Add regions endpoint

command/agent/http.go

@@ -109,6 +109,8 @@ func (s *HTTPServer) registerHandlers(enableDebug bool) {
 	s.mux.HandleFunc("/v1/agent/force-leave", s.wrap(s.AgentForceLeaveRequest))
 	s.mux.HandleFunc("/v1/agent/servers", s.wrap(s.AgentServersRequest))
 
+	s.mux.HandleFunc("/v1/regions", s.wrap(s.RegionListRequest))
+
 	s.mux.HandleFunc("/v1/status/leader", s.wrap(s.StatusLeaderRequest))
 	s.mux.HandleFunc("/v1/status/peers", s.wrap(s.StatusPeersRequest))
 

command/agent/region_endpoint.go

@@ -0,0 +1,24 @@
+package agent
+
+import (
+	"net/http"
+
+	"github.com/hashicorp/nomad/nomad/structs"
+)
+
+func (s *HTTPServer) RegionListRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	if req.Method != "GET" {
+		return nil, CodedError(405, ErrInvalidMethod)
+	}
+
+	var args structs.GenericRequest
+	if s.parse(resp, req, &args.Region, &args.QueryOptions) {
+		return nil, nil
+	}
+
+	var regions []string
+	if err := s.agent.RPC("Region.List", &args, &regions); err != nil {
+		return nil, err
+	}
+	return regions, nil
+}

command/agent/region_endpoint_test.go

@@ -0,0 +1,29 @@
+package agent
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHTTP_RegionList(t *testing.T) {
+	httpTest(t, nil, func(s *TestServer) {
+		// Make the HTTP request
+		req, err := http.NewRequest("GET", "/v1/regions", nil)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		respW := httptest.NewRecorder()
+
+		// Make the request
+		obj, err := s.Server.RegionListRequest(respW, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		out := obj.([]string)
+		if len(out) != 1 || out[0] != "global" {
+			t.Fatalf("unexpected regions: %#v", out)
+		}
+	})
+}

nomad/regions_endpoint.go

@@ -0,0 +1,16 @@
+package nomad
+
+import "github.com/hashicorp/nomad/nomad/structs"
+
+// Region is used to query and list the known regions
+type Region struct {
+	srv *Server
+}
+
+// List is used to list all of the known regions. No leader forwarding is
+// required for this endpoint because memberlist is used to populate the
+// peers list we read from.
+func (r *Region) List(args *structs.GenericRequest, reply *[]string) error {
+	*reply = r.srv.Regions()
+	return nil
+}

nomad/regions_endpoint_test.go

@@ -0,0 +1,46 @@
+package nomad
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/net-rpc-msgpackrpc"
+	"github.com/hashicorp/nomad/nomad/structs"
+	"github.com/hashicorp/nomad/testutil"
+)
+
+func TestRegionList(t *testing.T) {
+	// Make the servers
+	s1 := testServer(t, func(c *Config) {
+		c.Region = "region1"
+	})
+	defer s1.Shutdown()
+	codec := rpcClient(t, s1)
+
+	s2 := testServer(t, func(c *Config) {
+		c.Region = "region2"
+	})
+	defer s2.Shutdown()
+
+	// Join the servers
+	s2Addr := fmt.Sprintf("127.0.0.1:%d",
+		s2.config.SerfConfig.MemberlistConfig.BindPort)
+	if n, err := s1.Join([]string{s2Addr}); err != nil || n != 1 {
+		t.Fatalf("Failed joining: %v (%d joined)", err, n)
+	}
+
+	// Query the regions list
+	testutil.WaitForResult(func() (bool, error) {
+		var arg structs.GenericRequest
+		var out []string
+		if err := msgpackrpc.CallWithCodec(codec, "Region.List", &arg, &out); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		if len(out) != 2 || out[0] != "region1" || out[1] != "region2" {
+			t.Fatalf("unexpected regions: %v", out)
+		}
+		return true, nil
+	}, func(err error) {
+		t.Fatalf("err: %v", err)
+	})
+}

nomad/server.go

@@ -134,6 +134,7 @@ type endpoints struct {
 	Eval   *Eval
 	Plan   *Plan
 	Alloc  *Alloc
+	Region *Region
 }
 
 // NewServer is used to construct a new Nomad server from the
@@ -353,6 +354,7 @@ func (s *Server) setupRPC(tlsWrap tlsutil.DCWrapper) error {
 	s.endpoints.Eval = &Eval{s}
 	s.endpoints.Plan = &Plan{s}
 	s.endpoints.Alloc = &Alloc{s}
+	s.endpoints.Region = &Region{s}
 
 	// Register the handlers
 	s.rpcServer.Register(s.endpoints.Status)
@@ -361,6 +363,7 @@ func (s *Server) setupRPC(tlsWrap tlsutil.DCWrapper) error {
 	s.rpcServer.Register(s.endpoints.Eval)
 	s.rpcServer.Register(s.endpoints.Plan)
 	s.rpcServer.Register(s.endpoints.Alloc)
+	s.rpcServer.Register(s.endpoints.Region)
 
 	list, err := net.ListenTCP("tcp", s.config.RPCAddr)
 	if err != nil {
@@ -612,6 +615,18 @@ func (s *Server) State() *state.StateStore {
 	return s.fsm.State()
 }
 
+// Regions returns the known regions in the cluster.
+func (s *Server) Regions() []string {
+	s.peerLock.RLock()
+	defer s.peerLock.RUnlock()
+
+	regions := make([]string, 0, len(s.peers))
+	for region, _ := range s.peers {
+		regions = append(regions, region)
+	}
+	return regions
+}
+
 // inmemCodec is used to do an RPC call without going over a network
 type inmemCodec struct {
 	method string

nomad/server_test.go

@@ -7,6 +7,8 @@ import (
 	"sync/atomic"
 	"testing"
 	"time"
+
+	"github.com/hashicorp/nomad/testutil"
 )
 
 var nextPort uint32 = 15000
@@ -86,3 +88,34 @@ func TestServer_RPC(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 }
+
+func TestServer_Regions(t *testing.T) {
+	// Make the servers
+	s1 := testServer(t, func(c *Config) {
+		c.Region = "region1"
+	})
+	defer s1.Shutdown()
+
+	s2 := testServer(t, func(c *Config) {
+		c.Region = "region2"
+	})
+	defer s2.Shutdown()
+
+	// Join them together
+	s2Addr := fmt.Sprintf("127.0.0.1:%d",
+		s2.config.SerfConfig.MemberlistConfig.BindPort)
+	if n, err := s1.Join([]string{s2Addr}); err != nil || n != 1 {
+		t.Fatalf("Failed joining: %v (%d joined)", err, n)
+	}
+
+	// Try listing the regions
+	testutil.WaitForResult(func() (bool, error) {
+		out := s1.Regions()
+		if len(out) != 2 || out[0] != "region1" || out[1] != "region2" {
+			return false, fmt.Errorf("unexpected regions: %v", out)
+		}
+		return true, nil
+	}, func(err error) {
+		t.Fatalf("err: %v", err)
+	})
+}

website/source/docs/http/regions.html.md

@@ -0,0 +1,38 @@
+---
+layout: "http"
+page_title: "HTTP API: /v1/regions"
+sidebar_current: "docs-http-regions"
+description: >
+  The '/v1/regions' endpoint lists the known cluster regions.
+---
+
+# /v1/regions
+
+## GET
+
+<dl>
+  <dt>Description</dt>
+  <dd>
+    Returns the known region names.
+  </dd>
+
+  <dt>Method</dt>
+  <dd>GET</dd>
+
+  <dt>URL</dt>
+  <dd>`/v1/regions`</dd>
+
+  <dt>Parameters</dt>
+  <dd>
+    None
+  </dd>
+
+  <dt>Returns</dt>
+  <dd>
+
+    ```javascript
+    ["region1","region2"]
+    ```
+
+  </dd>
+</dl>

website/source/layouts/http.erb

@@ -89,6 +89,10 @@
 					</ul>
                 </li>
 
+                <li<%= sidebar_current("docs-http-regions") %>>
+                    <a href="/docs/http/regions.html">Regions</a>
+                </li>
+
 				<li<%= sidebar_current("docs-http-status") %>>
 					<a href="/docs/http/status.html">Status</a>
                 </li>