Linux From Scratch - Version 7.6-systemd

Chapter 6. Installing Basic System Software

6.63. Systemd-216

The systemd package contains programs for controlling the startup, running, and shutdown of the system.

Approximate build time: 2.1 SBU
Required disk space: 678 MB

6.63.1. Installation of systemd

First, create a file to allow systemd to build when using Util-Linux built in Chapter 5 and disable LTO by default: 

cat > config.cache << "EOF"
KILL=/bin/kill
HAVE_BLKID=1
BLKID_LIBS="-lblkid"
BLKID_CFLAGS="-I/tools/include/blkid"
cc_cv_CFLAGS__flto=no
EOF

LTO is disabled by default because it causes systemd and other auxiliary programs to link to libgcc_s.so, slows the build down and makes the compiled code larger.

Additionally, fix a build error when using Util-Linux built in Chapter 5: 

sed -i "s:blkid/::" $(grep -rl "blkid/blkid.h")

Apply a patch so that compat pkg-config files get installed without installing compat libs which are useless on LFS: 

patch -Np1 -i ../systemd-216-compat-1.patch

Prepare systemd for compilation: 

./configure --prefix=/usr                                           \
            --sysconfdir=/etc                                       \
            --localstatedir=/var                                    \
            --config-cache                                          \
            --with-rootprefix=                                      \
            --with-rootlibdir=/lib                                  \
            --enable-split-usr                                      \
            --disable-gudev                                         \
            --disable-firstboot                                     \
            --disable-ldconfig                                      \
            --disable-sysusers                                      \
            --without-python                                        \
            --docdir=/usr/share/doc/systemd-216                     \
            --with-dbuspolicydir=/etc/dbus-1/system.d               \
            --with-dbusinterfacedir=/usr/share/dbus-1/interfaces    \
            --with-dbussessionservicedir=/usr/share/dbus-1/services \
            --with-dbussystemservicedir=/usr/share/dbus-1/system-services

The meaning of the configure options:

--config-cache

This switch tells the build system to use the config.cache file which was created earlier.

--with-root*

These switches ensure that core programs and shared libraries are installed in the subdirectories of the root partition.

--enable-split-usr

This switch ensures that systemd will work on systems where /bin, /lib and /sbin directories are not symlinks to their /usr counterparts.

--disable-gudev --without-python

These switches disable optional features because LFS does not provide their dependencies.

--disable-firstboot

This switch prevents installation of systemd services responsible for setting up the system for the first time. They are not useful for LFS because everything is done manually.

--disable-ldconfig

This switch prevents installation of a systemd unit that runs ldconfig at boot, making the boot time longer. Remove it if the described feature is desired, even though it's not useful for source distributions such as LFS.

--disable-sysusers

This switch prevents installation of systemd services responsible for setting up the /etc/group and /etc/passwd files. Both files were created early in this chapter.

--with-dbus*

These switches ensure that D-Bus configuration files get installed in the correct locations.

Compile the package: 

make LIBRARY_PATH=/tools/lib

If you are going to run the test suite, first prevent a few test cases from running because they fail in a chroot environment: 

sed -e "s:test/udev-test.pl::g"              \
    -e "s:test-bus-cleanup\$(EXEEXT) ::g"    \
    -e "s:test-condition-util\$(EXEEXT) ::g" \
    -e "s:test-dhcp6-client\$(EXEEXT) ::g"   \
    -e "s:test-engine\$(EXEEXT) ::g"         \
    -e "s:test-journal-flush\$(EXEEXT) ::g"  \
    -e "s:test-path-util\$(EXEEXT) ::g"      \
    -e "s:test-sched-prio\$(EXEEXT) ::g"     \
    -e "s:test-strv\$(EXEEXT) ::g"           \
    -i Makefile

To test the results, issue: 

make check

Install the package: 

make LD_LIBRARY_PATH=/tools/lib install

Move NSS libraries to /lib: 

mv -v /usr/lib/libnss_{myhostname,mymachines,resolve}.so.2 /lib

Remove an unnecessary directory: 

rm -rfv /usr/lib/rpm

Create the Sysvinit compatibility symlinks, so systemd is used as the default init system: 

for tool in runlevel reboot shutdown poweroff halt telinit; do
     ln -sfv ../bin/systemctl /sbin/${tool}
done
ln -sfv ../lib/systemd/systemd /sbin/init

Remove a reference to a non-existent group: 

sed -i "s:0775 root lock:0755 root root:g" /usr/lib/tmpfiles.d/legacy.conf

Create the /etc/machine-id file needed by Journald: 

systemd-machine-id-setup

6.63.2. Contents of systemd

Installed programs: bootctl, busctl, coredumpctl, halt, hostnamectl, init, journalctl, kernel-install, localectl, loginctl, machinectl, networkctl, poweroff, reboot, runlevel, shutdown, systemctl, systemd-analyze, systemd-ask-password, systemd-cat, systemd-cgls, systemd-cgtop, systemd-delta, systemd-detect-virt, systemd-escape, systemd-inhibit, systemd-machine-id-setup, systemd-notify, systemd-nspawn, systemd-path, systemd-run, systemd-stdio-bridge, systemd-tmpfiles, systemd-tty-ask-password-agent, telinit, timedatectl, and udevadm
Installed libraries: libnss_myhostname.so.2, libnss_mymachines.so.2, libnss_resolve.so.2, libsystemd.so, libudev.so
Installed directories: /etc/binfmt.d, /etc/init.d, /etc/kernel, /etc/modules-load.d, /etc/sysctl.d, /etc/systemd, /etc/tmpfiles.d, /etc/udev, /etc/xdg/systemd, /lib/systemd, /lib/udev, /usr/include/systemd, /usr/lib/binfmt.d, /usr/lib/kernel, /usr/lib/modules-load.d, /usr/lib/sysctl.d, /usr/lib/systemd, /usr/lib/tmpfiles.d, /usr/share/doc/systemd-216, /usr/share/factory, /usr/share/systemd, /var/lib/systemd, /var/log/journal

Short Descriptions

bootctl

used to query the firmware and boot manager settings.

busctl

Used to introspect and monitor the D-Bus bus.

coredumpctl

Used to retrieve coredumps from the systemd Journal

halt

Normally invokes shutdown with the -h option, except when already in run-level 0, then it tells the kernel to halt the system; it notes in the file /var/log/wtmp that the system is being brought down.

hostnamectl

Used to query and change the system hostname and related settings.

init

The first process to be started when the kernel has initialized the hardware which takes over the boot process and starts all the proceses it is instructed to.

journalctl

Used to query the contents of the systemd Journal.

kernel-install

Used to add and remove kernel and initramfs images to and from /boot.

localectl

Used to query and change the system locale and keyboard layout settings.

loginctl

Used to introspect and control the state of the systemd Login Manager.

machinectl

Used to introspect and control the state of the systemd Virtual Machine and Container Registration Manager

poweroff

Tells the kernel to halt the system and switch off the computer (see halt).

reboot

Tells the kernel to reboot the system (see halt).

runlevel

Reports the previous and the current run-level, as noted in the last run-level record in /var/run/utmp.

shutdown

Brings the system down in a secure way, signaling all processes and notifying all logged-in users.

systemctl

Used to introspect and control the state of the systemd system and service manager.

systemd-analyze

Used to determine system boot-up performance of the current boot.

systemd-ask-password

Used to query a system password or passphrase from the user, using a question message specified on the command line.

systemd-cat

Used to connect STDOUT and STDERR of a process with the Journal.

systemd-cgls

Recursively shows the contents of the selected Linux control group hierarchy in a tree.

systemd-cgtop

Shows the top control groups of the local Linux control group hierarchy, ordered by their CPU, memory and disk I/O load.

systemd-delta

Used to identify and compare configuration files in /etc that override default counterparts in /usr.

systemd-detect-virt

Detects execution in a virtualized environment.

systemd-escape

Used to escape strings for inclusion in systemd unit names.

systemd-inhibit

Used to execute a program with a shutdown, sleep or idle inhibitor lock taken.

systemd-machine-id-setup

Used by system installer tools to initialize the machine ID stored in /etc/machine-id at install time with a randomly generated ID.

systemd-notify

Used by daemon scripts to notify the init system about status changes.

systemd-nspawn

Used to run a command or OS in a light-weight namespace container.

systemd-path

Used to query system and user paths.

systemd-run

Used to create and start a transient .service or a .scope unit and run the specified command in it.

systemd-tmpfiles

Creates, deletes and cleans up volatile and temporary files and directories, based on the configuration file format and location specified in tmpfiles.d directories.

systemd-tty-ask-password-agent

Used to list or process pending systemd password requests

telinit

Tells init which run-level to change to.

timedatectl

Used to query and change the system clock and its settings.

udevadm

Generic Udev administration tool: controls the udevd daemon, provides info from the Udev database, monitors uevents, waits for uevents to finish, tests Udev configuration, and triggers uevents for a given device.

libsystemd

systemd utility library.

libudev

A library to access Udev device information.