Merge pull request #232 from vieux/ip_discovery

Proposal: add a `list` discovery service to give a list of ips

discovery/README.md

@@ -128,6 +128,22 @@ $ swarm list --discovery zk://<zookeeper_addr1>,<zookeeper_addr2>/<path>
 <node_ip:2375>
 ```
 
+###### Using a static list of ips
+
+```bash
+# start the manager on any machine or your laptop
+$ swarm manage --discovery <node_ip1:2375>,<node_ip2:2375> -H=<swarm_ip:swarm_port>
+#or
+$ swarm manage --discovery nodes://<node_ip1:2375>,<node_ip2:2375> -H=<swarm_ip:swarm_port>
+
+# use the regular docker cli
+$ docker -H <swarm_ip:swarm_port> info
+$ docker -H <swarm_ip:swarm_port> run ...
+$ docker -H <swarm_ip:swarm_port> ps
+$ docker -H <swarm_ip:swarm_port> logs ...
+...
+```
+
 ## Contributing
 
 Contributing a new discovery backend is easy,

discovery/discovery.go

@@ -55,6 +55,11 @@ func New(rawurl string, heartbeat int) (DiscoveryService, error) {
 		return nil, err
 	}
 
+	// nodes:port,node2:port => nodes://node1:port,node2:port
+	if url.Scheme == "" {
+		url.Scheme = "nodes"
+	}
+
 	if discovery, exists := discoveries[url.Scheme]; exists {
 		log.Debugf("Initializing %q discovery service with %q", url.Scheme, url.Host+url.Path)
 		err := discovery.Initialize(url.Host+url.Path, heartbeat)

discovery/nodes/nodes.go

@@ -0,0 +1,33 @@
+package nodes
+
+import (
+	"strings"
+
+	"github.com/docker/swarm/discovery"
+)
+
+type NodesDiscoveryService struct {
+	nodes []*discovery.Node
+}
+
+func init() {
+	discovery.Register("nodes", &NodesDiscoveryService{})
+}
+
+func (s *NodesDiscoveryService) Initialize(uris string, _ int) error {
+	for _, ip := range strings.Split(uris, ",") {
+		s.nodes = append(s.nodes, discovery.NewNode(ip))
+	}
+
+	return nil
+}
+func (s *NodesDiscoveryService) Fetch() ([]*discovery.Node, error) {
+	return s.nodes, nil
+}
+
+func (s *NodesDiscoveryService) Watch(callback discovery.WatchCallback) {
+}
+
+func (s *NodesDiscoveryService) Register(addr string) error {
+	return discovery.ErrNotImplemented
+}

discovery/nodes/nodes_test.go

@@ -0,0 +1,20 @@
+package nodes
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestInitialise(t *testing.T) {
+	discovery := &NodesDiscoveryService{}
+	discovery.Initialize("1.1.1.1:1111,2.2.2.2:2222", 0)
+	assert.Equal(t, len(discovery.nodes), 2)
+	assert.Equal(t, discovery.nodes[0].String(), "1.1.1.1:1111")
+	assert.Equal(t, discovery.nodes[1].String(), "2.2.2.2:2222")
+}
+
+func TestRegister(t *testing.T) {
+	discovery := &NodesDiscoveryService{}
+	assert.Error(t, discovery.Register("0.0.0.0"))
+}

flags.go

@@ -6,7 +6,7 @@ var (
 	flDiscovery = cli.StringFlag{
 		Name:   "discovery",
 		Value:  "",
-		Usage:  "DiscoveryService to use [token://<token>, etcd://<ip1>,<ip2>/<path>, file://path/to/file, consul://<addr>/<path>, zk://<ip1>,<ip2>/<path>]",
+		Usage:  "DiscoveryService to use [token://<token>,\n\t\t\t\t etcd://<ip1>,<ip2>/<path>,\n\t\t\t\t file://path/to/file,\n\t\t\t\t consul://<addr>/<path>,\n\t\t\t\t zk://<ip1>,<ip2>/<path>,\n\t\t\t\t <ip1>,<ip2>]",
 		EnvVar: "SWARM_DISCOVERY",
 	}
 	flAddr = cli.StringFlag{

main.go

@@ -11,6 +11,7 @@ import (
 	_ "github.com/docker/swarm/discovery/consul"
 	_ "github.com/docker/swarm/discovery/etcd"
 	_ "github.com/docker/swarm/discovery/file"
+	_ "github.com/docker/swarm/discovery/nodes"
 	"github.com/docker/swarm/discovery/token"
 	_ "github.com/docker/swarm/discovery/zookeeper"
 )

manage.go

@@ -74,29 +74,9 @@ func manage(c *cli.Context) {
 	cluster := cluster.NewCluster(tlsConfig)
 	cluster.Events(&logHandler{})
 
-	go func() {
-		if c.String("discovery") != "" {
-			d, err := discovery.New(c.String("discovery"), c.Int("heartbeat"))
-			if err != nil {
-				log.Fatal(err)
-			}
-
-			nodes, err := d.Fetch()
-			if err != nil {
-				log.Fatal(err)
-
-			}
-			cluster.UpdateNodes(nodes)
-
-			go d.Watch(cluster.UpdateNodes)
-		} else {
-			var nodes []*discovery.Node
-			for _, arg := range c.Args() {
-				nodes = append(nodes, discovery.NewNode(arg))
-			}
-			cluster.UpdateNodes(nodes)
-		}
-	}()
+	if !c.IsSet("discovery") {
+		log.Fatal("--discovery required to manage a cluster")
+	}
 
 	s, err := strategy.New(c.String("strategy"))
 	if err != nil {
@@ -112,6 +92,24 @@ func manage(c *cli.Context) {
 	if err != nil {
 		log.Fatal(err)
 	}
+
+	// get the list of nodes from the discovery service
+	go func() {
+		d, err := discovery.New(c.String("discovery"), c.Int("heartbeat"))
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		nodes, err := d.Fetch()
+		if err != nil {
+			log.Fatal(err)
+
+		}
+		cluster.UpdateNodes(nodes)
+
+		go d.Watch(cluster.UpdateNodes)
+	}()
+
 	sched := scheduler.NewScheduler(
 		cluster,
 		s,