option does now permit raw file system block
devices (in addition to images containing partition tables, as
* The disk image dissection logic in systemd-nspawn gained support for
automatically setting up LUKS encrypted as well as Verity protected
partitions. When a container is booted from an encrypted image the
passphrase is queried at start-up time. When a container with Verity
data is started, the root hash is search in a ".roothash" file
accompanying the disk image (alternatively, pass the root hash via
the new --root-hash= command line option).
* A new tool /usr/lib/systemd/systemd-dissect has been added that may
be used to dissect disk images the same way as systemd-nspawn does
it, following the Bootable Partition Specification. It may even be
used to mount disk images with complex partition setups (including
LUKS and Verity partitions) to a local host directory, in order to
inspect them. This tool is not considered public API (yet), and is
thus not installed into /usr/bin. Please do not rely on its
existence, since it might go away or be changed in later systemd
* A new generator "systemd-verity-generator" has been added, similar in
style to "systemd-cryptsetup-generator", permitting automatic setup of
Verity root partitions when systemd boots up. In order to make use of
this your partition setup should follow the Discoverable Partitions
Specification, and the GPT partition ID of the root file system
partition should be identical to the upper 128bit of the Verity root
hash. The GPT partition ID of the Verity partition protecting it
should be the lower 128bit of the Verity root hash. If the partition
image follows this model it is sufficient to specify a single
"roothash=" kernel command line argument to both configure which root
image and verity partition to use as well as the root hash for
it. Note that systemd-nspawn's Verity support follows the same
semantics, meaning that disk images with proper Verity data in place
may be booted in containers with systemd-nspawn as well as on
physical systems via the verity generator. Also note that the "mkosi"
tool available at https://github.com/systemd/mkosi has been updated
to generate Verity protected disk images following this scheme. In
fact, it has been updated to generate disk images that optionally
implement a complete UEFI SecureBoot trust chain, involving a signed
kernel and initrd image that incorporates such a root hash as well as
a Verity-enabled root partition.
* The hardware database (hwdb) udev supports has been updated to carry
* All system services are now run with a fresh kernel keyring set up
for them. The invocation ID is stored by default in it, thus
providing a safe, non-overridable way to determine the invocation
ID of each service.
* Service unit files gained new BindPaths= and BindReadOnlyPaths=
options for bind mounting arbitrary paths in a service-specific
way. When these options are used, arbitrary host or service files and
directories may be mounted to arbitrary locations in the service's
* Documentation has been added that lists all of systemd's low-level
* sd-daemon gained a new API sd_is_socket_sockaddr() for determining
whether a specific socket file descriptor matches a specified socket
* systemd-firstboot has been updated to check for the
systemd.firstboot= kernel command line option. It accepts a boolean
and when set to false the first boot questions are skipped.
* systemd-fstab-generator has been updated to check for the
systemd.volatile= kernel command line option, which either takes an
optional boolean parameter or the special value "state". If used the
system may be booted in a "volatile" boot mode. Specifically,
"systemd.volatile" is used, the root directory will be mounted as
tmpfs, and only /usr is mounted from the actual root file system. If
"systemd.volatile=state" is used, the root directory will be mounted
as usual, but /var is mounted as tmpfs. This concept provides similar
functionality as systemd-nspawn's --volatile= option, but provides it
on physical boots. Use this option for implementing stateless
systems, or testing systems with all state and/or configuration reset
to the defaults. (Note though that many distributions are not
prepared to boot up without a populated /etc or /var, though.)
* systemd-gpt-auto-generator gained support for LUKS encrypted root
partitions. Previously it only supported LUKS encrypted partitions
for all other uses, except for the root partition itself.
* Socket units gained support for listening on AF_VSOCK sockets for
communication in virtualized QEMU environments.
* The "configure" script gained a new option --with-fallback-hostname=
for specifying the fallback hostname to use if none is configured in
/etc/hostname. For example, by specifying
--with-fallback-hostname=fedora it is possible to default to a
hostname of "fedora" on pristine installations.
* systemd-cgls gained support for a new --unit= switch for listing only
the control groups of a specific unit. Similar --user-unit= has been
added for listing only the control groups of a specific user unit.
* systemd-mount gained a new --umount switch for unmounting a mount or
automount point (and all mount/automount points below it).
* systemd will now refuse full configuration reloads (via systemctl
daemon-reload and related calls) unless at least 16MiB of free space
are available in /run. This is a safety precaution in order to ensure
that generators can safely operate after the reload completed.
* A new unit file option RootImage= has been added, which has a similar
effect as RootDirectory= but mounts the service's root directory from
a disk image instead of plain directory. This logic reuses the same
image dissection and mount logic that systemd-nspawn already uses,
and hence supports any disk images systemd-nspawn supports, including
those following the Discoverable Partition Specification, as well as
Verity enabled images. This option enables systemd to run system
services directly off disk images acting as resource bundles,
possibly even including full integrity data.
* A new MountAPIVFS= unit file option has been added, taking a boolean
argument. If enabled /proc, /sys and /dev (collectively called the
"API VFS") will be mounted for the service. This is only relevant if
RootDirectory= or RootImage= is used for the service, as these mounts
are of course in place in the host mount namespace anyway.
* systemd-nspawn gained support for a new --pivot-root= switch. If
specified the root directory within the container image is pivoted to
the specified mount point, while the original root disk is moved to a
different place. This option enables booting of ostree images
directly with systemd-nspawn.
* The systemd build scripts will no longer complain if the NTP server
addresses are not changed from the defaults. Google now supports
these NTP servers officially. We still recommend downstreams to
properly register an NTP pool with the NTP pool project though.
* coredumpctl gained new new "--reverse" option for printing the list
of coredumps in reverse order.
* coredumpctl will now show additional information about truncated and
inaccessible coredumps, as well as coredumps that are still being
processed. It also gained a new --quiet switch for suppressing
additional informational message in its output.
* coredumpctl gained support for only showing coredumps newer and/or
older than specific timestamps, using the new --since= and --until=
options, reminiscent of journalctl's options by the same name.
* The systemd-coredump logic has been improved so that it may be reused
to collect backtraces in non-compiled languages, for example in
scripting languages such as Python.
* machinectl will now show the UID shift of local containers, if user
namespacing is enabled for them.
* systemd will now optionally run "environment generator" binaries at
configuration load time. They may be used to add environment
variables to the environment block passed to services invoked. One
user environment generator is shipped by default that sets up
environment variables based on files dropped into /etc/environment.d
* systemd-resolved now includes the new, recently published 2017 DNSSEC
root key (KSK).
* hostnamed has been updated to report a new chassis type of
"convertible" to cover "foldable" laptops that can both act as a
tablet and as a laptop, such as various Lenovo Yoga devices.
Contributions from: Adrián López, Alexander Galanin, Alexander
Kochetkov, Alexandros Frantzis, Andrey Ulanov, Antoine Eiche, Baruch
Siach, Bastien Nocera, Benjamin Robin, Björn, Brandon Philips, Cédric
Schieli, Charles (Chas) Williams, Christian Hesse, Daniele Medri,
Daniel Drake, Daniel Rusek, Daniel Wagner, Dan Streetman, Dave Reisner,
David Glasser, David Herrmann, David Michael, Djalal Harouni, Dmitry
Khlebnikov, Dmitry Rozhkov, Dongsu Park, Douglas Christman, Earnestly,
Emil Soleyman, Eric Cook, Evgeny Vereshchagin, Felipe Sateler, Fionn
Cleary, Florian Klink, Francesco Brozzu, Franck Bui, Gabriel Rauter,
Gianluca Boiano, Giedrius Statkevičius, Graeme Lawes, Hans de Goede,
Harald Hoyer, Ian Kelling, Ivan Shapovalov, Jakub Wilk, Janne Heß, Jan
Synacek, Jason Reeder, Jonathan Boulle, Jörg Thalheim, Jouke Witteveen,
Karl Kraus, Kees Cook, Keith Busch, Kieran Colford, kilian-k, Lennart
Poettering, Lubomir Rintel, Lucas Werkmeister, Lukas Rusak, Maarten de
Vries, Maks Naumov, Mantas Mikulėnas, Marc-Andre Lureau, Marcin Bachry,
Mark Stosberg, Martin Ejdestig, Martin Pitt, Mauricio Faria de
Oliveira, micah, Michael Biebl, Michael Shields, Michal Schmidt, Michal
Sekletar, Michel Kraus, Mike Gilbert, Mikko Ylinen, Mirza Krak,
Namhyung Kim, nikolaof, peoronoob, Peter Hutterer, Peter Körner, Philip
Withnall, Piotr Drąg, Ray Strode, Reverend Homer, Rike-Benjamin
Schuppner, Robert Kreuzer, Ronny Chevalier, Ruslan Bilovol, sammynx,
Sergey Ptashnick, Sergiusz Urbaniak, Stefan Berger, Stefan Hajnoczi,
Stefan Schweter, Stuart McLaren, Susant Sahani, Sylvain Plantefève,
Taylor Smock, Tejun Heo, Thomas Blume, Thomas H. P. Andersen, Tibor
Nagy, Tobias Stoeckmann, Tom Gundersen, Torstein Husebø, Viktar
Vaŭčkievič, Viktor Mihajlovski, Vitaly Sulimov, Waldemar Brodkorb,
Walter Garcia-Fontes, Wim de With, Yassine Imounachen, Yi EungJun,
YunQiang Su, Yu Watanabe, Zbigniew Jędrzejewski-Szmek, Александр
— Berlin, 2017-03-01
Lennart Poettering, Red Hat
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