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

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

id_configurator/modules/nuget.py

@@ -0,0 +1,66 @@
+"""Configure NuGet to use the configured NuGetRepository entries as its
+package sources, replacing the default (nuget.org).
+
+NuGet's own HTTPS client (.NET's HttpClient, backed by OpenSSL on Linux)
+already trusts whatever the `certificates` module installs into the system
+CA store, so no separate certificate configuration is needed here, unlike
+npm's.
+
+Microsoft documents a "Computer"-wide config file for this purpose,
+`/etc/opt/NuGet/Config` on Linux (or `$NUGET_COMMON_APPLICATION_DATA/NuGet/Config`
+should that variable be set) - but the .NET SDK does not actually read it in
+practice (confirmed empirically; a known, still-open upstream gap, see
+dotnet/sdk#12674), so it would silently have no effect. This instead writes
+the "user" level config, `~/.nuget/NuGet/NuGet.Config` (the location the
+.NET CLI itself uses; Mono/NuGet.exe use `~/.config/NuGet/NuGet.Config`
+instead). This tool targets Docker images, which are built and run as root,
+so `~` is assumed to be `/root`, exactly like a fresh dotnet install does
+when not overridden - the same tradeoff the `php` module's Composer config
+already accepts. A `<clear />` element is included so the configured
+sources fully replace nuget.org rather than being merged alongside it,
+matching every other package-manager module's behaviour.
+"""
+
+from __future__ import annotations
+
+import logging
+import xml.etree.ElementTree as ET
+
+from id_configurator.config import NuGetRepository
+from id_configurator.context import Context
+from id_configurator.modules.base import Module, register
+
+logger = logging.getLogger(__name__)
+
+_NUGET_CONFIG = "root/.nuget/NuGet/NuGet.Config"
+
+
+def _render_xml(root: ET.Element) -> bytes:
+    ET.indent(root)
+    content = '<?xml version="1.0" encoding="utf-8"?>\n' + ET.tostring(
+        root, encoding="unicode"
+    )
+    return (content + "\n").encode("utf-8")
+
+
+def _write_nuget_config(context: Context, repositories: list[NuGetRepository]) -> None:
+    configuration = ET.Element("configuration")
+    package_sources = ET.SubElement(configuration, "packageSources")
+    ET.SubElement(package_sources, "clear")
+    for repository in repositories:
+        ET.SubElement(
+            package_sources, "add", {"key": repository.name, "value": repository.url}
+        )
+    context.write_file(_NUGET_CONFIG, _render_xml(configuration))
+    logger.info("configured nuget to use %d package source(s)", len(repositories))
+
+
+@register
+class NuGetModule(Module):
+    name = "nuget"
+
+    def is_relevant(self, context: Context) -> bool:
+        return bool(context.config.configurations.nuget.repositories)
+
+    def apply(self, context: Context) -> None:
+        _write_nuget_config(context, context.config.configurations.nuget.repositories)