Merge pull request #851 from aluzzardi/discovery-prefix

discovery: KV Path is now an optional prefix.

discovery/kv/kv.go

@@ -11,13 +11,17 @@ import (
 	"github.com/docker/swarm/pkg/store"
 )
 
+const (
+	discoveryPath = "docker/swarm/nodes"
+)
+
 // Discovery is exported
 type Discovery struct {
 	backend   store.Backend
 	store     store.Store
 	heartbeat time.Duration
 	ttl       time.Duration
-	prefix    string
+	path      string
 }
 
 func init() {
@@ -35,22 +39,19 @@ func Init() {
 func (s *Discovery) Initialize(uris string, heartbeat time.Duration, ttl time.Duration) error {
 	var (
 		parts  = strings.SplitN(uris, "/", 2)
-		ips   = strings.Split(parts[0], ",")
+		addrs  = strings.Split(parts[0], ",")
-		addrs []string
+		prefix = ""
 		err    error
 	)
 
-	if len(parts) != 2 {
+	// A custom prefix to the path can be optionally used.
-		return fmt.Errorf("invalid format %q, missing <path>", uris)
+	if len(parts) == 2 {
-	}
+		prefix = parts[1]
-
-	for _, ip := range ips {
-		addrs = append(addrs, ip)
 	}
 
 	s.heartbeat = heartbeat
 	s.ttl = ttl
-	s.prefix = parts[1]
+	s.path = path.Join(prefix, discoveryPath)
 
 	// Creates a new store, will ignore options given
 	// if not supported by the chosen store
@@ -108,7 +109,7 @@ func (s *Discovery) Watch(stopCh <-chan struct{}) (<-chan discovery.Entries, <-c
 		// Will only stop if we receive a stopCh request.
 		for {
 			// Set up a watch.
-			watchCh, err := s.store.WatchTree(s.prefix, stopCh)
+			watchCh, err := s.store.WatchTree(s.path, stopCh)
 			if err != nil {
 				errCh <- err
 			} else {
@@ -129,7 +130,7 @@ func (s *Discovery) Watch(stopCh <-chan struct{}) (<-chan discovery.Entries, <-c
 // Register is exported
 func (s *Discovery) Register(addr string) error {
 	opts := &store.WriteOptions{Ephemeral: true, Heartbeat: s.heartbeat}
-	return s.store.Put(path.Join(s.prefix, addr), []byte(addr), opts)
+	return s.store.Put(path.Join(s.path, addr), []byte(addr), opts)
 }
 
 // Store returns the underlying store used by KV discovery.

discovery/kv/kv_test.go

@@ -2,6 +2,7 @@ package kv
 
 import (
 	"errors"
+	"path"
 	"testing"
 	"time"
 
@@ -13,14 +14,18 @@ import (
 
 func TestInitialize(t *testing.T) {
 	d := &Discovery{backend: store.MOCK}
-	assert.EqualError(t, d.Initialize("127.0.0.1", 0, 0), "invalid format \"127.0.0.1\", missing <path>")
+	assert.NoError(t, d.Initialize("127.0.0.1", 0, 0))
+	s := d.store.(*store.Mock)
+	assert.Len(t, s.Endpoints, 1)
+	assert.Equal(t, s.Endpoints[0], "127.0.0.1")
+	assert.Equal(t, d.path, discoveryPath)
 
 	d = &Discovery{backend: store.MOCK}
 	assert.NoError(t, d.Initialize("127.0.0.1:1234/path", 0, 0))
-	s := d.store.(*store.Mock)
+	s = d.store.(*store.Mock)
 	assert.Len(t, s.Endpoints, 1)
 	assert.Equal(t, s.Endpoints[0], "127.0.0.1:1234")
-	assert.Equal(t, d.prefix, "path")
+	assert.Equal(t, d.path, "path/"+discoveryPath)
 
 	d = &Discovery{backend: store.MOCK}
 	assert.NoError(t, d.Initialize("127.0.0.1:1234,127.0.0.2:1234,127.0.0.3:1234/path", 0, 0))
@@ -29,7 +34,7 @@ func TestInitialize(t *testing.T) {
 	assert.Equal(t, s.Endpoints[0], "127.0.0.1:1234")
 	assert.Equal(t, s.Endpoints[1], "127.0.0.2:1234")
 	assert.Equal(t, s.Endpoints[2], "127.0.0.3:1234")
-	assert.Equal(t, d.prefix, "path")
+	assert.Equal(t, d.path, "path/"+discoveryPath)
 }
 
 func TestWatch(t *testing.T) {
@@ -40,16 +45,16 @@ func TestWatch(t *testing.T) {
 	mockCh := make(chan []*store.KVPair)
 
 	// The first watch will fail.
-	s.On("WatchTree", "path", mock.Anything).Return(mockCh, errors.New("test error")).Once()
+	s.On("WatchTree", "path/"+discoveryPath, mock.Anything).Return(mockCh, errors.New("test error")).Once()
 	// The second one will succeed.
-	s.On("WatchTree", "path", mock.Anything).Return(mockCh, nil).Once()
+	s.On("WatchTree", "path/"+discoveryPath, mock.Anything).Return(mockCh, nil).Once()
 	expected := discovery.Entries{
 		&discovery.Entry{Host: "1.1.1.1", Port: "1111"},
 		&discovery.Entry{Host: "2.2.2.2", Port: "2222"},
 	}
 	kvs := []*store.KVPair{
-		{Key: "path/1.1.1.1", Value: []byte("1.1.1.1:1111")},
+		{Key: path.Join("path", discoveryPath, "1.1.1.1"), Value: []byte("1.1.1.1:1111")},
-		{Key: "path/1.1.1.1", Value: []byte("2.2.2.2:2222")},
+		{Key: path.Join("path", discoveryPath, "2.2.2.2"), Value: []byte("2.2.2.2:2222")},
 	}
 
 	stopCh := make(chan struct{})
@@ -69,13 +74,13 @@ func TestWatch(t *testing.T) {
 
 	// Add a new entry.
 	expected = append(expected, &discovery.Entry{Host: "3.3.3.3", Port: "3333"})
-	kvs = append(kvs, &store.KVPair{Key: "path/3.3.3.3", Value: []byte("3.3.3.3:3333")})
+	kvs = append(kvs, &store.KVPair{Key: path.Join("path", discoveryPath, "3.3.3.3"), Value: []byte("3.3.3.3:3333")})
 	mockCh <- kvs
 	assert.Equal(t, <-ch, expected)
 
 	// Make sure that if an error occurs it retries.
 	// This third call to WatchTree will be checked later by AssertExpectations.
-	s.On("WatchTree", "path", mock.Anything).Return(mockCh, nil)
+	s.On("WatchTree", "path/"+discoveryPath, mock.Anything).Return(mockCh, nil)
 	close(mockCh)
 	// Give it enough time to call WatchTree.
 	time.Sleep(3)

docs/discovery.md

@@ -95,13 +95,13 @@ On each of your nodes, start the Swarm agent. The node IP address
 doesn't have to be public as long as the swarm manager can access it.
 
 ```bash
-swarm join --addr=<node_ip:2375> etcd://<etcd_ip>/<path>
+swarm join --addr=<node_ip:2375> etcd://<etcd_addr1>,<etcd_addr2>/<optional path prefix>
 ```
 
 Start the manager on any machine or your laptop.
 
 ```bash
-swarm manage -H tcp://<swarm_ip:swarm_port> etcd://<etcd_ip>/<path>
+swarm manage -H tcp://<swarm_ip:swarm_port> etcd://<etcd_addr1>,<etcd_addr2>/<optional path prefix>
 ```
 
 And then use the regular Docker commands.
@@ -117,7 +117,7 @@ docker -H tcp://<swarm_ip:swarm_port> logs ...
 You can list the nodes in your cluster.
 
 ```bash
-swarm list etcd://<etcd_ip>/<path>
+swarm list etcd://<etcd_addr1>,<etcd_addr2>/<optional path prefix>
 <node_ip:2375>
 ```
 
@@ -127,13 +127,13 @@ On each of your nodes, start the Swarm agent. The node IP address
 doesn't need to be public as long as the Swarm manager can access it.
 
 ```bash
-swarm join --addr=<node_ip:2375> consul://<consul_addr>/<path>
+swarm join --addr=<node_ip:2375> consul://<consul_addr>/<optional path prefix>
 ```
 
 Start the manager on any machine or your laptop.
 
 ```bash
-swarm manage -H tcp://<swarm_ip:swarm_port> consul://<consul_addr>/<path>
+swarm manage -H tcp://<swarm_ip:swarm_port> consul://<consul_addr>/<optional path prefix>
 ```
 
 And then use the regular Docker commands.
@@ -149,7 +149,7 @@ docker -H tcp://<swarm_ip:swarm_port> logs ...
 You can list the nodes in your cluster.
 
 ```bash
-swarm list consul://<consul_addr>/<path>
+swarm list consul://<consul_addr>/<optional path prefix>
 <node_ip:2375>
 ```
 
@@ -159,13 +159,13 @@ On each of your nodes, start the Swarm agent. The node IP doesn't have
 to be public as long as the swarm manager can access it.
 
 ```bash
-swarm join --addr=<node_ip:2375> zk://<zookeeper_addr1>,<zookeeper_addr2>/<path>
+swarm join --addr=<node_ip:2375> zk://<zookeeper_addr1>,<zookeeper_addr2>/<optional path prefix>
 ```
 
 Start the manager on any machine or your laptop.
 
 ```bash
-swarm manage -H tcp://<swarm_ip:swarm_port> zk://<zookeeper_addr1>,<zookeeper_addr2>/<path>
+swarm manage -H tcp://<swarm_ip:swarm_port> zk://<zookeeper_addr1>,<zookeeper_addr2>/<optional path prefix>
 ```
 
 You can then use the regular Docker commands.
@@ -181,7 +181,7 @@ docker -H tcp://<swarm_ip:swarm_port> logs ...
 You can list the nodes in the cluster.
 
 ```bash
-swarm list zk://<zookeeper_addr1>,<zookeeper_addr2>/<path>
+swarm list zk://<zookeeper_addr1>,<zookeeper_addr2>/<optional path prefix>
 <node_ip:2375>
 ```