Add command-line options to the command-line interface

These options will allow one to provide all required values as command-
line options. These options will also be the preferred source with any
environment variables being fallback options. This results in no impact
to how this project is currently run but allows for more convenient
usage on a local machine.

setup.py

@@ -92,6 +92,7 @@ def get_version(version_file):
     include_package_data=True,
     install_requires=[
         "Babel",
+        "docopt",
         "PyGithub",
         "python-dateutil",
         "pytimeparse",

src/apb/entrypoint.py

@@ -1,4 +1,29 @@
-"""GitHub Action to rebuild respositories that haven't been built in a while."""
+"""Tool to rebuild repositories that haven't been built in a while.
+
+This tool allows you to use environment variables to provide necessary information. Any
+options provided on the command-line will be used instead of any environment variables
+that have been set.
+
+Usage:
+  apb [--log-level <level>] [--github-token <token>] [--repo-query <query>] [--workflow-name <workflow>] [--build-age <age>] [--event-type >event>] [--max-rebuilds <limit>] [--output-dir <dir>] [--output-file <file>]
+
+Options:
+  --github-token <token>      The GitHub Personal Access Token to use for authentication.
+  --repo-query <query>        The query used to find GitHub repositories to check.
+  --workflow-name <workflow>  The name of the workflow that should be checked by the
+                              tool.
+  --build-age <age>           The maximum age of the last workflow run before a repository
+                              dispatch is created.
+  --event-type >event>        The type of event to send when a repository dispatch is
+                              created.
+  --max-rebuilds <limit>      The maximum number of rebuilds dispatches to create in a
+                              single run of the tool.
+  --output-dir <dir>          The directory that should house the created state file.
+  --output-file <file>        The name to use when creating the state file.
+  --log-level <level>         The log level to use if specified. Valid values are
+                              "debug", "info", "warning", "error", and "critical".
+                              [default: info]
+"""
 
 # Standard Python Libraries
 from datetime import datetime
@@ -7,16 +32,19 @@
 import os
 from pathlib import Path
 import sys
-from typing import Generator, Optional
+from typing import Dict, Generator, Optional
 
 # Third-Party Libraries
 from babel.dates import format_timedelta
 from dateutil.parser import isoparse
 from dateutil.relativedelta import relativedelta
+import docopt
 from github import Github, Repository
 import pytimeparse
 import requests
 
+from ._version import __version__
+
 
 def get_repo_list(
     g: Github, repo_query: str
@@ -50,18 +78,68 @@ def get_last_run(
 
 def main() -> None:
     """Parse evironment and perform requested actions."""
+    args: Dict[str, str] = docopt.docopt(__doc__, version=__version__)
+    # Get the list of logging levels supported by the logging library. Filter out
+    # values that are deprecated or not actual logging levels.
+    log_levels = [
+        level.lower()
+        for level in list(logging._nameToLevel.keys() - ["NOTSET", "WARN"])
+    ]
+    if args["--log-level"].lower() not in log_levels:
+        print(
+            "Possible values for --log-level are "
+            + ", ".join(log_levels[:-1])
+            + ", and "
+            + log_levels[-1],
+            file=sys.stderr,
+        )
+        sys.exit(-1)
     # Set up logging
-    logging.basicConfig(format="%(levelname)s %(message)s", level="INFO")
+    logging.basicConfig(
+        format="%(levelname)s %(message)s", level=args["--log-level"].upper()
+    )
 
     # Get inputs from the environment
-    access_token: Optional[str] = os.environ.get("INPUT_ACCESS_TOKEN")
-    build_age: Optional[str] = os.environ.get("INPUT_BUILD_AGE")
-    event_type: Optional[str] = os.environ.get("INPUT_EVENT_TYPE")
-    github_workspace_dir: Optional[str] = os.environ.get("GITHUB_WORKSPACE")
-    max_rebuilds: int = int(os.environ.get("INPUT_MAX_REBUILDS", 10))
-    repo_query: Optional[str] = os.environ.get("INPUT_REPO_QUERY")
-    workflow_id: Optional[str] = os.environ.get("INPUT_WORKFLOW_ID")
-    write_filename: Optional[str] = os.environ.get("INPUT_WRITE_FILENAME", "apb.json")
+    access_token: Optional[str] = (
+        args["--github-token"]
+        if args["--github-token"] is not None
+        else os.environ.get("INPUT_ACCESS_TOKEN")
+    )
+    build_age: Optional[str] = (
+        args["--build-age"]
+        if args["--build-age"] is not None
+        else os.environ.get("INPUT_BUILD_AGE")
+    )
+    event_type: Optional[str] = (
+        args["--event-type"]
+        if args["--event-type"] is not None
+        else os.environ.get("INPUT_EVENT_TYPE")
+    )
+    github_workspace_dir: Optional[str] = (
+        args["--output-dir"]
+        if args["--output-dir"] is not None
+        else os.environ.get("GITHUB_WORKSPACE")
+    )
+    max_rebuilds: int = int(
+        args["--max-rebuilds"]
+        if args["--max-rebuilds"] is not None
+        else os.environ.get("INPUT_MAX_REBUILDS", "10")
+    )
+    repo_query: Optional[str] = (
+        args["--repo-query"]
+        if args["--repo-query"] is not None
+        else os.environ.get("INPUT_REPO_QUERY")
+    )
+    workflow_id: Optional[str] = (
+        args["--workflow-name"]
+        if args["--workflow-name"] is not None
+        else os.environ.get("INPUT_WORKFLOW_ID")
+    )
+    write_filename: Optional[str] = (
+        args["--output-file"]
+        if args["--output-file"] is not None
+        else os.environ.get("INPUT_WRITE_FILENAME", "apb.json")
+    )
 
     # sanity checks
     if access_token is None: