<filename>final.target</filename>,
<filename>getty.target</filename>,
<filename>graphical.target</filename>,
+ <filename>halt.target</filename>,
<filename>hibernate.target</filename>,
- <filename>http-daemon.target</filename>,
<filename>hybrid-sleep.target</filename>,
- <filename>halt.target</filename>,
<filename>kbrequest.target</filename>,
<filename>kexec.target</filename>,
<filename>local-fs.target</filename>,
units with a LSB header
referring to the
<literal>$x-display-manager</literal>
- facility, for compatibility
- with Debian.</para>
+ facility.</para>
</listitem>
</varlistentry>
<varlistentry>
<filename>sleep.target</filename>.</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><filename>http-daemon.target</filename></term>
- <listitem>
- <para>A target for pulling in
- an HTTP server if there is
- any.</para>
- <para>systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with a LSB header
- referring to the
- <literal>$httpd</literal>
- facility.</para>
- </listitem>
- </varlistentry>
<varlistentry>
<term><filename>hybrid-sleep.target</filename></term>
<listitem>
all SysV init script service
units with an LSB header
referring to the
- <literal>$mail-transfer-agent</literal>
- or
- <literal>$mail-transport-agent</literal>
- facilities, for compatibility
- with Debian.</para>
+ <literal>$mail-transfer-agent</literal>.</para>
</listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
<term><filename>runlevel2.target</filename></term>
- <listitem>
- <para>This is a target that is
- called whenever the SysV
- compatibility code asks for
- runlevel 2. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- <filename>multi-user.target</filename>.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
<term><filename>runlevel3.target</filename></term>
- <listitem>
- <para>This is a target that is
- called whenever the SysV
- compatibility code asks for
- runlevel 3. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- <filename>multi-user.target</filename>
- or
- <filename>graphical.target</filename>.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
<term><filename>runlevel4.target</filename></term>
- <listitem>
- <para>This is a target that is
- called whenever the SysV
- compatibility code asks for
- runlevel 4. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- <filename>multi-user.target</filename>
- or
- <filename>graphical.target</filename>.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
<term><filename>runlevel5.target</filename></term>
<listitem>
- <para>This is a target that is
- called whenever the SysV
+ <para>These are targets that
+ are called whenever the SysV
compatibility code asks for
- runlevel 5. It is a good idea
- to make this an alias for
+ runlevel 2, 3, 4, 5,
+ respectively. It is a good
+ idea to make this an alias for
(i.e. symlink to)
<filename>multi-user.target</filename>
- or
- <filename>graphical.target</filename>.</para>
+ (for runlevel 2) or
+ <filename>graphical.target</filename>
+ (the others).</para>
</listitem>
</varlistentry>
<varlistentry>
#define SPECIAL_RPCBIND_TARGET "rpcbind.target" /* LSB's $portmap */
#define SPECIAL_SYSLOG_TARGET "syslog.target" /* LSB's $syslog */
#define SPECIAL_TIME_SYNC_TARGET "time-sync.target" /* LSB's $time */
-#define SPECIAL_DISPLAY_MANAGER_SERVICE "display-manager.service" /* Debian's $x-display-manager */
-#define SPECIAL_MAIL_TRANSFER_AGENT_TARGET "mail-transfer-agent.target" /* Debian's $mail-{transport|transfer-agent */
-#define SPECIAL_HTTP_DAEMON_TARGET "http-daemon.target"
+#define SPECIAL_DISPLAY_MANAGER_SERVICE "display-manager.service" /* Common extension of LSB */
+#define SPECIAL_MAIL_TRANSFER_AGENT_TARGET "mail-transfer-agent.target" /* Common extension of LSB */
+
+/*
+ * Rules regarding adding further high level targets like the above:
+ *
+ * - Be conservative, only add more of these when we really need
+ * them. We need strong usecases for further additions.
+ *
+ * - When there can be multiple implementations running side-by-side,
+ * it needs to be a .target unit which can pull in all
+ * implementations.
+ *
+ * - If something can be implemented with socket activation, and
+ * without, it needs to be a .target unit, so that it can pull in
+ * the appropriate unit.
+ *
+ * - Otherwise, it should be a .service unit.
+ *
+ * - In some cases it is OK to have both a .service and a .target
+ * unit, i.e. if there can be multiple parallel implementations, but
+ * only one is the "system" one. Example: syslog.
+ *
+ * Or to put this in other words: .service symlinks can be used to
+ * arbitrate between multiple implementations if there can be only one
+ * of a kind. .target units can be used to support multiple
+ * implementations that can run side-by-side.
+ */
/* Magic early boot services */
#define SPECIAL_FSCK_SERVICE "systemd-fsck@.service"