Implements commands as extensions using stevedore; adds run and init command.

bonobo/__main__.py

@@ -0,0 +1,4 @@
+from bonobo.commands import entrypoint
+
+if __name__ == '__main__':
+    entrypoint()

bonobo/commands/__init__.py

@@ -0,0 +1,22 @@
+import argparse
+
+from stevedore import ExtensionManager
+
+
+def entrypoint():
+    parser = argparse.ArgumentParser()
+
+    subparsers = parser.add_subparsers(dest='command')
+    subparsers.required = True
+
+    def register_extension(ext):
+        parser = subparsers.add_parser(ext.name)
+        command = ext.plugin(parser)
+        parser.set_defaults(command=command)
+
+    mgr = ExtensionManager(namespace='bonobo.commands', )
+    mgr.map(register_extension)
+
+    args = parser.parse_args().__dict__
+    command = args.pop('command')
+    command(**args)

bonobo/commands/init.py

@@ -0,0 +1,18 @@
+import os
+
+
+def execute():
+    try:
+        import edgy.project
+    except ImportError as exc:
+        raise ImportError(
+            'You must install "edgy.project" to use this command.\n\n $ pip install edgy.project\n'
+        ) from exc
+
+    from edgy.project.__main__ import handle_init
+
+    return handle_init(os.path.join(os.getcwd(), 'Projectfile'))
+
+
+def register(parser):
+    return execute

bonobo/commands/run.py

@@ -0,0 +1,29 @@
+import argparse
+
+from bonobo import Graph, console_run
+
+
+def execute(file):
+    with file:
+        code = compile(file.read(), file.name, 'exec')
+
+    context = {}
+
+    try:
+        exec(code, context)
+    except Exception as exc:
+        raise
+
+    graphs = dict((k, v) for k, v in context.items() if isinstance(v, Graph))
+
+    assert len(graphs) == 1, 'Having more than one graph definition in one file is unsupported for now, but it is ' \
+                             'something that will be implemented in the future. '
+
+    name, graph = list(graphs.items())[0]
+
+    return console_run(graph)
+
+
+def register(parser):
+    parser.add_argument('file', type=argparse.FileType())
+    return execute

bonobo/util/helpers.py

@@ -1,8 +1,13 @@
 def run(*chain, plugins=None, strategy=None):
     from bonobo import Graph, ThreadPoolExecutorStrategy
 
-    graph = Graph()
-    graph.add_chain(*chain)
+    if len(chain) == 1 and isinstance(chain[0], Graph):
+        graph = chain[0]
+    elif len(chain) >= 1:
+        graph = Graph()
+        graph.add_chain(*chain)
+    else:
+        raise RuntimeError('Empty chain.')
 
     executor = (strategy or ThreadPoolExecutorStrategy)()
     return executor.execute(graph, plugins=plugins or [])