Add basic plugin support (#609)

clowder/cli/__init__.py

@@ -14,6 +14,7 @@
 from clowder.cli.herd import add_herd_parser
 from clowder.cli.init import add_init_parser
 from clowder.cli.link import add_link_parser
+from clowder.cli.plugins import add_plugins_parser
 from clowder.cli.prune import add_prune_parser
 from clowder.cli.repo import add_repo_parser
 from clowder.cli.reset import add_reset_parser

clowder/cli/plugins.py

@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+"""Clowder command line plugins controller
+
+.. codeauthor:: Joe Decapo <joe@polka.cat>
+
+"""
+
+import argparse
+import os
+import importlib.util
+
+from clowder.environment import ENVIRONMENT
+from clowder.util.decorators import clowder_repo_required, valid_clowder_yaml_required
+
+from .util import add_parser_arguments
+
+
+def add_plugins_parser(subparsers: argparse._SubParsersAction) -> None:  # noqa
+    """Add clowder plugins parser
+
+    :param argparse._SubParsersAction subparsers: Subparsers action to add parser to
+    """
+
+    plugins_dir = ENVIRONMENT.clowder_repo_plugins_dir
+    if plugins_dir is None:
+        return
+    dir_exists = plugins_dir.exists()
+    is_dir = plugins_dir.is_dir()
+    if not dir_exists or not is_dir:
+        return
+
+    files = os.listdir(plugins_dir)
+    files = [ENVIRONMENT.clowder_repo_plugins_dir / f for f in files]
+    plugins = [f for f in files if f.is_dir()]
+    # TODO: Check for .py file
+    if not plugins:
+        return
+
+    for plugin in plugins:
+        # TODO: Add way to define help
+        parser = subparsers.add_parser(plugin.name, help=f"Run {plugin.name} command")
+        # parser.formatter_class = argparse.RawTextHelpFormatter
+        add_parser_arguments(parser, [])
+        parser.set_defaults(func=run)
+
+
+@clowder_repo_required
+@valid_clowder_yaml_required
+def run(args) -> None:
+    """Clowder plugins command private implementation"""
+
+    plugins_dir = ENVIRONMENT.clowder_repo_plugins_dir
+
+    plugin_name = args.subcommand
+    module = f"{plugin_name}.{plugin_name}"
+    module_file = plugins_dir / plugin_name / f"{plugin_name}.py"
+
+    # module = importlib.import_module(f"{plugin_name}.{plugin_name}")
+    # module.main()  # noqa
+
+    spec = importlib.util.spec_from_file_location(module, module_file)
+    plugin = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(plugin)  # noqa
+    plugin.main()  # noqa

clowder/clowder_app.py

@@ -57,7 +57,7 @@ def create_parsers() -> argparse.ArgumentParser:
             (['-v', '--version'], dict(action='version', version=version_message))
         ]
         cmd.add_parser_arguments(clowder_parser, arguments)
-        subparsers = clowder_parser.add_subparsers(help='sub-command help')
+        subparsers = clowder_parser.add_subparsers(dest='subcommand', help='sub-command help')
 
         cmd.add_branch_parser(subparsers)
         cmd.add_checkout_parser(subparsers)
@@ -68,6 +68,7 @@ def create_parsers() -> argparse.ArgumentParser:
         cmd.add_herd_parser(subparsers)
         cmd.add_init_parser(subparsers)
         cmd.add_link_parser(subparsers)
+        cmd.add_plugins_parser(subparsers)
         cmd.add_prune_parser(subparsers)
         cmd.add_repo_parser(subparsers)
         cmd.add_reset_parser(subparsers)

clowder/environment.py

@@ -22,6 +22,7 @@ class ClowderEnvironment(object):
     :cvar Optional[Path] clowder_dir: Path to clowder directory if it exists
     :cvar Optional[Path] clowder_repo_dir: Path to clowder repo directory if it exists
     :cvar Optional[Path] clowder_repo_versaions_dir: Path to clowder repo versions directory
+    :cvar Optional[Path] clowder_repo_plugins_dir: Path to clowder repo plugins directory
     :cvar Optional[Path] clowder_yaml: Path to clowder yaml file if it exists
     :cvar Optional[ClowderError] clowder_yaml_missing_source_error: Possible error for broken clowder yaml symlink
     :cvar Optional[ClowderError] ambiguous_clowder_yaml_error: Possible error due to ambiguous clowder yaml
@@ -35,6 +36,7 @@ class ClowderEnvironment(object):
     clowder_repo_dir: Optional[Path] = None
     clowder_git_repo_dir: Optional[Path] = None
     clowder_repo_versions_dir: Optional[Path] = None
+    clowder_repo_plugins_dir: Optional[Path] = None
     clowder_yaml: Optional[Path] = None
 
     clowder_yaml_missing_source_error: Optional[ClowderError] = None
@@ -119,6 +121,7 @@ def _configure_directories(self) -> None:
             self.clowder_repo_versions_dir: Optional[Path] = self.clowder_repo_dir / 'versions'
             self.clowder_config_dir: Optional[Path] = self.clowder_repo_dir / "config"
             self.clowder_config_yaml: Optional[Path] = self.clowder_config_dir / 'clowder.config.yml'
+            self.clowder_repo_plugins_dir: Optional[Path] = self.clowder_repo_dir / "plugins"
 
     def _get_possible_yaml_path(self, name: str) -> Path:
         """Get possible yaml path based on other environment variables