Add ability to load config files, which are processed before command line arguments.

README.md

@@ -58,5 +58,8 @@ Image to create the container with (default: `debian:stable`)
 ### OW_CONTAINER
 Name to assign to container (default: `otherworld_$USER`)
 
+## Config Files
+Otherworld will look for config files named `.otherworld` in the current directory and all ancestor directories. Config files are Python scripts that can access and redefine the following variables: `command`, `user`, `uid`, `command_user`, `image_name`, `container_name`, `build_path`, `command_workdir`, `user_volumes`, `pull`, `command_env`. Config files are loaded in descending order (e.g. so `~/.otherworld` is loaded before `~/Projects/.otherworld`) and before command line arguments are processed. Additional variables available are `cwd` (the current directory), `config_file` (path to current configuration file) and `config_file_dir` (parent directory of config file)
+
 ## License
 [GNU GPL v3](https://www.gnu.org/licenses/gpl-3.0.en.html) or later

otherworld

@@ -10,6 +10,8 @@ CONTAINER_NAME = "otherworld"
 DEFAULT_IMAGE_NAME = "debian:stable"
 OTHERWORLD_LABEL = "otherworldowner"
 
+OTHERWORLD_CONFIG = ".otherworld"
+
 def create_x11_mapping ():
     home = os.environ["HOME"]
     xdg_dir = os.environ["XDG_RUNTIME_DIR"]
@@ -129,6 +131,32 @@ def expand_user_volumes (volumes):
 
     return mappings
 
+def find_config_files (config_name):
+    config_files = []
+    directory = os.path.abspath(os.getcwd())
+    while True:
+        config_file = os.path.join(directory, config_name)
+        if os.path.exists(config_file):
+            config_files.append(config_file)
+        
+        if directory == "/" or (not directory):
+            break
+        
+        directory = os.path.dirname(directory)
+    config_files.reverse()
+    return config_files
+
+def load_config_files (namespace, config_files):
+    config_keys = list(namespace.keys())
+    for config_file in config_files:
+        with open(config_file) as config_code:
+            namespace.update({
+                "config_file": config_file,
+                "config_file_dir": os.path.dirname(config_file)
+            })
+            exec(config_code.read(), {}, namespace)
+    return dict([item for item in namespace.items() if item[0] in config_keys])
+
 user = os.environ["USER"]
 uid = int(check_output(["id", "-u"]).strip())
 image_name = os.environ.get("OW_IMAGE", None)
@@ -146,6 +174,24 @@ command_env = {}
 command_workdir = None
 
 quiet = False
+
+# load config from files
+config = load_config_files({
+    "command": command,
+    "user": user,
+    "uid": uid,
+    "command_user": command_user,
+    "image_name": image_name,
+    "container_name": container_name,
+    "build_path": build_path,
+    "command_workdir": command_workdir,
+    "user_volumes": user_volumes,
+    "pull": pull,
+    "command_env": command_env,
+    "cwd": os.getcwd()
+}, find_config_files(OTHERWORLD_CONFIG))
+locals().update(config)
+
 while len(command) > 0:
     arg = command[0]
     if arg == "--quiet":