Make dagster-images build work when it is called outside of a git repo (

#8088)

Summary:
Right now there's a requirement that when you run this command you have the automation library checked out in a github repo. The release pipeline will break that requirement once it is running from a Docker image. So instead figure out where the code is to copy based on the current github repository, rather than assuming a fixed file relative to the python file running the command.

Test Plan:
BK

python_modules/automation/automation/docker/dagster_docker.py

@@ -6,6 +6,7 @@
 
 import dagster._check as check
 
+from ..git import git_repo_root
 from .ecr import ecr_image, get_aws_account_id, get_aws_region
 from .utils import (
     execute_docker_build,
@@ -26,28 +27,57 @@ def do_nothing(_cwd: str) -> Iterator[None]:
     yield
 
 
+def default_images_path():
+    return os.path.join(
+        git_repo_root(),
+        "python_modules",
+        "automation",
+        "automation",
+        "docker",
+        "images",
+    )
+
+
 class DagsterDockerImage(
-    NamedTuple("_DagsterDockerImage", [("image", str), ("build_cm", Callable), ("path", str)])
+    NamedTuple(
+        "_DagsterDockerImage",
+        [
+            ("image", str),
+            ("images_path", str),
+            ("build_cm", Callable),
+        ],
+    )
 ):
     """Represents a Dagster image.
 
     Properties:
         image (str): Name of the image
+        images_path (Optional(str)): The base folder for the images.
         build_cm (function): function that is a context manager for build (e.g. for populating a
             build cache)
-        path (Optional(str)): The path to the image's path. Defaults to docker/images/<IMAGE NAME>
     """
 
-    def __new__(cls, image: str, build_cm: Callable = do_nothing, path: Optional[str] = None):
+    def __new__(
+        cls,
+        image: str,
+        images_path: Optional[str] = None,
+        build_cm: Callable = do_nothing,
+    ):
         return super(DagsterDockerImage, cls).__new__(
             cls,
             check.str_param(image, "image"),
-            check.callable_param(build_cm, "build_cm"),
             check.opt_str_param(
-                path, "path", default=os.path.join(os.path.dirname(__file__), "images", image)
+                images_path,
+                "images_path",
+                default_images_path(),
             ),
+            check.callable_param(build_cm, "build_cm"),
         )
 
+    @property
+    def path(self) -> str:
+        return os.path.join(self.images_path, self.image)
+
     @property
     def python_versions(self) -> List[str]:
         """List of Python versions supported for this image."""
@@ -130,7 +160,9 @@ def _get_docker_args(self, dagster_version: str, python_version: str) -> Dict[st
                 "BASE_IMAGE" not in docker_args, "Cannot override an existing BASE_IMAGE"
             )
 
-            base_image = DagsterDockerImage(image_info["base_image"]["name"])
+            base_image = DagsterDockerImage(
+                image_info["base_image"]["name"], images_path=self.images_path
+            )
             source = image_info["base_image"]["source"]
 
             if source == "aws":

python_modules/automation/automation/docker/image_defs.py

@@ -8,7 +8,7 @@
 
 import dagster._check as check
 
-from .dagster_docker import DagsterDockerImage
+from .dagster_docker import DagsterDockerImage, default_images_path
 
 
 def get_dagster_repo() -> str:
@@ -207,12 +207,12 @@ def list_images(images_path: Optional[str] = None) -> List[DagsterDockerImage]:
         List[DagsterDockerImage]: A list of all images managed by this tool.
     """
 
-    images_path = images_path or os.path.join(os.path.dirname(__file__), "images")
+    images_path = images_path or default_images_path()
     image_folders = [f.name for f in os.scandir(images_path) if f.is_dir()]
 
     images = []
     for image in image_folders:
-        img = DagsterDockerImage(image, path=os.path.join(images_path, image))
+        img = DagsterDockerImage(image, images_path=images_path)
         if image in CUSTOM_BUILD_CONTEXTMANAGERS:
             img = img._replace(build_cm=CUSTOM_BUILD_CONTEXTMANAGERS[image])
         images.append(img)

python_modules/automation/automation_tests/docker_tests/test_dagster_docker.py

@@ -12,5 +12,6 @@ def test_image_path():
         "docker",
         "images",
     )
-    assert DagsterDockerImage("foo").path == os.path.join(default_images_path, "foo")
-    assert DagsterDockerImage("foo", path="bar").path == "bar"
+    assert DagsterDockerImage("foo", default_images_path).path == os.path.join(
+        default_images_path, "foo"
+    )

python_modules/automation/automation_tests/docker_tests/test_image_defs.py

@@ -69,13 +69,13 @@ def test_get_image(tmpdir):
     assert get_image("k8s-example")
 
     with pytest.raises(Exception) as e:
-        get_image("hello-world", images_path=tmpdir)
+        get_image("hello-world", images_path=str(tmpdir))
     assert "could not find image hello-world" in str(e.value)
 
     hello_world = tmpdir / "hello-world"
     hello_world.mkdir()
     (hello_world / "Dockerfile").write("FROM hello-world")
 
-    image = get_image("hello-world", images_path=tmpdir)
+    image = get_image("hello-world", images_path=str(tmpdir))
     assert image.image == "hello-world"
     assert image.path == hello_world