picnoir
/
Systemd
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

man: add explanation where environment.d are inherited 

This is far from trivial, I guess.

Fixes #14714.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2020-02-28 10:56:38 +01:00
parent 07336a0672
commit 3ea2b1137b
1 changed files with 31 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
man/environment.d.xml
View File

@ -36,11 +36,11 @@
<refsect1>
<title>Description</title>
<para>The <filename>environment.d</filename> directories contain a list of "global" environment
variable assignments for the user environment.
<para>The <filename>environment.d</filename> directories contain a list of environment variable
assignments for services started by the systemd user instance.
<citerefentry><refentrytitle>systemd-environment-d-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
parses them and updates the environment exported by the systemd user instance to the services it
starts.</para>
parses them and updates the environment exported by the systemd user instance. See below for an
discussion of which processes inherit those variables.</para>
<para>It is recommended to use numerical prefixes for file names to simplify ordering.</para>
@ -89,6 +89,33 @@
</refsect2>
</refsect1>
<refsect1>
<title>Applicability</title>
<para>Environment variables exported by the user manager (<command>systemd --user</command> instance
started in the <filename>user@<replaceable>uid</replaceable>.service</filename> system service) apply to
any services started by that manager. In particular, this may include services which run user shells. For
example in the Gnome environment, the graphical terminal emulator runs as the
<filename>gnome-terminal-server.service</filename> user unit, which in turn runs the user shell, so that
shell will inherit environment variables exported by the user manager. For other instances of the shell,
not launched by the user manager, the environment they inherit is defined by the program that starts
them. Hint: in general,
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
units contain programs launched by systemd, and
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>
units contain programs launched by something else.</para>
<para>Specifically, for ssh logins, the
<citerefentry project='die-net'><refentrytitle>sshd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
service builds an environment that is a combination of variables forwarded from the remote system and
defined by <command>sshd</command>, see the discussion in
<citerefentry project='die-net'><refentrytitle>ssh</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
A graphical display session will have an analogous mechanism to define the environment. Note that some
managers query the systemd user instance for the exported environment and inject this configuration into
programs they start, using <command>systemctl show-environment</command> or the underlying D-Bus call.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>