Adds support for coordinates to client API.

api/api.go

@@ -44,6 +44,12 @@ type QueryOptions struct {
 	// Token is used to provide a per-request ACL token
 	// which overrides the agent's default token.
 	Token string
+
+	// Near is used to provide a node name that will sort the results
+	// in ascending order based on the estimated round trip time from
+	// that node. Setting this to "_agent" will use the agent's node
+	// for the sort.
+	Near string
 }
 
 // WriteOptions are used to parameterize a write
@@ -250,6 +256,9 @@ func (r *request) setQueryOptions(q *QueryOptions) {
 	if q.Token != "" {
 		r.params.Set("token", q.Token)
 	}
+	if q.Near != "" {
+		r.params.Set("near", q.Near)
+	}
 }
 
 // durToMsec converts a duration to a millisecond specified string

api/api_test.go

@@ -127,6 +127,7 @@ func TestSetQueryOptions(t *testing.T) {
 		WaitIndex:         1000,
 		WaitTime:          100 * time.Second,
 		Token:             "12345",
+		Near:              "nodex",
 	}
 	r.setQueryOptions(q)
 
@@ -148,6 +149,9 @@ func TestSetQueryOptions(t *testing.T) {
 	if r.params.Get("token") != "12345" {
 		t.Fatalf("bad: %v", r.params)
 	}
+	if r.params.Get("near") != "nodex" {
+		t.Fatalf("bad: %v", r.params)
+	}
 }
 
 func TestSetWriteOptions(t *testing.T) {

api/coordinate.go

@@ -0,0 +1,66 @@
+package api
+
+import (
+	"github.com/hashicorp/serf/coordinate"
+)
+
+// CoordinateEntry represents a node and its associated network coordinate.
+type CoordinateEntry struct {
+	Node  string
+	Coord *coordinate.Coordinate
+}
+
+// CoordinateDatacenterMap represents a datacenter and its associated WAN
+// nodes and their associates coordinates.
+type CoordinateDatacenterMap struct {
+	Datacenter  string
+	Coordinates []CoordinateEntry
+}
+
+// Coordinate can be used to query the coordinate endpoints
+type Coordinate struct {
+	c *Client
+}
+
+// Coordinate returns a handle to the coordinate endpoints
+func (c *Client) Coordinate() *Coordinate {
+	return &Coordinate{c}
+}
+
+// Datacenters is used to return the coordinates of all the servers in the WAN
+// pool.
+func (c *Coordinate) Datacenters() ([]*CoordinateDatacenterMap, error) {
+	r := c.c.newRequest("GET", "/v1/coordinate/datacenters")
+	_, resp, err := requireOK(c.c.doRequest(r))
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var out []*CoordinateDatacenterMap
+	if err := decodeBody(resp, &out); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Nodes is used to return the coordinates of all the nodes in the LAN pool.
+func (c *Coordinate) Nodes(q *QueryOptions) ([]*CoordinateEntry, *QueryMeta, error) {
+	r := c.c.newRequest("GET", "/v1/coordinate/nodes")
+	r.setQueryOptions(q)
+	rtt, resp, err := requireOK(c.c.doRequest(r))
+	if err != nil {
+		return nil, nil, err
+	}
+	defer resp.Body.Close()
+
+	qm := &QueryMeta{}
+	parseQueryMeta(resp, qm)
+	qm.RequestTime = rtt
+
+	var out []*CoordinateEntry
+	if err := decodeBody(resp, &out); err != nil {
+		return nil, nil, err
+	}
+	return out, qm, nil
+}

api/coordinate_test.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/consul/testutil"
+)
+
+func TestCoordinate_Datacenters(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	coordinate := c.Coordinate()
+
+	testutil.WaitForResult(func() (bool, error) {
+		datacenters, err := coordinate.Datacenters()
+		if err != nil {
+			return false, err
+		}
+
+		if len(datacenters) == 0 {
+			return false, fmt.Errorf("Bad: %v", datacenters)
+		}
+
+		return true, nil
+	}, func(err error) {
+		t.Fatalf("err: %s", err)
+	})
+}
+
+func TestCoordinate_Nodes(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	coordinate := c.Coordinate()
+
+	testutil.WaitForResult(func() (bool, error) {
+		_, _, err := coordinate.Nodes(nil)
+		if err != nil {
+			return false, err
+		}
+
+		// There's not a good way to populate coordinates without
+		// waiting for them to calculate and update, so the best
+		// we can do is call the endpoint and make sure we don't
+		// get an error.
+		return true, nil
+	}, func(err error) {
+		t.Fatalf("err: %s", err)
+	})
+}