man: move "myhostname" right after "resolve"

The text in the man page provides the justification why I think this is
generally the right thing. An additional reason is that with the previous
commit (to move resolved earlier), since resolved internally implements the
same rules that nss-myhostname does, we'd have this strange inversion where
the priority of external configuration would be different in the "resolve"
path and in the fallback path.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2020-04-15 18:15:51 +02:00
parent 44b7aedbde
commit f2a20e9966
4 changed files with 13 additions and 6 deletions

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@ -67,9 +67,13 @@
<para>To activate the NSS modules, add <literal>myhostname</literal> to the line starting with
<literal>hosts:</literal> in <filename>/etc/nsswitch.conf</filename>.</para>
<para>It is recommended to place <literal>myhostname</literal> last in the <filename>nsswitch.conf</filename>'
<literal>hosts:</literal> line to make sure that this mapping is only used as fallback, and that any DNS or
<filename>/etc/hosts</filename> based mapping takes precedence.</para>
<para>It is recommended to place <literal>myhostname</literal> either between <literal>resolve</literal>
and "traditional" modules like <literal>files</literal> and <literal>dns</literal>, or after them. In the
first version, well-known names like <literal>localhost</literal> and the machine hostname are given
higher priority than the external configuration. This is recommended when the external DNS servers and
network are not absolutely trusted. In the second version, external configuration is given higher
priority and <command>nss-myhostname</command> only provides a fallback mechanism. This might be suitable
in closely controlled networks, for example on a company LAN.</para>
</refsect1>
<refsect1>
@ -83,6 +87,9 @@
group: compat mymachines systemd
shadow: compat
# Either (untrusted network):
hosts: mymachines resolve [!UNAVAIL=return] <command>myhostname</command> files dns
# Or (only trusted networks):
hosts: mymachines resolve [!UNAVAIL=return] files dns <command>myhostname</command>
networks: files

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@ -69,7 +69,7 @@
group: compat <command>mymachines</command> systemd
shadow: compat
hosts: <command>mymachines</command> resolve [!UNAVAIL=return] files dns myhostname
hosts: <command>mymachines</command> resolve [!UNAVAIL=return] myhostname files dns
networks: files
protocols: db files

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@ -67,7 +67,7 @@
group: compat mymachines systemd
shadow: compat
hosts: mymachines <command>resolve [!UNAVAIL=return]</command> files dns myhostname
hosts: mymachines <command>resolve [!UNAVAIL=return]</command> myhostname files dns
networks: files
protocols: db files

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@ -65,7 +65,7 @@
group: compat [SUCCESS=merge] mymachines [SUCCESS=merge] <command>systemd</command>
shadow: compat
hosts: mymachines resolve [!UNAVAIL=return] files dns myhostname
hosts: mymachines resolve [!UNAVAIL=return] myhostname files dns
networks: files
protocols: db files