Fixes #38241 - Extend userdata API by MAC address endpoint

Make the Smart Proxy Userdata API endpoint consistent with
the Foreman API which was extended in #34887 (46ca3e70).

Author: Bastian Schmidt

modules/templates/templates_userdata_api.rb

@@ -8,4 +8,10 @@ class Proxy::TemplatesUserdataApi < Sinatra::Base
       Proxy::Templates::UserdataProxyRequest.new.get(kind, request.env, params)
     end
   end
+
+  get "/:mac/:kind" do |kind|
+    log_halt(500, "Failed to retrieve #{kind} userdata template for #{params.inspect}: ") do
+      Proxy::Templates::UserdataProxyRequest.new.get([mac, kind], request.env, params)
+    end
+  end
 end

test/templates/templates_userdata_api_test.rb

@@ -25,4 +25,11 @@ def test_api_can_ask_for_a_cloud_init_template
     assert last_response.ok?, "Last response was ok"
     assert_match("A user-data template", last_response.body)
   end
+
+  def test_api_can_ask_for_a_cloud_init_template_by_mac
+    stub_request(:get, "#{@foreman_url}/userdata/00:a1:b2:c3:d4:f5/user-data").with(query: {"url" => @template_url}).to_return(:body => 'A user-data template')
+    get "/00:a1:b2:c3:d4:f5/user-data", {}
+    assert last_response.ok?, "Last response was ok"
+    assert_match("A user-data template", last_response.body)
+  end
 end