readonly s Hostname = '...';
readonly s StaticHostname = '...';
readonly s PrettyHostname = '...';
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("const")
+ readonly s FallbackHostname = '...';
+ readonly s HostnameSource = '...';
readonly s IconName = '...';
readonly s Chassis = '...';
readonly s Deployment = '...';
<variablelist class="dbus-property" generated="True" extra-ref="PrettyHostname"/>
+ <variablelist class="dbus-property" generated="True" extra-ref="FallbackHostname"/>
+
+ <variablelist class="dbus-property" generated="True" extra-ref="HostnameSource"/>
+
<variablelist class="dbus-property" generated="True" extra-ref="IconName"/>
<variablelist class="dbus-property" generated="True" extra-ref="Chassis"/>
<refsect1>
<title>Semantics</title>
- <para>The <emphasis>static (configured) hostname</emphasis> is the one configured in
- <filename>/etc/hostname</filename>. It is chosen by the local user. It is not always in sync with the
- current hostname as returned by the
+ <para>The <varname>StaticHostname</varname> property exposes the "static" hostname configured in
+ <filename>/etc/hostname</filename>. It is not always in sync with the current hostname as returned by the
<citerefentry project="man-pages"><refentrytitle>gethostname</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- system call. If no hostname is configured this property will be the empty string. Setting this property
- to the empty string will remove <filename>/etc/hostname</filename>. This property should be an
- internet-style hostname, 7-bit lowercase ASCII, no special chars/spaces.</para>
+ system call. If no static hostname is configured this property will be the empty string.</para>
- <para>The <emphasis>transient (dynamic) hostname</emphasis> is the one configured via the kernel's
+ <para>When <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> or
+ <citerefentry><refentrytitle>systemd-hostnamed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ set the hostname, this static hostname <emphasis>has the highest priority</emphasis>.</para>
+
+ <para>The <varname>Hostname</varname> property exposes the actual hostname configured in the kernel via
<citerefentry project="man-pages"><refentrytitle>sethostname</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
- It can be different from the static hostname if DHCP or mDNS have been configured to change the name
- based on network information. <!-- FIXME: it's not DHCP that configures this... -->
- This property is never empty. If no hostname is set this will default to
- <literal>&FALLBACK_HOSTNAME;</literal> (configurable at compilation time). Setting this property to the
- empty string will reset the dynamic hostname to the static hostname. If no static hostname is
- configured the dynamic hostname will be reset to <literal>&FALLBACK_HOSTNAME;</literal>. This property
- should be an internet-style hostname, 7-bit lowercase ASCII, no special chars/spaces.</para>
-
- <para>The <emphasis>pretty hostname</emphasis> is a free-form UTF-8 hostname for presentation to the
- user. User interfaces should ensure that the pretty hostname and the static hostname stay in sync.
- I.e. when the former is <literal>Lennart’s Computer</literal> the latter should be
- <literal>lennarts-computer</literal>. If no pretty hostname is set this setting will be the empty
- string. Applications should then find a suitable fallback, such as the dynamic hostname.</para>
-
- <para>The <emphasis>icon name</emphasis> is a name following the XDG icon naming spec. If not set,
- information such as the chassis type (see below) is used to find a suitable fallback icon name
- (i.e. <literal>computer-laptop</literal> vs. <literal>computer-desktop</literal> is picked based on the
- chassis information). If no such data is available, the empty string is returned. In that case an application
- should fall back to a replacement icon, for example <literal>computer</literal>. If this property is set
- to the empty string, the automatic fallback name selection is enabled again.</para>
-
- <para>The <emphasis>chassis type</emphasis> should be one of the currently defined chassis types:
- <literal>desktop</literal>, <literal>laptop</literal>, <literal>server</literal>,
- <literal>tablet</literal>, <literal>handset</literal>, as well as the special chassis types
- <literal>vm</literal> and <literal>container</literal> for virtualized systems. Note that in most cases
- the chassis type will be determined automatically from DMI/SMBIOS/ACPI firmware information. Writing to
- this setting is hence useful only to override misdetected chassis types, or to configure the chassis type if
- it could not be auto-detected. Set this property to the empty string to reenable the automatic detection of
- the chassis type from firmware information.</para>
+ It can be different from the static hostname. This property is never empty.</para>
+
+ <para>The <varname>PrettyHostname</varname> property exposes the <emphasis>pretty hostname</emphasis>
+ which is a free-form UTF-8 hostname for presentation to the user. User interfaces should ensure that the
+ pretty hostname and the static hostname stay in sync. E.g. when the former is <literal>Lennart’s
+ Computer</literal> the latter should be <literal>lennarts-computer</literal>. If no pretty hostname is
+ set this setting will be the empty string. Applications should then find a suitable fallback, such as the
+ dynamic hostname.</para>
+
+ <para>The <varname>FallbackHostname</varname> property exposes the fallback hostname (configured at
+ compilation time).</para>
+
+ <para>The <varname>HostnameSource</varname> property exposes the origin of the currently configured
+ hostname. One of <literal>static</literal> (set from <filename>/etc/hostname</filename>),
+ <literal>transient</literal> (a non-permanent hostname from an external source),
+ <literal>fallback</literal> (the compiled-in fallback value).</para>
+
+ <para>The <varname>IconName</varname> property exposes the <emphasis>icon name</emphasis> following the
+ XDG icon naming spec. If not set, information such as the chassis type (see below) is used to find a
+ suitable fallback icon name (i.e. <literal>computer-laptop</literal>
+ vs. <literal>computer-desktop</literal> is picked based on the chassis information). If no such data is
+ available, the empty string is returned. In that case an application should fall back to a replacement
+ icon, for example <literal>computer</literal>. If this property is set to the empty string, the automatic
+ fallback name selection is enabled again.</para>
+
+ <para>The <varname>Chassis</varname> property exposes a <emphasis>chassis type</emphasis>, one of the
+ currently defined chassis types: <literal>desktop</literal>, <literal>laptop</literal>,
+ <literal>server</literal>, <literal>tablet</literal>, <literal>handset</literal>, as well as the special
+ chassis types <literal>vm</literal> and <literal>container</literal> for virtualized systems. Note that
+ in most cases the chassis type will be determined automatically from DMI/SMBIOS/ACPI firmware
+ information. Writing to this setting is hence useful only to override misdetected chassis types, or to
+ configure the chassis type if it could not be auto-detected. Set this property to the empty string to
+ reenable the automatic detection of the chassis type from firmware information.</para>
<para>Note that <filename>systemd-hostnamed</filename> starts only on request and terminates after a
short idle period. This effectively means that <function>PropertyChanged</function> messages are not sent
out for changes made directly on the files (as in: administrator edits the files with vi). This is
the intended behavior: manual configuration changes should require manual reloading.</para>
- <para>The transient (dynamic) hostname maps directly to the kernel hostname. This hostname should be
- assumed to be highly dynamic, and hence should be watched directly, without depending on
- <function>PropertyChanged</function> messages from <filename>systemd-hostnamed</filename>. To accomplish
- this, open <filename>/proc/sys/kernel/hostname</filename> and
+ <para>The transient (dynamic) hostname exposed by the <varname>Hostname</varname> property maps directly
+ to the kernel hostname. This hostname should be assumed to be highly dynamic, and hence should be watched
+ directly, without depending on <function>PropertyChanged</function> messages from
+ <filename>systemd-hostnamed</filename>. To accomplish this, open
+ <filename>/proc/sys/kernel/hostname</filename> and
<citerefentry project="man-pages"><refentrytitle>poll</refentrytitle><manvolnum>3</manvolnum></citerefentry>
for <constant>SIGHUP</constant> which is triggered by the kernel every time the hostname changes. Again:
this is special for the transient (dynamic) hostname, and does not apply to the configured (fixed)
for that. For more information on these files and syscalls see the respective man pages.</para>
<refsect2>
- <title>Methods and Properties</title>
+ <title>Methods</title>
- <para><function>SetHostname()</function> sets the transient (dynamic) hostname which is exposed by the
- <varname>Hostname</varname> property. If empty, the transient hostname is set to the static hostname.
- </para>
+ <para><function>SetHostname()</function> sets the transient (dynamic) hostname, which is used if no
+ static hostname is set. This value must be an internet-style hostname, 7-bit lowercase ASCII, no
+ special chars/spaces. An empty string will unset the transient hostname.</para>
<para><function>SetStaticHostname()</function> sets the static hostname which is exposed by the
- <varname>StaticHostname</varname> property. If empty, the built-in default of
- <literal>&FALLBACK_HOSTNAME;</literal> is used.</para>
+ <varname>StaticHostname</varname> property. When called with an empty argument, the static
+ configuration in <filename>/etc/hostname</filename> is removed. Since the static hostname has the
+ highest priority, calling this function usually affects also the <varname>Hostname</varname> property
+ and the effective hostname configured in the kernel.</para>
<para><function>SetPrettyHostname()</function> sets the pretty hostname which is exposed by the
<varname>PrettyHostname</varname> property.</para>
with <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
- <para>A client that wants to change the local hostname for DHCP/mDNS should invoke
- <code>SetHostname("newname", false)</code> as soon as the name is available and afterwards reset it via
- <code>SetHostname("")</code>.</para>
-
<para>Here are some recommendations to follow when generating a static (internet) hostname from a pretty
name:
<itemizedlist>