file_manager: allow directories in "/etc/moonraker" to be registered

This may be useful for system packaging options that do not wish to put configuration in the home directory.

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

docs/configuration.md

@@ -44,12 +44,13 @@ config_path:
 #   The path to a directory where configuration files are located. This
 #   directory may contain Klipper config files (printer.cfg) or Moonraker
 #   config files (moonraker.conf).  Clients may also write their own config
-#   files to this directory.  This path must be located within the user's
-#   HOME directory, but may not be the home directory itself.  When this
-#   option is set the contents of the directory will be served to connected
-#   clients, allowing them to modify the various configuration files.  NOTE:
-#   If the config_path is not set, clients will not be able to save their
-#   UI configuration to disk.
+#   files to this directory.  There are restrictions on the location of
+#   this path, it must be located within the users HOME directory or within
+#   "/etc/moonraker".  The path may not be the HOME directory itself.  It is
+#   valid for the path to be "/etc/moonraker", however this is not recommended.
+#   Something like "/etc/moonraker/config" would be a more appropriate option.
+#   If you choose to locate files in "/etc/moonraker" be sure that Moonraker
+#   has read/write permissions in this directory.
 ```
 ## authorization
 

docs/installation.md

@@ -150,9 +150,14 @@ path: ~/gcode_files
 ```
 NOTES:
 - While Klipper does not set any hard limits on the location of the
-  `path` option for the `virtual_sdcard`, Moonraker requires that the path
-  be located within the HOME directory, it cannot however be the HOME
-  directory.  If you wish to host your files elsewhere, use a symlink.
+  `path` option for the `virtual_sdcard`, Moonraker does have specific
+  requirements for the location of this folder:
+  - It must be directory located in the HOME path or in `/etc/moonraker`
+  - It may not be the HOME directory itself.  It is ok for this folder
+    to be `/etc/moonraker`, however that is not recommended.  Something
+    like `/etc/moonraker/gcode_files` would be more appropriate.
+  - If you choose to place files in `/etc/moonraker` you must be sure that
+    Moonraker has permission to read/write to the directory.
 - Upon first starting Moonraker is not aware of the gcode file path, thus
   it cannot serve gcode files, add directories, etc.  After Klippy enters
   the "ready" state it sends Moonraker the gcode file path.

moonraker/plugins/file_manager.py

@@ -15,6 +15,7 @@ from tornado.locks import Event
 
 VALID_GCODE_EXTS = ['.gcode', '.g', '.gco']
 FULL_ACCESS_ROOTS = ["gcodes", "config"]
+ETC_DIR = "/etc/moonraker"
 METADATA_SCRIPT = os.path.normpath(os.path.join(
     os.path.dirname(__file__), "../../scripts/extract_metadata.py"))
 
@@ -85,8 +86,8 @@ class FileManager:
             return False
         home = os.path.expanduser('~')
         path = os.path.normpath(os.path.expanduser(path))
-        if not os.path.isdir(path) or not path.startswith(home) or \
-                path == home:
+        if not os.path.isdir(path) or path == home or \
+                not (path.startswith(home) or path.startswith(ETC_DIR)):
             logging.info(
                 f"\nSupplied path ({path}) for ({root}) not valid. Please\n"
                 "check that the path exists and is a subfolder in the HOME\n"