extract default values from schema

Instead of defining the default config values in the code, just use the
defaults provided in the schema. By that we also ensure that these are
consistent.

No functional change.

Signed-off-by: Felix Moessbauer <[email protected]>

kas/config.py

@@ -29,6 +29,7 @@
 from .repos import Repo
 from .includehandler import IncludeHandler, IncludeException
 from .kasusererror import ArtifactNotFoundError
+from .configschema import CONFIGSCHEMA
 
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) Siemens AG, 2017-2021'
@@ -162,7 +163,8 @@ def get_bitbake_targets(self):
                            if i]
         if environ_targets:
             return environ_targets
-        target = self._config.get('target', 'core-image-minimal')
+        def_target = CONFIGSCHEMA['properties']['target']['default']
+        target = self._config.get('target', def_target)
         if isinstance(target, str):
             return [target]
         return target
@@ -173,8 +175,9 @@ def get_bitbake_task(self):
         """
         if self._override_task:
             return self._override_task
+        default = CONFIGSCHEMA['properties']['task']['default']
         return os.environ.get('KAS_TASK',
-                              self._config.get('task', 'build'))
+                              self._config.get('task', default))
 
     def _get_conf_header(self, header_name):
         """
@@ -201,15 +204,17 @@ def get_machine(self):
         """
             Returns the machine
         """
+        default = CONFIGSCHEMA['properties']['machine']['default']
         return os.environ.get('KAS_MACHINE',
-                              self._config.get('machine', 'qemux86-64'))
+                              self._config.get('machine', default))
 
     def get_distro(self):
         """
             Returns the distro
         """
+        default = CONFIGSCHEMA['properties']['distro']['default']
         return os.environ.get('KAS_DISTRO',
-                              self._config.get('distro', 'poky'))
+                              self._config.get('distro', default))
 
     def get_environment(self):
         """