Fall back to .config.yaml if no configuration file given

Make the configuration file on the command line optional and fall back
to trying to open the generated .config.yaml instead. This allows the
sequence

kas menu -> save & exit
kas build
kas shell
kas ...

and also makes rebuilding the self-configured image simpler.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

kas-container

@@ -29,8 +29,8 @@ set -e
 
 usage()
 {
-	printf "%b" "Usage: $0 [OPTIONS] { build | checkout | shell } [KASOPTIONS] KASFILE\n"
-	printf "%b" "       $0 [OPTIONS] for-all-repos [KASOPTIONS] KASFILE COMMAND\n"
+	printf "%b" "Usage: $0 [OPTIONS] { build | checkout | shell } [KASOPTIONS] [KASFILE]\n"
+	printf "%b" "       $0 [OPTIONS] for-all-repos [KASOPTIONS] [KASFILE] COMMAND\n"
 	printf "%b" "       $0 [OPTIONS] clean\n"
 	printf "%b" "\nPositional arguments:\n"
 	printf "%b" "build\t\t\tCheck out repositories and build target.\n"
@@ -288,7 +288,15 @@ while [ $# -gt 0 ] && [ $KAS_EXTRA_BITBAKE_ARGS -eq 0 ]; do
 	esac
 done
 
-[ -n "${KAS_FIRST_FILE}" ] || usage
+if [ -n "${KAS_FIRST_FILE}" ]; then
+	KAS_FILE_DIR="$(dirname "${KAS_FIRST_FILE}")"
+	KAS_REPO_DIR=$(git -C "${KAS_FILE_DIR}" rev-parse --show-toplevel 2>/dev/null) \
+		|| KAS_REPO_DIR=$(hg --cwd "${KAS_FILE_DIR}" root 2>/dev/null) \
+		|| KAS_REPO_DIR=${KAS_FILE_DIR}
+else
+	KAS_FIRST_FILE="${KAS_WORK_DIR}/.config.yaml"
+	KAS_REPO_DIR=$(pwd)
+fi
 
 BUILD_SYSTEM=$(grep -e "^build_system: " "${KAS_FIRST_FILE}" 2>/dev/null | sed 's/build_system:[ ]\+//')
 if [ "${BUILD_SYSTEM}" = "isar" ]; then
@@ -297,12 +305,6 @@ fi
 
 set_container_image_var
 
-KAS_FILE_DIR="$(dirname "${KAS_FIRST_FILE}")"
-
-KAS_REPO_DIR=$(git -C "${KAS_FILE_DIR}" rev-parse --show-toplevel 2>/dev/null) \
-	|| KAS_REPO_DIR=$(hg --cwd "${KAS_FILE_DIR}" root 2>/dev/null) \
-	|| KAS_REPO_DIR=${KAS_FILE_DIR}
-
 KAS_REPO_MOUNT_OPT="${KAS_REPO_MOUNT_OPT:-${KAS_REPO_MOUNT_OPT_DEFAULT}}"
 
 KAS_FILES="$(echo "${KAS_FILES}" | sed 's|'"${KAS_REPO_DIR}"'/|/repo/|g')"

kas/config.py

@@ -30,6 +30,8 @@ from .includehandler import IncludeHandler, IncludeException
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) Siemens AG, 2017-2021'
 
+CONFIG_YAML_FILE = '.config.yaml'
+
 
 class Config:
     """
@@ -39,6 +41,7 @@ class Config:
         self._override_target = target
         self._override_task = task
         self._config = {}
+        if filename:
             self.filenames = [os.path.abspath(configfile)
                               for configfile in filename.split(':')]
             self.top_repo_path = Repo.get_root_path(
@@ -47,10 +50,14 @@ class Config:
             repo_paths = [Repo.get_root_path(os.path.dirname(configfile),
                                              fallback=False)
                           for configfile in self.filenames]
+
             if len(set(repo_paths)) > 1:
                 raise IncludeException('All concatenated config files must '
                                        'belong to the same repository or all '
                                        'must be outside of versioning control')
+        else:
+            self.filenames = [os.path.join(ctx.kas_work_dir, CONFIG_YAML_FILE)]
+            self.top_repo_path = os.getcwd()
 
         self.handler = IncludeHandler(self.filenames, self.top_repo_path)
         self.repo_dict = self._get_repo_dict()

kas/libkas.py

@@ -363,7 +363,10 @@ def ssh_no_host_key_check():
 
 def setup_parser_common_args(parser):
     parser.add_argument('config',
-                        help='Config file')
+                        help='Config file, using .config.yaml if none is '
+                        'specified and using the current directory as '
+                        'repository anchor',
+                        nargs='?')
     parser.add_argument('--skip',
                         help='Skip build steps',
                         default=[])

kas/plugins/menu.py

@@ -75,6 +75,7 @@ from kconfiglib import Kconfig, Symbol, Choice, expr_value, TYPE_TO_STR, \
     MENU, COMMENT, STRING, BOOL, INT, HEX, UNKNOWN
 from kas import __version__, __file_version__
 from kas.context import create_global_context
+from kas.config import CONFIG_YAML_FILE
 from kas.includehandler import load_config as load_config_yaml
 from kas.plugins.build import Build
 
@@ -90,8 +91,6 @@ __copyright__ = \
     'Copyright (c) 2011-2019, Ulf Magnusson <ulfalizer@gmail.com>\n' \
     'Copyright (c) Siemens AG, 2021'
 
-CONFIG_YAML_FILE = '.config.yaml'
-
 
 def check_sym_is_string(sym):
     if sym.type != STRING: