feat: add bundler_remote attribute to rb_bundle_fetch (#81)

ruby/private/bundle_fetch.bzl

@@ -102,7 +102,10 @@ def _rb_bundle_fetch_impl(repository_ctx):
         srcs.append(src.name)
         repository_ctx.file(src.name, repository_ctx.read(src))
 
-    gemfile_lock = parse_gemfile_lock(repository_ctx.read(gemfile_lock_path))
+    gemfile_lock = parse_gemfile_lock(
+        repository_ctx.read(gemfile_lock_path),
+        repository_ctx.attr.bundler_remote,
+    )
     if not versions.is_at_least("2.2.19", gemfile_lock.bundler.version):
         fail(_OUTDATED_BUNDLER_ERROR)
 
@@ -198,6 +201,10 @@ rb_bundle_fetch = repository_rule(
         "env": attr.string_dict(
             doc = "Environment variables to use during installation.",
         ),
+        "bundler_remote": attr.string(
+            default = "https://rubygems.org/",
+            doc = "Remote to fetch the bundler gem from.",
+        ),
         "_build_tpl": attr.label(
             allow_single_file = True,
             default = "@rules_ruby//:ruby/private/bundle_fetch/BUILD.tpl",

ruby/private/bundle_fetch/gemfile_lock_parser.bzl

@@ -111,14 +111,15 @@ def _parse_git_package(lines):
 
     return {"revision": revision, "remote": remote}
 
-def parse_gemfile_lock(content):
+def parse_gemfile_lock(content, bundler_remote):
     """Parses a Gemfile.lock.
 
     Find lines in the content of a Gemfile.lock that look like package
     constraints.
 
     Args:
         content: Gemfile.lock contents
+        bundler_remote: Remote URL for the bundler package.
 
     Returns:
         struct with parsed Gemfile.lock
@@ -180,7 +181,7 @@ def parse_gemfile_lock(content):
                 version = version,
                 filename = "bundler-%s.gem" % version,
                 full_name = "bundler-%s" % version,
-                remote = "https://rubygems.org/",
+                remote = bundler_remote,
             )
             inside_bundled_with = False