require 'rails_helper' describe DiscourseRedis do let(:slave_host) { 'testhost' } let(:slave_port) { 1234 } let(:config) do DiscourseRedis.config.dup.merge({ slave_host: 'testhost', slave_port: 1234, connector: DiscourseRedis::Connector }) end let(:fallback_handler) { DiscourseRedis::FallbackHandler.instance } context '.slave_host' do it 'should return the right config' do slave_config = DiscourseRedis.slave_config(config) expect(slave_config[:host]).to eq(slave_host) expect(slave_config[:port]).to eq(slave_port) end end context 'when redis connection is to a slave redis server' do it 'should check the status of the master server' do begin fallback_handler.master = false $redis.without_namespace.expects(:get).raises(Redis::CommandError.new("READONLY")) fallback_handler.expects(:verify_master).once $redis.get('test') ensure fallback_handler.master = true end end end describe DiscourseRedis::Connector do let(:connector) { DiscourseRedis::Connector.new(config) } it 'should return the master config when master is up' do expect(connector.resolve).to eq(config) end it 'should return the slave config when master is down' do begin Redis::Client.any_instance.expects(:call).raises(Redis::CannotConnectError).twice expect { connector.resolve }.to raise_error(Redis::CannotConnectError) config = connector.resolve expect(config[:host]).to eq(slave_host) expect(config[:port]).to eq(slave_port) ensure fallback_handler.master = true end end it "should return the slave config when master's hostname cannot be resolved" do begin error = RuntimeError.new('Name or service not known') Redis::Client.any_instance.expects(:call).raises(error).twice expect { connector.resolve }.to raise_error(error) config = connector.resolve expect(config[:host]).to eq(slave_host) expect(config[:port]).to eq(slave_port) ensure fallback_handler.master = true end end it "should raise the right error" do error = RuntimeError.new('test error') Redis::Client.any_instance.expects(:call).raises(error).twice 2.times { expect { connector.resolve }.to raise_error(error) } end end describe DiscourseRedis::FallbackHandler do describe '#initiate_fallback_to_master' do it 'should fallback to the master server once it is up' do begin fallback_handler.master = false Redis::Client.any_instance.expects(:call).with([:info]).returns(DiscourseRedis::FallbackHandler::MASTER_LINK_STATUS) Redis::Client.any_instance.expects(:call).with([:client, [:kill, 'type', 'normal']]) fallback_handler.initiate_fallback_to_master expect(fallback_handler.master).to eq(true) expect(Discourse.recently_readonly?).to eq(false) ensure fallback_handler.master = true end end end end end