Adding Status.Leader endpoint

consul/endpoints.md

@@ -0,0 +1,58 @@
+# Consul RPC Endpoints
+
+Consul provides a few high-level services, each of which exposes
+methods. The services exposed are:
+
+* Raft : Used to manipulate Raft from non-leader nodes
+* Status : Used to query status information
+* Catalog: Used to register, deregister, and query service information
+* Health: Used to notify of health checks and changes to health
+
+## Raft Service
+
+The Raft service is used to manipulate the Raft controls on the Leader
+node. It is only for internal use. It exposes the following methods:
+
+* Apply : Used to execute a command against the FSM
+* AddPeer: Used to add a peer to the group
+* RemovePeer: Used to remove a peer from the group
+
+## Status Service
+
+The status service is used to query for various status information
+from the Consul service. It exposes the following methods:
+
+* Ping : Used to test connectivity
+* Leader : Used to get the address of the leader
+
+## Catalog Service
+
+The catalog service is used to manage service discovery and registration.
+Nodes can register the services they provide, and deregister them later.
+The service exposes the following methods:
+
+* Register : Registers that a node provides a given service
+* Deregister : Deregisters that a node provides a given service
+
+* RemoveFailedNode: Used to force remove a failed node
+
+* ListDatacenters: List the known datacenters
+* ListServices : Lists the available services
+* ListNodes : Lists the available nodes
+* ServiceNodes: Returns the nodes that are part of a service
+* NodeServices: Returns the services that a node is registered for
+
+## Health Service
+
+The health service is used to manage health checking. Nodes have system
+health checks, as well as application health checks. This service is used to
+query health information, as well as for nodes to publish changes.
+
+* CheckPass : Used to inform that a check has passed
+* CheckWarn : Used to inform that a check is warning
+* CheckFail : Used to inform that a check has failed
+* RemoveCheck : Used to remove a health check
+
+* CheckInState : Gets the checks that in a given state
+* NodeChecks: Gets the checks a given node has
+

consul/status_endpoint.go

@@ -9,3 +9,14 @@ type Status struct {
 func (s *Status) Ping(args struct{}, reply *struct{}) error {
 	return nil
 }
+
+// Leader is used to get the address of the leader
+func (s *Status) Leader(args struct{}, reply *string) error {
+	leader := s.server.raft.Leader()
+	if leader != nil {
+		*reply = leader.String()
+	} else {
+		*reply = ""
+	}
+	return nil
+}

consul/status_endpoint_test.go

@@ -0,0 +1,49 @@
+package consul
+
+import (
+	"github.com/ugorji/go/codec"
+	"net"
+	"net/rpc"
+	"os"
+	"testing"
+	"time"
+)
+
+func rpcClient(t *testing.T, s *Server) *rpc.Client {
+	addr := s.config.RPCAddr
+	conn, err := net.DialTimeout("tcp", addr, time.Second)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	// Write the Consul RPC byte to set the mode
+	conn.Write([]byte{byte(rpcConsul)})
+
+	cc := codec.GoRpc.ClientCodec(conn, &codec.MsgpackHandle{})
+	return rpc.NewClientWithCodec(cc)
+}
+
+func TestStatusLeader(t *testing.T) {
+	dir1, s1 := testServer(t)
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	arg := struct{}{}
+	var leader string
+	if err := client.Call("Status.Leader", arg, &leader); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if leader != "" {
+		t.Fatalf("unexpected leader: %v", leader)
+	}
+
+	time.Sleep(500 * time.Millisecond)
+
+	if err := client.Call("Status.Leader", arg, &leader); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if leader == "" {
+		t.Fatalf("no leader")
+	}
+}