[synapse] fix bug in generate_backend_stanze

lib/synapse/config_generator/haproxy.rb

@@ -1068,7 +1068,7 @@ def generate_backend_stanza(watcher, config)
 
       # The ordering here is important.  First we add all the backends in the
       # disabled state...
-      @state_cache.backends(watcher).each do |backend_name, backend|
+      @state_cache.backends(watcher.name).each do |backend_name, backend|
         backends[backend_name] = backend.merge('enabled' => false)
         # We remember the haproxy_server_id from a previous reload here.
         # Note though that if live servers below define haproxy_server_id

spec/lib/synapse/haproxy_spec.rb

@@ -481,6 +481,48 @@ class MockWatcher; end;
     expect(subject.generate_backend_stanza(mockwatcher, mockConfig)).to eql(["\nbackend example_service", [], ["\tserver somehost:5555 somehost:5555 id 1 cookie somehost:5555 check inter 2000 rise 3 fall 2"]])
   end
 
+  describe 'when known backend gets offline' do
+    let(:mockStateCache) do
+      mockCache = double(Synapse::ConfigGenerator::Haproxy::HaproxyState)
+      allow(mockCache).to receive(:backends).with(mockwatcher.name).and_return(
+        {
+          "somehost2:5555" => {
+            "host" => "somehost2",
+            "port" => 5555,
+            'haproxy_server_id' => 10,
+          }
+        }
+      )
+      mockCache
+    end
+
+    before do
+      allow(mockwatcher).to receive(:config_for_generator).and_return(
+        {
+          'haproxy' => {
+            'server_options' => "check inter 2000 rise 3 fall 2",
+            'backend_order' => 'no_shuffle',
+          }
+        }
+      )
+      subject.instance_variable_set(:@state_cache, mockStateCache)
+    end
+
+    it 'generates backend stanza with the disabled stat' do
+      mockConfig = ['mode tcp']
+      expect(subject.generate_backend_stanza(mockwatcher, mockConfig)).to eql(
+        [
+          "\nbackend example_service",
+          ["\tmode tcp"],
+          [
+            "\tserver somehost2:5555 somehost2:5555 id 10 check inter 2000 rise 3 fall 2 disabled",
+            "\tserver somehost:5555 somehost:5555 id 1 check inter 2000 rise 3 fall 2"
+          ]
+        ]
+      )
+    end
+  end
+
   describe 'generate backend stanza in correct order' do
     let(:multiple_backends_stanza_map) do
       {