Support fsspec specifiers for ScriptCreator NBs

Addresses #42

Author: pont-us

docs/xcetool.md

@@ -13,9 +13,12 @@ details on usage and available options.
 
 Usage: `xcetool image build [OPTIONS] NOTEBOOK`
 
-This is the main `xcetool` subcommand: it builds a container image from a supplied
-notebook and environment file. If given the `--eoap` argument, it also generates
-a CWL file defining a corresponding application package.
+This is the main `xcetool` subcommand: it builds a container image from a
+supplied notebook and environment file. If given the `--eoap` argument, it also
+generates  a CWL file defining a corresponding application package. The
+NOTEBOOK argument can be a path to a local file, a URL, or any other string
+which can be parsed by the [fsspec](https://filesystem-spec.readthedocs.io/)
+library.
 
 Options:
 

environment.yml

@@ -18,6 +18,7 @@ dependencies:
   - cwltool
   - pytest
   - pytest-cov
+  - pytest-httpserver
   - pytz
 
 # Note: xcube is not required for the conversion itself, but is required

pyproject.toml

@@ -57,6 +57,7 @@ dev = [
   "cwltool",
   "pytest",
   "pytest-cov",
+  "pytest-httpserver",
   "pytz"
 ]
 doc = [

test/test_core.py

@@ -351,6 +351,16 @@ def test_script_creator_notebook_config():
     assert config["container_image_tag"] == "my-tag"
 
 
+def test_script_creator_notebook_config_http(httpserver):
+    http_path = "/mynotebook.ipynb"
+    nb_path = pathlib.Path(__file__).parent / "data" / "paramtest.ipynb"
+    httpserver.expect_request(http_path).respond_with_data(nb_path.read_bytes())
+    script_creator = ScriptCreator(httpserver.url_for(http_path))
+    config = script_creator.nb_params.config
+    assert config["environment_file"] == "my-environment.yml"
+    assert config["container_image_tag"] == "my-tag"
+
+
 def test_image_builder_notebook_config(tmp_path):
     nb_path = pathlib.Path(__file__).parent / "data" / "paramtest.ipynb"
     image_builder = ImageBuilder(nb_path, None, tmp_path, None)

xcengine/core.py

@@ -23,6 +23,7 @@
 from docker.errors import BuildError
 from docker.models.containers import Container
 from docker.models.images import Image
+import fsspec
 import nbconvert
 import nbformat
 import yaml
@@ -37,13 +38,19 @@
 class ScriptCreator:
     """Turn a Jupyter notebook into a set of scripts"""
 
-    nb_path: pathlib.Path
+    nb_path: pathlib.Path | str
     notebook: nbformat.NotebookNode
     nb_params: NotebookParameters = NotebookParameters({})
 
-    def __init__(self, nb_path: pathlib.Path):
+    def __init__(self, nb_path: pathlib.Path | str):
+        """
+        Instantiate a ScriptCreator for a specified notebook
+
+        :param nb_path: filesystem path or fsspec-parseable specifier
+          (e.g. HTTP URL) to the input notebook
+        """
         self.nb_path = nb_path
-        with open(nb_path) as fh:
+        with fsspec.open(str(nb_path)) as fh:
             self.notebook = nbformat.read(fh, as_version=4)
         self.process_params_cell()