Enforce read-only mode on import action

lib/flipper/ui/actions/import.rb

@@ -8,6 +8,7 @@ class Import < UI::Action
         route %r{\A/settings\/import/?\Z}
 
         def post
+          render_read_only if read_only?
           contents = params['file'][:tempfile].read
           export = Flipper::Exporters::Json::Export.new(contents: contents)
           flipper.import(export)

lib/flipper/ui/views/settings.erb

@@ -38,6 +38,7 @@
   </div>
 </div>
 
+<% if write_allowed? %>
 <div class="card">
   <div class="card-header">
     <h4 class="m-0">Import</h4>
@@ -51,3 +52,4 @@
     </form>
   </div>
 </div>
+<% end %>

spec/flipper/ui/actions/import_spec.rb

@@ -11,11 +11,12 @@
     { :csrf => token, 'csrf' => token, '_csrf_token' => token }
   end
 
+  let(:path) { FlipperRoot.join("spec", "fixtures", "flipper_pstore_1679087600.json") }
+
   describe "POST /settings/import" do
     before do
       flipper.enable :plausible
       flipper.disable :google_analytics
-      path = FlipperRoot.join("spec", "fixtures", "flipper_pstore_1679087600.json")
 
       post '/settings/import',
         {
@@ -37,5 +38,26 @@
       expect(last_response.status).to be(302)
       expect(last_response.headers['location']).to eq('/features')
     end
+
+    context "when in read only mode" do
+      before do
+        allow(flipper).to receive(:read_only?) { true }
+
+        post '/settings/import',
+          {
+            'authenticity_token' => token,
+            'file' => Rack::Test::UploadedFile.new(path, "application/json"),
+          },
+          'rack.session' => session
+      end
+
+      it 'returns 403' do
+        expect(last_response.status).to be(403)
+      end
+
+      it 'renders read only template' do
+        expect(last_response.body).to include('read only')
+      end
+    end
   end
 end