enable local paths for experimental_index_url

Author: adrianimboden

python/private/pypi/simpleapi_download.bzl

@@ -217,14 +217,35 @@ def _read_simpleapi(ctx, url, attr, cache, get_auth = None, **download_kwargs):
 
     get_auth = get_auth or _get_auth
 
-    # NOTE: this may have block = True or block = False in the download_kwargs
-    download = ctx.download(
-        url = [real_url],
-        output = output,
-        auth = get_auth(ctx, [real_url], ctx_attr = attr),
-        allow_fail = True,
-        **download_kwargs
-    )
+    if not real_url.startswith("https://"):
+        normalized_url = real_url
+        local_path = ctx.path(normalized_url)
+
+        def local_read_index_result():
+            if local_path.is_dir:
+                ctx.file(output, ctx.read(normalized_url + "index.html"))
+                return struct(
+                    output = output,
+                    success = True,
+                )
+            else:
+                ctx.file(output, ctx.read(normalized_url))
+                return struct(
+                    output = output,
+                    success = True,
+                )
+
+        download = struct(wait = lambda: local_read_index_result())
+
+    else:
+        # NOTE: this may have block = True or block = False in the download_kwargs
+        download = ctx.download(
+            url = [real_url],
+            output = output,
+            auth = get_auth(ctx, [real_url], ctx_attr = attr),
+            allow_fail = False,
+            **download_kwargs
+        )
 
     if download_kwargs.get("block") == False:
         # Simulate the same API as ctx.download has

python/private/pypi/whl_library.bzl

@@ -295,12 +295,29 @@ def _whl_library_impl(rctx):
     elif rctx.attr.urls and rctx.attr.filename:
         filename = rctx.attr.filename
         urls = rctx.attr.urls
-        result = rctx.download(
-            url = urls,
-            output = filename,
-            sha256 = rctx.attr.sha256,
-            auth = get_auth(rctx, urls),
-        )
+        if len(urls) == 1 and not urls[0].startswith("https://"):
+            local_url = urls[0]
+            local_path = rctx.path(local_url)
+
+            if local_path.is_dir:
+                rctx.file(filename, rctx.read(local_url + "index.html"))
+                result = struct(
+                    output = filename,
+                    success = True,
+                )
+            else:
+                rctx.file(filename, rctx.read(local_url))
+                result = struct(
+                    output = filename,
+                    success = True,
+                )
+        else:
+            result = rctx.download(
+                url = urls,
+                output = filename,
+                sha256 = rctx.attr.sha256,
+                auth = get_auth(rctx, urls),
+            )
         if not rctx.attr.sha256:
             # this is only seen when there is a direct URL reference without sha256
             logger.warn("Please update the requirement line to include the hash:\n{} \\\n    --hash=sha256:{}".format(