diff --git a/ROADMAP.md b/ROADMAP.md index 29260c7ab8..71553661a8 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -23,7 +23,7 @@ Docker Swarm Roadmap * [ ] Pluggable scheduler * [ ] Discovery backends * [x] etcd - * [ ] zookeeper + * [x] zookeeper * [x] consul * [x] hub * [x] file diff --git a/discovery/zookeeper/zookeeper.go b/discovery/zookeeper/zookeeper.go new file mode 100644 index 0000000000..67fda8d6d1 --- /dev/null +++ b/discovery/zookeeper/zookeeper.go @@ -0,0 +1,126 @@ +package zookeeper + +import ( + "path" + "strings" + "time" + + log "github.com/Sirupsen/logrus" + "github.com/docker/swarm/discovery" + "github.com/samuel/go-zookeeper/zk" +) + +type ZkDiscoveryService struct { + conn *zk.Conn + path string + heartbeat int +} + +func init() { + discovery.Register("zk", &ZkDiscoveryService{}) +} + +func (s *ZkDiscoveryService) Initialize(uris string, heartbeat int) error { + var ( + // split here because uris can contain multiples ips + // like `zk://192.168.0.1,192.168.0.2,192.168.0.3/path` + parts = strings.SplitN(uris, "/", 2) + ips = strings.Split(parts[0], ",") + ) + + conn, _, err := zk.Connect(ips, time.Second) + + if err != nil { + return err + } + + s.conn = conn + s.path = "/" + parts[1] + s.heartbeat = heartbeat + + _, err = conn.Create(s.path, []byte{1}, 0, zk.WorldACL(zk.PermAll)) + if err != nil { + // if key already existed, then skip + if err != zk.ErrNodeExists { + return err + } + } + + return nil +} + +func (s *ZkDiscoveryService) Fetch() ([]*discovery.Node, error) { + addrs, _, err := s.conn.Children(s.path) + + if err != nil { + return nil, err + } + + var nodes []*discovery.Node + for _, addr := range addrs { + nodes = append(nodes, discovery.NewNode(addr)) + } + + return nodes, nil +} + +func (s *ZkDiscoveryService) Watch(callback discovery.WatchCallback) { + + _, _, eventChan, err := s.conn.ChildrenW(s.path) + if err != nil { + log.Debugf("[ZK] Watch aborted") + return + } + + for e := range eventChan { + if e.Type == zk.EventNodeChildrenChanged { + log.Debugf("[ZK] Watch triggered") + nodes, err := s.Fetch() + if err == nil { + callback(nodes) + } + } + + } + +} + +func (s *ZkDiscoveryService) Register(addr string) error { + newpath := path.Join(s.path, addr) + + // check existing for the parent path first + exist, _, err := s.conn.Exists(s.path) + if err != nil { + return err + } + + // create parent first + if exist == false { + + _, err = s.conn.Create(s.path, []byte{1}, 0, zk.WorldACL(zk.PermAll)) + if err != nil { + return err + } + _, err = s.conn.Create(newpath, []byte(addr), 0, zk.WorldACL(zk.PermAll)) + return err + + } else { + + exist, _, err = s.conn.Exists(newpath) + if err != nil { + return err + } + + if exist { + err = s.conn.Delete(newpath, -1) + if err != nil { + return err + } + } + + _, err = s.conn.Create(newpath, []byte(addr), 0, zk.WorldACL(zk.PermAll)) + return err + } + + return nil +} diff --git a/discovery/zookeeper/zookeeper_test.go b/discovery/zookeeper/zookeeper_test.go new file mode 100644 index 0000000000..5e5a0b3258 --- /dev/null +++ b/discovery/zookeeper/zookeeper_test.go @@ -0,0 +1,16 @@ +package zookeeper + +import ( + "testing" + + "github.com/stretchr/testify/assert" +) + +func TestInitialize(t *testing.T) { + discovery := &ZkDiscoveryService{} + assert.Error(t, discovery.Initialize("127.0.0.1/path", 0)) + assert.Equal(t, discovery.path, "/path") + + assert.Error(t, discovery.Initialize("127.0.0.1,127.0.0.2,127.0.0.3/path", 0)) + assert.Equal(t, discovery.path, "/path") +} diff --git a/flags.go b/flags.go index a734d9a3f9..c97d19bdec 100644 --- a/flags.go +++ b/flags.go @@ -6,7 +6,7 @@ var ( flDiscovery = cli.StringFlag{ Name: "discovery", Value: "", - Usage: "DiscoveryService to use [token://, etcd://,/, file://path/to/file, consul:///]", + Usage: "DiscoveryService to use [token://, etcd://,/, file://path/to/file, consul:///, zk://,/]", EnvVar: "SWARM_DISCOVERY", } flAddr = cli.StringFlag{ diff --git a/main.go b/main.go index 4eb1d64a73..1965d24080 100644 --- a/main.go +++ b/main.go @@ -12,6 +12,7 @@ import ( _ "github.com/docker/swarm/discovery/etcd" _ "github.com/docker/swarm/discovery/file" "github.com/docker/swarm/discovery/token" + _ "github.com/docker/swarm/discovery/zookeeper" ) func main() {