README.md

Curator Service Discovery (for Go)

Implement Curator-sytle service discovery in Go -- both server-side registration as well as client-side discovery.

Server-side

First, create teh service-discovery framework (passing it a connected curator) and call MaintainRegistrations() to start its connection monitor:

  s := discovery.NewServiceDiscovery(c, "/path/to/services")
  s.MaintainRegistrations()

Then register some services:

  reg := discovery.NewSimpleServiceInstance("baz", "127.0.0.1", 8080)
  ...
  if err := s.Register(reg); err != nil {
    log.Fatal("failed to register: ", err)
  }
  defer s.Unregister(reg)

Client-side

First, create a service-discovery framework (passing it a connected curator) and call Watch() to start watching for changes.

Use Provider(service) to get a provider, which can be used to get a registered instance (via GetInstance()) whenever one is needed.

The default strategy used when creating providers is to randomly select a registed node. Use ProviderWithStrategy(name, strategy) to pass a different ProviderStrategy, such as the RoundRobinProvider.

  s := discovery.NewServiceDiscovery(c, "/path/to/services")
  s.Watch()

  bazProvider := s.Provider("baz")
  ...

  def HandleReq() {
  ...
    hostForThisReq := bazProvider.GetInstance().Spec()
    http.Get(fmt.Sprintf("http://%s/path/to/resource", hostForThisReq))
  ...
  }

Testing

The tests use zk.StartTestCluster to get a testing zookeeper instance. This requires you have zookeeper installed locally (it searches a few relative and system paths). On OSX, brew install zookeeper is enough to get it working.

Authors

• David Taylor