man: improve ManagerEnvironment documentation

- Improve wording for explanation when these variables are inherited

- Clarify that these variables are not placed in the process environment block,
  so /proc/PID/environ cannot be used as a debugging tool
This commit is contained in:
Vladimir Panteleev 2024-07-27 11:43:47 +00:00 committed by Luca Boccassi
parent 0462e902bf
commit 6c1e0823b0

View File

@ -474,10 +474,12 @@
<term><varname>ManagerEnvironment=</varname></term>
<listitem><para>Takes the same arguments as <varname>DefaultEnvironment=</varname>, see above. Sets
environment variables just for the manager process itself. In contrast to user managers, these variables
are not inherited by processes spawned by the system manager, use <varname>DefaultEnvironment=</varname>
environment variables for the manager process itself. These variables are inherited by processes
spawned by user managers, but not the system manager - use <varname>DefaultEnvironment=</varname>
for that. Note that these variables are merged into the existing environment block. In particular, in
case of the system manager, this includes variables set by the kernel based on the kernel command line.</para>
case of the system manager, this includes variables set by the kernel based on the kernel command line.
As with <varname>DefaultEnvironment=</varname>, this environment block is internal, and changes are not
reflected in the manager's <filename>/proc/PID/environ</filename>.</para>
<para>Setting environment variables for the manager process may be useful to modify its behaviour.
See <ulink url="https://systemd.io/ENVIRONMENT">Known Environment Variables</ulink> for a