[systemd-devel] [ANNOUNCE] systemd 215

Lennart Poettering lennart at poettering.net
Thu Jul 3 13:59:57 PDT 2014


A lot of work to make factory reset, stateless systems and disconnected
updates working. A lot of networkd love (dhcp4 server!) and coredumpctl
is now finally really really useful.




        * A new tool systemd-sysusers has been added. This tool
          creates system users and groups in /etc/passwd and
          /etc/group, based on static declarative system user/group
          definitions in /usr/lib/sysusers.d/. This is useful to
          enable factory resets and volatile systems that boot up with
          an empty /etc directory, and thus need system users and
          groups created during early boot. systemd now also ships
          with two default sysusers.d/ files for the most basic
          users and groups systemd and the core operating system

        * A new tmpfiles snippet has been added that rebuilds the
          essential files in /etc on boot, should they be missing.

        * A directive for ensuring automatic clean-up of
          /var/cache/man/ has been removed from the default
          configuration. This line should now be shipped by the man
          implementation. The necessary change has been made to the
          man-db implementation. Note that you need to update your man
          implementation to one that ships this line, otherwise no
          automatic clean-up of /var/cache/man will take place.

        * A new condition ConditionNeedsUpdate= has been added that
          may conditionalize services to only run when /etc or /var
          are "older" than the vendor operating system resources in
          /usr. This is useful for reconstructing or updating /etc
          after an offline update of /usr or a factory reset, on the
          next reboot. Services that want to run once after such an
          update or reset should use this condition and order
          themselves before the new systemd-update-done.service, which
          will mark the two directories as fully updated. A number of
          service files have been added making use of this, to rebuild
          the udev hardware database, the journald message catalog and
          dynamic loader cache (ldconfig). The systemd-sysusers tool
          described above also makes use of this now. With this in
          place it is now possible to start up a minimal operating
          system with /etc empty cleanly. For more information on the
          concepts involved see this recent blog story:


        * A new system group "input" has been introduced, and all
          input device nodes get this group assigned. This is useful
          for system-level software to get access to input devices. It
          complements what is already done for "audio" and "video".

        * systemd-networkd learnt minimal DHCPv4 server support in
          addition to the existing DHCPv4 client support. It also
          learnt DHCPv6 client and IPv6 Router Solicitation client
          support. The DHCPv4 client gained support for static routes
          passed in from the server. Note that the [DHCPv4] section
          known in older systemd-networkd versions has been renamed to
          [DHCP] and is now also used by the DHCPv6 client. Existing
          .network files using settings of this section should be
          updated, though compatibility is maintained. Optionally, the
          client hostname may now be sent to the DHCP server.

        * networkd gained support for vxlan virtual networks as well
          as tun/tap and dummy devices.

        * networkd gained support for automatic allocation of address
          ranges for interfaces from a system-wide pool of
          addresses. This is useful for dynamically managing a large
          number of interfaces with a single network configuration
          file. In particular this is useful to easily assign
          appropriate IP addresses to the veth links of a large number
          of nspawn instances.

        * RPM macros for processing sysusers, sysctl and binfmt
          drop-in snippets at package installation time have been

        * The /etc/os-release file should now be placed in
          /usr/lib/os-release. The old location is automatically
          created as symlink. /usr/lib is the more appropriate
          location of this file, since it shall actually describe the
          vendor operating system shipped in /usr, and not the
          configuration stored in /etc.

        * .mount units gained a new boolean SloppyOptions= setting
          that maps to mount(8)'s -s option which enables permissive
          parsing of unknown mount options.

        * tmpfiles learnt a new "L+" directive which creates a symlink
          but (unlike "L") deletes a pre-existing file first, should
          it already exist and not already be the correct
          symlink. Similar, "b+", "c+" and "p+" directives have been
          added as well, which create block and character devices, as
          well as fifos in the filesystem, possibly removing any
          pre-existing files of different types.

        * For tmpfiles' "L", "L+", "C" and "C+" directives the final
          'argument' field (which so far specified the source to
          symlink/copy the files from) is now optional. If omitted the
          same file os copied from /usr/share/factory/ suffixed by the
          full destination path. This is useful for populating /etc
          with essential files, by copying them from vendor defaults
          shipped in /usr/share/factory/etc.

        * A new command "systemctl preset-all" has been added that
          applies the service preset settings to all installed unit
          files. A new switch --preset-mode= has been added that
          controls whether only enable or only disable operations
          shall be executed.

        * A new command "systemctl is-system-running" has been added
          that allows checking the overall state of the system, for
          example whether it is fully up and running.

        * When the system boots up with an empty /etc, the equivalent
          to "systemctl preset-all" is executed during early boot, to
          make sure all default services are enabled after a factory

        * systemd now contains a minimal preset file that enables the
          most basic services systemd ships by default.

        * Unit files' [Install] section gained a new DefaultInstance=
          field for defining the default instance to create if a
          template unit is enabled with no instance specified.

        * A new passive target cryptsetup-pre.target has been added
          that may be used by services that need to make they run and
          finish before the first LUKS cryptographic device is set up.

        * The /dev/loop-control and /dev/btrfs-control device nodes
          are now owned by the "disk" group by default, opening up
          access to this group.

        * systemd-coredump will now automatically generate a
          stack trace of all core dumps taking place on the system,
          based on elfutils' libdw library. This stack trace is logged
          to the journal.

        * systemd-coredump may now optionally store coredumps directly
          on disk (in /var/lib/systemd/coredump, possibly compressed),
          instead of storing them unconditionally in the journal. This
          mode is the new default. A new configuration file
          /etc/systemd/coredump.conf has been added to configure this
          and other parameters of systemd-coredump.

        * coredumpctl gained a new "info" verb to show details about a
          specific coredump. A new switch "-1" has also been added
          that makes sure to only show information about the most
          recent entry instead of all entries. Also, as the tool is
          generally useful now the "systemd-" prefix of the binary
          name has been removed. Distributions that want to maintain
          compatibility with the old name should add a symlink from
          the old name to the new name.

        * journald's SplitMode= now defaults to "uid". This makes sure
          that unprivileged users can access their own coredumps with
          coredumpctl without restrictions.

        * New kernel command line options "systemd.wants=" (for
          pulling an additional unit during boot), "systemd.mask="
          (for masking a specific unit for the boot), and
          "systemd.debug-shell" (for enabling the debug shell on tty9)
          have been added. This is implemented in the new generator

        * systemd-nspawn will now by default filter a couple of
          syscalls for containers, among them those required for
          kernel module loading, direct x86 IO port access, swap
          management, and kexec. Most importantly though
          open_by_handle_at() is now prohibited for containers,
          closing a hole similar to a recently discussed vulnerability
          in docker regarding access to files on file hierarchies the
          container should normally not have access to. Note that for
          nspawn we generally make no security claims anyway (and
          this is explicitly documented in the man page), so this is
          just a fix for one of the most obvious problems.

        * A new man page file-hierarchy(7) has been added that
          contains a minimized, modernized version of the file system
          layout systemd expects, similar in style to the FHS
          specification or hier(5). A new tool systemd-path(1) has
          been added to query many of these paths for the local
          machine and user.

        * Automatic time-based clean-up of $XDG_RUNTIME_DIR is no
          longer done. Since the directory now has a per-user size
          limit, and is cleaned on logout this appears unnecessary,
          in particular since this now brings the lifecycle of this
          directory closer in line with how IPC objects are handled.

        * systemd.pc now exports a number of additional directories,
          including $libdir (which is useful to identify the library
          path for the primary architecture of the system), and a
          couple of drop-in directories.

        * udev's predictable network interface names now use the dev_port
          sysfs attribute, introduced in linux 3.15 instead of dev_id to
          distinguish between ports of the same PCI function. dev_id should
          only be used for ports using the same HW address, hence the need
          for dev_port.

        * machined has been updated to export the OS version of a
          container (read from /etc/os-release and
          /usr/lib/os-release) on the bus. This is now shown in
          "machinectl status" for a machine.

        * A new service setting RestartForceExitStatus= has been
          added. If configured to a set of exit signals or process
          return values, the service will be restarted when the main
          daemon process exits with any of them, regardless of the
          Restart= setting.

        * systemctl's -H switch for connecting to remote systemd
          machines has been extended so that it may be used to
          directly connect to a specific container on the
          host. "systemctl -H root at foobar:waldi" will now connect as
          user "root" to host "foobar", and then proceed directly to
          the container named "waldi". Note that currently you have to
          authenticate as user "root" for this to work, as entering
          containers is a privileged operation.

        Contributions from: Andreas Henriksson, Benjamin Steinwender,
        Carl Schaefer, Christian Hesse, Colin Ian King, Cristian
        Rodríguez, Daniel Mack, Dave Reisner, David Herrmann, Eugene
        Yakubovich, Filipe Brandenburger, Frederic Crozat, Hristo
        Venev, Jan Engelhardt, Jonathan Boulle, Kay Sievers, Lennart
        Poettering, Luke Shumaker, Mantas Mikulėnas, Marc-Antoine
        Perennou, Marcel Holtmann, Michael Marineau, Michael Olbrich,
        Michał Bartoszkiewicz, Michal Sekletar, Patrik Flykt, Ronan Le
        Martret, Ronny Chevalier, Ruediger Oertel, Steven Noonan,
        Susant Sahani, Thadeu Lima de Souza Cascardo, Thomas Hindoe
        Paaboel Andersen, Tom Gundersen, Tom Hirst, Umut Tezduyar
        Lindskog, Uoti Urpala, Zbigniew Jędrzejewski-Szmek

        -- Berlin, 2014-07-03


Lennart Poettering, Red Hat

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