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 } it "ignore_readonly returns nil from a pure exception" do result = DiscourseRedis.ignore_readonly { raise Redis::CommandError.new("READONLY") } expect(result).to eq(nil) end describe 'redis commands' do let(:raw_redis) { Redis.new(DiscourseRedis.config) } before do raw_redis.flushall end after do raw_redis.flushall end describe 'when namespace is enabled' do let(:redis) { DiscourseRedis.new } it 'should append namespace to the keys' do raw_redis.set('default:key', 1) raw_redis.set('test:key2', 1) expect(redis.keys).to include('key') expect(redis.keys).to_not include('key2') expect(redis.scan_each.to_a).to eq(['key']) redis.scan_each.each do |key| expect(key).to eq('key') end redis.del('key') expect(raw_redis.get('default:key')).to eq(nil) expect(redis.scan_each.to_a).to eq([]) raw_redis.set('default:key1', '1') raw_redis.set('default:key2', '2') expect(redis.mget('key1', 'key2')).to eq(['1', '2']) expect(redis.scan_each.to_a).to contain_exactly('key1', 'key2') end end describe 'when namespace is disabled' do let(:redis) { DiscourseRedis.new(nil, namespace: false) } it 'should not append any namespace to the keys' do raw_redis.set('default:key', 1) raw_redis.set('test:key2', 1) expect(redis.keys).to include('default:key', 'test:key2') redis.del('key') expect(raw_redis.get('key')).to eq(nil) raw_redis.set('key1', '1') raw_redis.set('key2', '2') expect(redis.mget('key1', 'key2')).to eq(['1', '2']) end it 'should noop a readonly redis' do expect(Discourse.recently_readonly?).to eq(false) redis.without_namespace .expects(:set) .raises(Redis::CommandError.new("READONLY")) redis.set('key', 1) expect(Discourse.recently_readonly?).to eq(true) end end end 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(:set).raises(Redis::CommandError.new("READONLY")) fallback_handler.expects(:verify_master).once $redis.set('test', '1') ensure fallback_handler.master = true $redis.del('test') end end end describe DiscourseRedis::Connector do let(:connector) { DiscourseRedis::Connector.new(config) } after do fallback_handler.master = true end it 'should return the master config when master is up' do expect(connector.resolve).to eq(config) end class BrokenRedis def initialize(error) @error = error end def call(*args) raise @error end def disconnect end end it 'should return the slave config when master is down' do error = Redis::CannotConnectError expect do connector.resolve(BrokenRedis.new(error)) end.to raise_error(Redis::CannotConnectError) config = connector.resolve expect(config[:host]).to eq(slave_host) expect(config[:port]).to eq(slave_port) end it "should return the slave config when master's hostname cannot be resolved" do error = RuntimeError.new('Name or service not known') expect do connector.resolve(BrokenRedis.new(error)) end.to raise_error(error) expect(fallback_handler.master).to eq(false) config = connector.resolve expect(config[:host]).to eq(slave_host) expect(config[:port]).to eq(slave_port) expect(fallback_handler.master).to eq(false) end it "should return the slave config when master is still loading data" do Redis::Client.any_instance .expects(:call) .with([:info]) .returns("someconfig:haha\r\nloading:1") config = connector.resolve expect(config[:host]).to eq(slave_host) expect(config[:port]).to eq(slave_port) end it "should raise the right error" do error = RuntimeError.new('test') 2.times do expect { connector.resolve(BrokenRedis.new(error)) } .to raise_error(error) end end end describe DiscourseRedis::FallbackHandler do before do @original_keepalive_interval = MessageBus.keepalive_interval end after do fallback_handler.master = true MessageBus.keepalive_interval = @original_keepalive_interval end describe '#initiate_fallback_to_master' do it 'should return the right value if the master server is still down' do fallback_handler.master = false Redis::Client.any_instance.expects(:call).with([:info]).returns("Some other stuff") expect(fallback_handler.initiate_fallback_to_master).to eq(false) expect(MessageBus.keepalive_interval).to eq(0) end it 'should fallback to the master server once it is up' do fallback_handler.master = false redis_connection = mock('test') Redis::Client.expects(:new).with(DiscourseRedis.slave_config).returns(redis_connection) redis_connection.expects(:call).with([:info]).returns(DiscourseRedis::FallbackHandler::MASTER_LINK_STATUS) DiscourseRedis::FallbackHandler::CONNECTION_TYPES.each do |connection_type| redis_connection.expects(:call).with([:client, [:kill, 'type', connection_type]]) end redis_connection.expects(:disconnect) expect(fallback_handler.initiate_fallback_to_master).to eq(true) expect(fallback_handler.master).to eq(true) expect(Discourse.recently_readonly?).to eq(false) expect(MessageBus.keepalive_interval).to eq(-1) end end end end