Update Serf to include `serf.NumNodes()`

vendor/github.com/hashicorp/serf/coordinate/test_util.go

@@ -1,27 +0,0 @@
-package coordinate
-
-import (
-	"math"
-	"testing"
-)
-
-// verifyEqualFloats will compare f1 and f2 and fail if they are not
-// "equal" within a threshold.
-func verifyEqualFloats(t *testing.T, f1 float64, f2 float64) {
-	const zeroThreshold = 1.0e-6
-	if math.Abs(f1-f2) > zeroThreshold {
-		t.Fatalf("equal assertion fail, %9.6f != %9.6f", f1, f2)
-	}
-}
-
-// verifyEqualVectors will compare vec1 and vec2 and fail if they are not
-// "equal" within a threshold.
-func verifyEqualVectors(t *testing.T, vec1 []float64, vec2 []float64) {
-	if len(vec1) != len(vec2) {
-		t.Fatalf("vector length mismatch, %d != %d", len(vec1), len(vec2))
-	}
-
-	for i, _ := range vec1 {
-		verifyEqualFloats(t, vec1[i], vec2[i])
-	}
-}

vendor/github.com/hashicorp/serf/serf/serf.go

@@ -1680,3 +1680,13 @@ func (s *Serf) GetCachedCoordinate(name string) (coord *coordinate.Coordinate, o
 
 	return nil, false
 }
+
+// NumNodes returns the number of nodes in the serf cluster, regardless of
+// their health or status.
+func (s *Serf) NumNodes() (numNodes int) {
+	s.memberLock.RLock()
+	numNodes = len(s.members)
+	s.memberLock.RUnlock()
+
+	return numNodes
+}