diff --git a/vendor/github.com/hashicorp/consul/lib/cluster.go b/vendor/github.com/hashicorp/consul/lib/cluster.go
new file mode 100644
index 0000000000..5df39251d8
--- /dev/null
+++ b/vendor/github.com/hashicorp/consul/lib/cluster.go
@@ -0,0 +1,36 @@
+package lib
+
+import (
+	"math/rand"
+	"time"
+)
+
+// DurationMinusBuffer returns a duration, minus a buffer and jitter
+// subtracted from the duration.  This function is used primarily for
+// servicing Consul TTL Checks in advance of the TTL.
+func DurationMinusBuffer(intv time.Duration, buffer time.Duration, jitter int64) time.Duration {
+	d := intv - buffer
+	d -= RandomStagger(time.Duration(int64(d) / jitter))
+	return d
+}
+
+// Returns a random stagger interval between 0 and the duration
+func RandomStagger(intv time.Duration) time.Duration {
+	return time.Duration(uint64(rand.Int63()) % uint64(intv))
+}
+
+// RateScaledInterval is used to choose an interval to perform an action in
+// order to target an aggregate number of actions per second across the whole
+// cluster.
+func RateScaledInterval(rate float64, min time.Duration, n int) time.Duration {
+	const minRate = 1 / 86400 // 1/(1 * time.Day)
+	if rate <= minRate {
+		return min
+	}
+	interval := time.Duration(float64(time.Second) * float64(n) / rate)
+	if interval < min {
+		return min
+	}
+
+	return interval
+}
diff --git a/vendor/github.com/hashicorp/consul/lib/math.go b/vendor/github.com/hashicorp/consul/lib/math.go
new file mode 100644
index 0000000000..1d0b6dc0f6
--- /dev/null
+++ b/vendor/github.com/hashicorp/consul/lib/math.go
@@ -0,0 +1,22 @@
+package lib
+
+func AbsInt(a int) int {
+	if a > 0 {
+		return a
+	}
+	return a * -1
+}
+
+func MaxInt(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func MinInt(a, b int) int {
+	if a > b {
+		return b
+	}
+	return a
+}
diff --git a/vendor/github.com/hashicorp/consul/lib/rand.go b/vendor/github.com/hashicorp/consul/lib/rand.go
new file mode 100644
index 0000000000..48307e63f3
--- /dev/null
+++ b/vendor/github.com/hashicorp/consul/lib/rand.go
@@ -0,0 +1,18 @@
+package lib
+
+import (
+	"math/rand"
+	"sync"
+	"time"
+)
+
+var (
+	once sync.Once
+)
+
+// SeedMathRand provides weak, but guaranteed seeding, which is better than
+// running with Go's default seed of 1.  A call to SeedMathRand() is expected
+// to be called via init(), but never a second time.
+func SeedMathRand() {
+	once.Do(func() { rand.Seed(time.Now().UTC().UnixNano()) })
+}
diff --git a/vendor/github.com/hashicorp/consul/lib/string.go b/vendor/github.com/hashicorp/consul/lib/string.go
new file mode 100644
index 0000000000..0780abb632
--- /dev/null
+++ b/vendor/github.com/hashicorp/consul/lib/string.go
@@ -0,0 +1,11 @@
+package lib
+
+// StrContains checks if a list contains a string
+func StrContains(l []string, s string) bool {
+	for _, v := range l {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}