add _late_args for later kernel_version

in cases where --kver is passed by cmdline (such as when used with
installkernel), validation could fail if there is no modules directory
before the config.toml is read where no_kmod may be set.

this allows for certain config to only be processed in the later stages
so cmdline args can be applied in the final config pass.

Signed-off-by: Zen <[email protected]>

Author: desultory

docs/dev_manual.md

@@ -10,6 +10,8 @@ Python functions can be added imported into `init` and `build` runlevels to exec
 
 Within modules, all config values are imported, then processed according to the order of the `custom_parameters` list.
 
+> If config values have validation which may fail if other config is not loaded, those values can be added to the `_late_args' list to be processed last.
+
 `_module_name` can be set within a module for logging purposes, it is verified to be accurate when imported but optional.
 
 ## Imports

src/ugrd/initramfs_dict.py

@@ -40,6 +40,7 @@ class InitramfsConfigDict(UserDict):
         "custom_parameters": dict,  # Custom parameters loaded from imports
         "custom_processing": dict,  # Custom processing functions which will be run to validate and process parameters
         "_processing": dict,  # A dict of queues containing parameters which have been set before the type was known
+        "_late_args": NoDupFlatList,  # A list of arguments which could be passed as command line args but need to be processed after the config is loaded
         "test_copy_config": NoDupFlatList,  # A list of config values which are copied into test images, from the parent
     }
 
@@ -57,7 +58,7 @@ def __init__(self, NO_BASE=False, *args, **kwargs):
         else:
             self["modules"] = "ugrd.base.core"
 
-    def import_args(self, args: dict, quiet=False) -> None:
+    def import_args(self, args: dict, quiet=False, late=False) -> None:
         """Imports data from an argument dict."""
         log_level = 10 if quiet else 20
         for arg, value in args.items():
@@ -66,6 +67,11 @@ def import_args(self, args: dict, quiet=False) -> None:
             if arg == "modules":  # allow loading modules by name from the command line
                 for module in value.split(","):
                     self[arg] = module
+            elif arg in self["_late_args"] and not late:
+                self.logger.debug(
+                    f"[{c_(arg, 'yellow')}] Deferring late argument processing until after config load: {c_(value, 'green')}",
+                )
+                continue
             elif getattr(self, arg, None) != value:  # Only set the value if it differs:
                 self[arg] = value
             else:

src/ugrd/initramfs_generator.py

@@ -31,7 +31,7 @@ def __init__(self, config="/etc/ugrd/config.toml", *args, **kwargs):
         try:  # Attempt to load the config file, if it exists
             self.load_config(config)  # The user config is loaded over the base config, clobbering kwargs
             self.config_dict.import_args(
-                kwargs, quiet=True
+                kwargs, quiet=True, late=True
             )  # Re-import kwargs (cmdline params) to apply them over the config
         except FileNotFoundError:
             if config:  # If a config file was specified, log an error that it's missing

src/ugrd/kmod/kmod.toml

@@ -3,6 +3,8 @@ modules = [ "ugrd.kmod.standard_mask", "ugrd.kmod.platform", "ugrd.kmod.input" ]
 kmod_pull_firmware = true
 kmod_decompress_firmware = true
 
+_late_args = ["kernel_version"]
+
 [custom_parameters]
 _kmod_removed = "NoDupFlatList"  # Meant to be used internally, defines kernel modules which have been ignored at runtime
 _kmod_modinfo = "dict" # Used internally, caches modinfo output for kernel modules