feat: add support for Go, Ruby, and NuGet modules with integration testing configurations

Signed-off-by: d9pouces <github@19pouces.net>

tests/dockerfiles/repos/build_test_nuget_feed.py

@@ -0,0 +1,61 @@
+"""Build a minimal NuGet v3 static feed around one real, `dotnet pack`-built
+.nupkg, for integration-testing the `nuget` module of id-configurator.
+
+Only two resources are populated: the flat container (`PackageBaseAddress`,
+used to enumerate versions and download the .nupkg directly) and the
+top-level service index pointing at it. `dotnet add package`/`dotnet
+restore` with an explicit, dependency-free package version only ever calls
+these two - never the (considerably more complex) registration resource -
+so it is intentionally not implemented here.
+
+The service index bakes in a __BASE_URL__ placeholder for its "@id" fields,
+since the host:port this fixture is actually reached on is only known once
+tox-docker starts the container, not at image-build time (see
+nuget-repo.nginx.conf). The flat container's own files never embed a URL,
+so they need no such rewriting.
+"""
+
+from __future__ import annotations
+
+import json
+import pathlib
+import shutil
+
+PACKAGE_ID = "idconfiguratortestpkg"
+VERSION = "0.0.1"
+NUPKG_NAME = f"{PACKAGE_ID}.{VERSION}.nupkg"
+NUPKG_SRC = pathlib.Path("/nupkg") / NUPKG_NAME
+OUT_DIR = pathlib.Path("/srv")
+
+
+def write_flat_container() -> None:
+    package_dir = OUT_DIR / "flatcontainer" / PACKAGE_ID
+    version_dir = package_dir / VERSION
+    version_dir.mkdir(parents=True, exist_ok=True)
+    (package_dir / "index.json").write_text(
+        json.dumps({"versions": [VERSION]}), encoding="utf-8"
+    )
+    shutil.copy(NUPKG_SRC, version_dir / NUPKG_NAME)
+
+
+def write_service_index() -> None:
+    index = {
+        "version": "3.0.0",
+        "resources": [
+            {
+                "@id": "__BASE_URL__/flatcontainer/",
+                "@type": "PackageBaseAddress/3.0.0",
+            }
+        ],
+    }
+    (OUT_DIR / "index.json").write_text(json.dumps(index), encoding="utf-8")
+
+
+def main() -> None:
+    OUT_DIR.mkdir(parents=True, exist_ok=True)
+    write_flat_container()
+    write_service_index()
+
+
+if __name__ == "__main__":
+    main()