lcitool: Introduce a __main__ module

The thing with transitioning from setup.py to pyproject.toml build
strategy is that we now must specify a list of all entry points for the
project, IOW whatever is going to become the CLI executable. With
setup.py we got away by having a bin/lcitool script which would get
installed directly, but that's not how setuptools builds work after PEP
517 [1]. The build backend now creates the executables automatically as
wrappers over the entry points that are required to be listed in the
project's build config. There's one more requirement - the entry point
needs to be importable through Python's standard means. Since
bin/lcitool is not part of the lcitool package, hence not easily
importable as a module, we need to have its logic elsewhere. One of the
standard ways of doing that is by creating a __main__.py module which
python also automatically looks for when instructed to run the project
directly from its repo.

[1] https://peps.python.org/pep-0517/

Signed-off-by: Erik Skultety <eskultet@redhat.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/lcitool/__main__.py b/lcitool/__main__.py
new file mode 100644
index 0000000..a045e81
--- /dev/null
+++ b/lcitool/__main__.py
@@ -0,0 +1,41 @@
+import sys
+import logging
+
+from lcitool.application import Application
+from lcitool.commandline import CommandLine
+from lcitool.logger import LevelFormatter
+
+
+class LcitoolLogger(logging.Logger):
+    def debug(self, *args, **kwargs):
+        super().debug(*args, **kwargs, exc_info=True)
+
+
+def main():
+    log_level_formats = {
+        logging.DEBUG: "[%(levelname)s] %(module)s:%(funcName)s:%(lineno)d: %(message)s",
+        logging.ERROR: "[%(levelname)s]: %(message)s",
+    }
+
+    logging.setLoggerClass(LcitoolLogger)
+
+    custom_formatter = LevelFormatter(log_level_formats)
+    custom_handler = logging.StreamHandler(stream=sys.stderr)
+    custom_handler.setFormatter(custom_formatter)
+
+    log = logging.getLogger()
+    log.addHandler(custom_handler)
+
+    args = CommandLine().parse()
+
+    if args.debug:
+        log.setLevel(logging.DEBUG)
+
+    try:
+        Application().run(args)
+    except Exception:
+        log.exception("An unexpected error occurred")
+        sys.exit(1)
+
+
+main()