refactor: port all sys.exit over to kas exceptions

This patch replaces all direct invocations of sys.exit outside of the
main invocation to KasUserError based exceptions. By that, only one
method for returning is used and return codes can be handled
consistently. In addition, this makes it possible to handle specific
errors differently.

Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

kas/plugins/build.py

@@ -40,6 +40,7 @@ from kas.config import Config
 from kas.libkas import find_program, run_cmd
 from kas.libcmds import Macro, Command
 from kas.libkas import setup_parser_common_args
+from kas.kasusererror import CommandExecError
 
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) Siemens AG, 2017-2018'
@@ -114,8 +115,7 @@ class BuildCommand(Command):
             logging.info('%s$ %s', ctx.build_dir, ' '.join(cmd))
             ret = subprocess.call(cmd, env=ctx.environ, cwd=ctx.build_dir)
             if ret != 0:
-                logging.error('Command returned non-zero exit status %d', ret)
-                sys.exit(ret)
+                raise CommandExecError(cmd, ret)
         else:
             run_cmd(cmd, cwd=ctx.build_dir)
 

kas/plugins/dump.py

@@ -63,7 +63,6 @@
     Note, that the lockfiles should be checked-in into the VCS.
 """
 
-import logging
 import sys
 import json
 import yaml
@@ -71,11 +70,17 @@ from typing import TypeVar, TextIO
 from collections import OrderedDict
 from kas.context import get_context
 from kas.plugins.checkout import Checkout
+from kas.kasusererror import KasUserError, ArgsCombinationError
 
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) Siemens AG, 2022'
 
 
+class OutputFormatError(KasUserError):
+    def __init__(self, format):
+        super().__init__('invalid format {}'.format(format))
+
+
 class IoTarget:
     StrOrTextIO = TypeVar('StrOrTextIO', str, TextIO)
 
@@ -184,8 +189,7 @@ class Dump(Checkout):
         output = IoTarget(target=sys.stdout, managed=False)
 
         if args.inplace and not args.lock:
-            logging.error('--inplace requires --lock')
-            sys.exit(1)
+            raise ArgsCombinationError('--inplace requires --lock')
 
         if args.lock:
             args.resolve_refs = True
@@ -220,8 +224,7 @@ class Dump(Checkout):
                     indent=args.indent,
                     Dumper=self.KasYamlDumper)
             else:
-                logging.error('invalid format %s', args.format)
-                sys.exit(1)
+                raise OutputFormatError(args.format)
 
 
 __KAS_PLUGINS__ = [Dump]

kas/plugins/for_all_repos.py

@@ -56,13 +56,13 @@
 import logging
 import os
 import subprocess
-import sys
 from kas.context import create_global_context
 from kas.config import Config
 from kas.libcmds import Macro, Command, SetupHome
 from kas.libkas import setup_parser_common_args
 from kas.libkas import setup_parser_preserve_env_arg
 from kas.libkas import run_handle_preserve_env_arg
+from kas.kasusererror import CommandExecError
 
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) Siemens AG, 2017-2018'
@@ -113,8 +113,7 @@ class ForAllReposCommand(Command):
             retcode = subprocess.call(self.command, shell=True, cwd=repo.path,
                                       env=env)
             if retcode != 0:
-                logging.error('Command failed with return code %d', retcode)
-                sys.exit(retcode)
+                raise CommandExecError(self.command, retcode)
 
 
 __KAS_PLUGINS__ = [ForAllRepos]

kas/plugins/menu.py

@@ -69,7 +69,6 @@
 import logging
 import os
 import pprint
-import sys
 import yaml
 from kconfiglib import Kconfig, Symbol, Choice, expr_value, TYPE_TO_STR, \
     MENU, COMMENT, STRING, BOOL, INT, HEX, UNKNOWN
@@ -78,6 +77,7 @@ 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
+from kas.kasusererror import KasUserError
 
 try:
     from snack import SnackScreen, EntryWindow, ButtonChoiceWindow, \
@@ -92,10 +92,18 @@ __copyright__ = \
     'Copyright (c) Siemens AG, 2021'
 
 
+class VariableTypeError(KasUserError):
+    pass
+
+
+class MissingModuleError(KasUserError):
+    pass
+
+
 def check_sym_is_string(sym):
     if sym.type != STRING:
-        logging.error('Variable %s must be of string type', sym.name)
-        sys.exit(1)
+        raise VariableTypeError('Variable {} must be of string type'
+                                .format(sym.name))
 
 
 def str_representer(dumper, data):
@@ -175,10 +183,9 @@ class Menu:
                 elif sym.type == HEX:
                     menu_configuration[symname] = int(symvalue, 16)
                 else:
-                    logging.error(
-                        'Configuration variable %s uses unsupported type',
-                        symname)
-                    sys.exit(1)
+                    raise VariableTypeError(
+                        'Configuration variable {} uses unsupported type'
+                        .format(symname))
 
             if symname.startswith('KAS_INCLUDE_'):
                 check_sym_is_string(sym)
@@ -241,9 +248,8 @@ class Menu:
 
     def run(self, args):
         if not newt_available:
-            logging.error(
+            raise MissingModuleError(
                 'Menu plugin requires \'python3-newt\' distribution package.')
-            sys.exit(1)
 
         ctx = create_global_context(args)
 

kas/plugins/shell.py

@@ -40,13 +40,13 @@
 import logging
 import os
 import subprocess
-import sys
 from kas.context import create_global_context
 from kas.config import Config
 from kas.libcmds import Macro, Command, SetupHome
 from kas.libkas import setup_parser_common_args
 from kas.libkas import setup_parser_preserve_env_arg
 from kas.libkas import run_handle_preserve_env_arg
+from kas.kasusererror import CommandExecError
 
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) Siemens AG, 2017-2018'
@@ -124,8 +124,8 @@ class ShellCommand(Command):
             cmd.append(self.cmd)
         ret = subprocess.call(cmd, env=ctx.environ, cwd=ctx.build_dir)
         if ret != 0:
-            logging.error('Shell returned non-zero exit status %d', ret)
-            sys.exit(ret)
+            logging.error('Shell returned non-zero exit status')
+            raise CommandExecError(cmd, ret, True)
 
 
 __KAS_PLUGINS__ = [Shell]