env TORCHX_CONFIG for specified config (#504)

Summary:
Pull Request resolved: #504

design offline discussed

Reviewed By: dracifer

Differential Revision: D36692686

fbshipit-source-id: 1d7d8872f3562dba8c4dcfa00943e8cf98dff716

Author: Xiaolong Wang

torchx/runner/config.py

@@ -70,10 +70,9 @@
     $ torchx run -s local_cwd ./my_component.py:train
 
 #. In addition, it is possible to specify a different config other than .torchxconfig to
-   load at runtime. Requirements are that the config name is specified with a suffix and
-   passed as environment variable TORCHX_CONFIG_SUFFIX, and the .torchxconfig_${suffix}
-   resides in the current directory. It also disables hierarchy loading configs from
-   multiple directories as the case without specifying suffix.
+   load at runtime. Requirements are that the config path is specified by enviornment
+   variable TORCHX_CONFIG. It also disables hierarchy loading configs from multiple
+   directories as the cases otherwise.
 
 **Component Config**
 
@@ -153,7 +152,7 @@ def my_component(a: int) -> specs.AppDef:
 
 
 CONFIG_FILE = ".torchxconfig"
-ENV_TORCHX_CONFIG_SUFFIX = "TORCHX_CONFIG_SUFFIX"
+ENV_TORCHX_CONFIG = "TORCHX_CONFIG"
 CONFIG_PREFIX_DELIM = ":"
 
 _NONE = "None"
@@ -433,16 +432,16 @@ def get_config(
 def find_configs(dirs: Optional[Iterable[str]] = None) -> List[str]:
     """
     find_configs returns all the .torchxconfig files it finds:
-        - if environment variable TORCHX_CONFIG_SUFFIX is specified, then
-          ./torchxconfig_suffix is expected and will be loaded as the only config
+        - if environment variable TORCHX_CONFIG is specified, then
+          it is expected to exists and will be loaded as the only config
         - otherwise, directories are checked to look for .torchxconfig and loaded. If
           directories is empty it checks the local directory.
     """
 
     config_files = []
-    suffix = os.getenv(ENV_TORCHX_CONFIG_SUFFIX, "")
-    if len(suffix) > 0:
-        configfile = Path.cwd() / (CONFIG_FILE + "." + suffix)
+    config = os.getenv(ENV_TORCHX_CONFIG, "")
+    if len(config) > 0:
+        configfile = Path(config)
         assert configfile.exists(), f"{str(configfile)} expected but not found"
         config_files.append(str(configfile))
     else:

torchx/runner/test/config_test.py

@@ -186,7 +186,7 @@ def setUp(self) -> None:
             _MY_CONFIG,
         )
         self._write(
-            ".torchxconfig.suffixtest",
+            f"{self.test_dir}/another_torchx_config",
             _MY_CONFIG2,
         )
 
@@ -332,12 +332,12 @@ def test_apply_dirs(self, _) -> None:
         TORCHX_GET_SCHEDULERS,
         return_value={"test": TestScheduler()},
     )
-    def test_apply_from_suffix_config(self, _) -> None:
+    def test_apply_from_annotated_config(self, _) -> None:
         def mock_getenv(x: str, y: Optional[str] = None) -> Optional[str]:
-            if x != "TORCHX_CONFIG_SUFFIX":
+            if x != "TORCHX_CONFIG":
                 return os.environ.get(x, y)
             else:
-                return "suffixtest"
+                return f"{self.test_dir}/another_torchx_config"
 
         with patch(PATH_CWD, return_value=Path(self.test_dir)):
             with patch(