development/configd - add documentation for new config imports introduced in a1b0dd8071 , closes https://github.com/opnsense/docs/issues/532

source/development/backend/configd.rst

@@ -100,3 +100,35 @@ Next use the supplied helper command to execute our action:
 ::
 
     configctl sshd restart
+
+
+-----------------------------
+Extending the Environment
+-----------------------------
+
+Configd's own configuration can be found in the `configd.conf <https://github.com/opnsense/core/blob/master/src/opnsense/service/conf/configd.conf>`__ file.
+In some cases it can be practical to extend the envrionment with additional settings for the configd actions to use.
+
+To add environment variables, create a new config file in the :code:`conf/configd.conf.d/` directory
+using the :code:`.conf` extension containing an :code:`[environment]` section.
+For example, to add a proxy server (for the firmware updater), use settings like these:
+
+.. code-block::
+    :caption: /usr/local/opnsense/service/conf/configd.conf.d/proxy.conf
+
+    [environment]
+    HTTP_PROXY=http://proxy-adddress:8080
+    HTTPS_PROXY=http://proxy-adddress:8080
+
+
+
+.. Note::
+
+    After changing the configd configuration, don't forget to restart the configd service via the gui or `service configd restart` (as root).
+
+.. Warning::
+
+    When using the same settings as already specified in the base configuration, these settings will be overwritten. The parsing order
+    of configuration files is to read all vendor shipped properties first and read additional files next. Last property found is the one
+    being used (e.g. specifying a new :code:`PATH` in the environment, will overwrite the one being shipped in our :code:`configd.conf`.)
+

source/manual/firmware.rst

@@ -66,6 +66,13 @@ Usually the default options are good enough here, but if you want to choose a mi
     are planned for release. Just change the release type to **Development**.
 
 
+.. Note::
+
+    Although OPNsense does not support the configuration of a proxy server, for services like the firmware updater it is possible
+    to add these settings manually in our :code:`configd` service.
+    For more information we refer to :doc:`the envronment section in our development docs </development/backend/configd>`.
+
+
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