-systemd System and Service Manager
-
-DETAILS:
- http://0pointer.de/blog/projects/systemd.html
-
-WEB SITE:
- http://www.freedesktop.org/wiki/Software/systemd
-
-GIT:
- git://anongit.freedesktop.org/systemd/systemd
- ssh://git.freedesktop.org/git/systemd/systemd
-
-GITWEB:
- http://cgit.freedesktop.org/systemd/systemd
-
-MAILING LIST:
- http://lists.freedesktop.org/mailman/listinfo/systemd-devel
- http://lists.freedesktop.org/mailman/listinfo/systemd-commits
-
-IRC:
- #systemd on irc.freenode.org
-
-BUG REPORTS:
- https://bugs.freedesktop.org/enter_bug.cgi?product=systemd
-
-AUTHOR:
- Lennart Poettering
- Kay Sievers
- ...and many others
-
-LICENSE:
- LGPLv2.1+ for all code
- - except sd-daemon.[ch] and sd-readahead.[ch] which are MIT
- - except src/shared/MurmurHash2.c which is Public Domain
- - except src/shared/siphash24.c which is CC0 Public Domain
- - except src/journal/lookup3.c which is Public Domain
- - except src/udev/* which is (currently still) GPLv2, GPLv2+
-
-REQUIREMENTS:
- Linux kernel >= 3.0
- CONFIG_DEVTMPFS
- CONFIG_CGROUPS (it's OK to disable all controllers)
- CONFIG_INOTIFY_USER
- CONFIG_SIGNALFD
- CONFIG_TIMERFD
- CONFIG_EPOLL
- CONFIG_NET
- CONFIG_SYSFS
- CONFIG_PROC_FS
- CONFIG_FHANDLE (libudev, mount and bind mount handling)
-
- Linux kernel >= 3.8 for Smack support
-
- Udev will fail to work with the legacy layout:
- CONFIG_SYSFS_DEPRECATED=n
-
- Legacy hotplug slows down the system and confuses udev:
- CONFIG_UEVENT_HELPER_PATH=""
-
- Userspace firmware loading is deprecated, will go away, and
- sometimes causes problems:
- CONFIG_FW_LOADER_USER_HELPER=n
-
- Some udev rules and virtualization detection relies on it:
- CONFIG_DMIID
-
- Support for some SCSI devices serial number retrieval, to
- create additional symlinks in /dev/disk/ and /dev/tape:
- CONFIG_BLK_DEV_BSG
-
- Optional but strongly recommended:
- CONFIG_IPV6
- CONFIG_AUTOFS4_FS
- CONFIG_TMPFS_POSIX_ACL
- CONFIG_TMPFS_XATTR
- CONFIG_SECCOMP
-
- For systemd-bootchart, several proc debug interfaces are required:
- CONFIG_SCHEDSTATS
- CONFIG_SCHED_DEBUG
-
- For UEFI systems:
- CONFIG_EFI_VARS
- CONFIG_EFI_PARTITION
-
- Note that kernel auditing is broken when used with systemd's
- container code. When using systemd in conjunction with
- containers, please make sure to either turn off auditing at
- runtime using the kernel command line option "audit=0", or
- turn it off at kernel compile time using:
- CONFIG_AUDIT=n
-
- glibc >= 2.14
- libcap
- libseccomp >= 1.0.0 (optional)
- libblkid >= 2.20 (from util-linux) (optional)
- libkmod >= 15 (optional)
- PAM >= 1.1.2 (optional)
- libcryptsetup (optional)
- libaudit (optional)
- libacl (optional)
- libattr (optional)
- libselinux (optional)
- liblzma (optional)
- tcpwrappers (optional)
- libgcrypt (optional)
- libqrencode (optional)
- libmicrohttpd (optional)
- libpython (optional)
- make, gcc, and similar tools
-
- To sucessfully use --compat-libs, gcc >= 4.8 seems necessary.
-
- During runtime, you need the following additional
- dependencies:
-
- util-linux >= v2.19 (requires fsck -l, agetty -s),
- v2.21 required for tests in test/
- dbus >= 1.4.0 (strictly speaking optional, but recommended)
- sulogin (from util-linux >= 2.22 or sysvinit-tools, optional but recommended,
- required for tests in test/)
- dracut (optional)
- PolicyKit (optional)
-
- When building from git, you need the following additional
- dependencies:
-
- docbook-xsl
- xsltproc
- automake
- autoconf
- libtool
- intltool
- gperf
- gtkdocize (optional)
- python (optional)
- python-lxml (optional, but required to build the indices)
- sphinx (optional)
-
- When systemd-hostnamed is used, it is strongly recommended to
- install nss-myhostname to ensure that, in a world of
- dynamically changing hostnames, the hostname stays resolvable
- under all circumstances. In fact, systemd-hostnamed will warn
- if nss-myhostname is not installed.
-
- To build HTML documentation for python-systemd using sphinx,
- please first install systemd (using 'make install'), and then
- invoke sphinx-build with 'make sphinx-<target>', with <target>
- being 'html' or 'latexpdf'. If using DESTDIR for installation,
- pass the same DESTDIR to 'make sphinx-html' invocation.
-
-USERS AND GROUPS:
- Default udev rules use the following standard system group
- names, which need to be resolvable by getgrnam() at any time,
- even in the very early boot stages, where no other databases
- and network are available:
-
- tty, dialout, kmem, video, audio, lp, floppy, cdrom, tape, disk
-
- During runtime, the journal daemon requires the
- "systemd-journal" system group to exist. New journal files will
- be readable by this group (but not writable), which may be used
- to grant specific users read access.
-
- It is also recommended to grant read access to all journal
- files to the system groups "wheel" and "adm" with a command
- like the following in the post installation script of the
- package:
-
- # setfacl -nm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal/
-
- The journal gateway daemon requires the
- "systemd-journal-gateway" system user and group to
- exist. During execution this network facing service will drop
- privileges and assume this uid/gid for security reasons.
-
-WARNINGS:
- systemd will warn you during boot if /etc/mtab is not a
- symlink to /proc/mounts. Please ensure that /etc/mtab is a
- proper symlink.
-
- systemd will warn you during boot if /usr is on a different
- file system than /. While in systemd itself very little will
- break if /usr is on a separate partition, many of its
- dependencies very likely will break sooner or later in one
- form or another. For example, udev rules tend to refer to
- binaries in /usr, binaries that link to libraries in /usr or
- binaries that refer to data files in /usr. Since these
- breakages are not always directly visible, systemd will warn
- about this, since this kind of file system setup is not really
- supported anymore by the basic set of Linux OS components.
-
- For more information on this issue consult
- http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
-
- To run systemd under valgrind, compile with VALGRIND defined
- (e.g. ./configure CPPFLAGS='... -DVALGRIND=1'). Otherwise,
- false positives will be triggered by code which violates
- some rules but is actually safe.
+Elogind User, Seat and Session Manager
+
+Introduction
+------------
+
+Elogind is the systemd project's "logind", extracted out to be a
+standalone daemon. It integrates with PAM to know the set of users
+that are logged in to a system and whether they are logged in
+graphically, on the console, or remotely. Elogind exposes this
+information via the standard org.freedesktop.login1 D-Bus interface,
+as well as through the file system using systemd's standard
+/run/systemd layout. Elogind also provides "libelogind", which is a
+subset of the facilities offered by "libsystemd". There is a
+"libelogind.pc" pkg-config file as well.
+
+All of the credit for elogind should go to the systemd developers.
+For more on systemd, see
+http://www.freedesktop.org/wiki/Software/systemd. All of the blame
+should go to Andy Wingo, who extracted elogind from systemd.
+
+Contributing
+------------
+
+Elogind was branched from systemd version 219, and preserves the git
+history of the systemd project. The version of elogind is the
+upstream systemd version, followed by the patchlevel of elogind. For
+example version 219.12 is the twelfth elogind release, which aims to
+provide a subset of the interfaces of systemd 219.
+
+To contribute to elogind, fork the current source code from github:
+
+ https://github.com/elogind/elogind
+
+Send a pull request for the changes you like.
+
+To chat about elogind:
+
+ #guix on irc.freenode.org
+
+Finally, bug reports:
+
+ https://github.com/elogind/elogind/issues
+
+Why bother?
+-----------
+
+Elogind has been developed for use in GuixSD, the OS distribution of
+GNU Guix. See http://gnu.org/s/guix for more on Guix. GuixSD uses a
+specific init manager (DMD), for reasons that are not relevant here,
+but still aims to eventually be a full-featured distribution that can
+run GNOME and other desktop environments. However, to run GNOME these
+days means that you need to have support for the login1 D-Bus
+interface, which is currently only provided by systemd. That is the
+origin of this project: to take the excellent logind functionality
+from systemd and provide it as a standalone package.
+
+We like systemd. We realize that there are people out there that hate
+it. You're welcome to use elogind for whatever purpose you like --
+as-is, or as a jumping-off point for other things -- but please don't
+use it as part of some anti-systemd vendetta. Systemd hackers are
+smart folks that are trying to solve interesting problems on the free
+desktop, and their large adoption is largely because they solve
+problems that users and developers of user-focused applications care
+about. We are appreciative of their logind effort and think that
+everyone deserves to run it if they like, even if they use a different
+PID 1.
+
+Differences relative to systemd
+-------------------------------
+
+The pkg-config file is called libelogind, not libsystemd or
+libsystemd-logind.
+
+The headers are in <elogind/...>, so like <elogind/sd-login.h> instead
+of <systemd/sd-login.h>.
+
+Libelogind just implements login-related functionality. It also
+provides the sd-bus API.
+
+Unlike systemd, whose logind arranges to manage resources for user
+sessions via RPC calls to systemd, in elogind there is no systemd so
+there is no global cgroup-based resource management. This has a few
+implications:
+
+ * Elogind does not create "slices" for users. Elogind will not
+ record that users are associated with slices.
+
+ * The /run/systemd/slices directory will always be empty.
+
+ * Elogind does not have the concept of a "scope", internally, as
+ it's the same as a session. Any API that refers to scopes will
+ always return an error code.
+
+On the other hand, elogind does use a similar strategy to systemd in
+that it places processes in a private cgroup for organizational
+purposes, without installing any controllers (see
+http://0pointer.de/blog/projects/cgroups-vs-cgroups.html). This
+allows elogind to map arbitrary processes to sessions, even if the
+process does the usual double-fork to be reparented to PID 1.
+
+Elogind does not manage virtual terminals.
+
+Elogind does monitor power button and the lid switch, like systemd,
+but instead of doing RPC to systemd to suspend, poweroff, or restart
+the machine, elogind just does this directly. For suspend, hibernate,
+and hybrid-sleep, elogind uses the same code as systemd-sleep.
+Instead of using a separate sleep.conf file to configure the sleep
+behavior, this is included in the [Sleep] section of
+/etc/elogind/login.conf. See the example login.conf for more. For
+shutdown, reboot, and kexec, elogind shells out to "halt", "reboot",
+and "kexec" binaries.
+
+The loginctl command has the poweroff, reboot, sleep, hibernate, and
+hybrid-sleep commands from systemd, as well as the --ignore-inhibitors
+flag.
+
+The PAM module is called pam_elogind.so, not pam_systemd.so.
+
+License
+-------
+
+LGPLv2.1+ for all code
+
+ - except src/shared/MurmurHash2.c which is Public Domain
+ - except src/shared/siphash24.c which is CC0 Public Domain
+ - except src/journal/lookup3.c which is Public Domain
+
+Dependencies
+------------
+
+ glibc >= 2.14
+ libcap
+ libmount >= 2.20 (from util-linux)
+ libseccomp >= 1.0.0 (optional)
+ libblkid >= 2.24 (from util-linux) (optional)
+ PAM >= 1.1.2 (optional)
+ libacl (optional)
+ libselinux (optional)
+ make, gcc, and similar tools
+
+During runtime, you need the following additional dependencies:
+
+ dbus >= 1.4.0 (strictly speaking optional, but recommended)
+ PolicyKit (optional)
+
+When building from git, you need the following additional
+dependencies:
+
+ pkg-config
+ docbook-xsl
+ xsltproc
+ automake
+ autoconf
+ libtool
+ intltool
+ gperf
+ gtkdocize (optional)
~ianmdlvl / elogind.git / blobdiff