Merge pull request #1666 from hashicorp/f-consul-lib

Refactor various utility functions into a consul/lib package

command/agent/agent.go

@@ -18,6 +18,7 @@ import (
 	"github.com/hashicorp/consul/consul"
 	"github.com/hashicorp/consul/consul/state"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/serf/coordinate"
 	"github.com/hashicorp/serf/serf"
 )
@@ -600,8 +601,8 @@ func (a *Agent) sendCoordinate() {
 	for {
 		rate := a.config.SyncCoordinateRateTarget
 		min := a.config.SyncCoordinateIntervalMin
-		intv := rateScaledInterval(rate, min, len(a.LANMembers()))
+		intv := lib.RateScaledInterval(rate, min, len(a.LANMembers()))
-		intv = intv + randomStagger(intv)
+		intv = intv + lib.RandomStagger(intv)
 
 		select {
 		case <-time.After(intv):

command/agent/check.go

@@ -15,6 +15,7 @@ import (
 	"github.com/armon/circbuf"
 	docker "github.com/fsouza/go-dockerclient"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/go-cleanhttp"
 )
 
@@ -131,7 +132,7 @@ func (c *CheckMonitor) Stop() {
 // run is invoked by a goroutine to run until Stop() is called
 func (c *CheckMonitor) run() {
 	// Get the randomized initial pause time
-	initialPauseTime := randomStagger(c.Interval)
+	initialPauseTime := lib.RandomStagger(c.Interval)
 	c.Logger.Printf("[DEBUG] agent: pausing %v before first invocation of %s", initialPauseTime, c.Script)
 	next := time.After(initialPauseTime)
 	for {
@@ -366,7 +367,7 @@ func (c *CheckHTTP) Stop() {
 // run is invoked by a goroutine to run until Stop() is called
 func (c *CheckHTTP) run() {
 	// Get the randomized initial pause time
-	initialPauseTime := randomStagger(c.Interval)
+	initialPauseTime := lib.RandomStagger(c.Interval)
 	c.Logger.Printf("[DEBUG] agent: pausing %v before first HTTP request of %s", initialPauseTime, c.HTTP)
 	next := time.After(initialPauseTime)
 	for {
@@ -482,7 +483,7 @@ func (c *CheckTCP) Stop() {
 // run is invoked by a goroutine to run until Stop() is called
 func (c *CheckTCP) run() {
 	// Get the randomized initial pause time
-	initialPauseTime := randomStagger(c.Interval)
+	initialPauseTime := lib.RandomStagger(c.Interval)
 	c.Logger.Printf("[DEBUG] agent: pausing %v before first socket connection of %s", initialPauseTime, c.TCP)
 	next := time.After(initialPauseTime)
 	for {
@@ -580,7 +581,7 @@ func (c *CheckDocker) Stop() {
 // run is invoked by a goroutine to run until Stop() is called
 func (c *CheckDocker) run() {
 	// Get the randomized initial pause time
-	initialPauseTime := randomStagger(c.Interval)
+	initialPauseTime := lib.RandomStagger(c.Interval)
 	c.Logger.Printf("[DEBUG] agent: pausing %v before first invocation of %s -c %s in container %s", initialPauseTime, c.Shell, c.Script, c.DockerContainerID)
 	next := time.After(initialPauseTime)
 	for {

command/agent/command.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/armon/go-metrics"
 	"github.com/armon/go-metrics/datadog"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/watch"
 	"github.com/hashicorp/go-checkpoint"
 	"github.com/hashicorp/go-reap"
@@ -424,7 +425,7 @@ func (c *Command) setupAgent(config *Config, logOutput io.Writer, logWriter *log
 
 		// Do an immediate check within the next 30 seconds
 		go func() {
-			time.Sleep(randomStagger(30 * time.Second))
+			time.Sleep(lib.RandomStagger(30 * time.Second))
 			c.checkpointResults(checkpoint.Check(updateParams))
 		}()
 	}

command/agent/config.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/watch"
 	"github.com/mitchellh/mapstructure"
 )
@@ -634,7 +635,7 @@ func DecodeConfig(r io.Reader) (*Config, error) {
 	allowedKeys := []string{"service", "services", "check", "checks"}
 	var unused []string
 	for _, field := range md.Unused {
-		if !strContains(allowedKeys, field) {
+		if !lib.StrContains(allowedKeys, field) {
 			unused = append(unused, field)
 		}
 	}

command/agent/config_test.go

@@ -11,6 +11,8 @@ import (
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/hashicorp/consul/lib"
 )
 
 func TestConfigEncryptBytes(t *testing.T) {
@@ -1103,7 +1105,7 @@ func TestDecodeConfig_Service(t *testing.T) {
 		t.Fatalf("bad: %v", serv)
 	}
 
-	if !strContains(serv.Tags, "master") {
+	if !lib.StrContains(serv.Tags, "master") {
 		t.Fatalf("bad: %v", serv)
 	}
 

command/agent/local.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/hashicorp/consul/consul"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 )
 
 const (
@@ -252,7 +253,7 @@ func (l *localState) UpdateCheck(checkID, status, output string) {
 	if l.config.CheckUpdateInterval > 0 && check.Status == status {
 		check.Output = output
 		if _, ok := l.deferCheck[checkID]; !ok {
-			intv := time.Duration(uint64(l.config.CheckUpdateInterval)/2) + randomStagger(l.config.CheckUpdateInterval)
+			intv := time.Duration(uint64(l.config.CheckUpdateInterval)/2) + lib.RandomStagger(l.config.CheckUpdateInterval)
 			deferSync := time.AfterFunc(intv, func() {
 				l.Lock()
 				if _, ok := l.checkStatus[checkID]; ok {
@@ -302,11 +303,11 @@ SYNC:
 		case <-l.consulCh:
 			// Stagger the retry on leader election, avoid a thundering heard
 			select {
-			case <-time.After(randomStagger(aeScale(syncStaggerIntv, len(l.iface.LANMembers())))):
+			case <-time.After(lib.RandomStagger(aeScale(syncStaggerIntv, len(l.iface.LANMembers())))):
 			case <-shutdownCh:
 				return
 			}
-		case <-time.After(syncRetryIntv + randomStagger(aeScale(syncRetryIntv, len(l.iface.LANMembers())))):
+		case <-time.After(syncRetryIntv + lib.RandomStagger(aeScale(syncRetryIntv, len(l.iface.LANMembers())))):
 		case <-shutdownCh:
 			return
 		}
@@ -317,7 +318,7 @@ SYNC:
 
 	// Schedule the next full sync, with a random stagger
 	aeIntv := aeScale(l.config.AEInterval, len(l.iface.LANMembers()))
-	aeIntv = aeIntv + randomStagger(aeIntv)
+	aeIntv = aeIntv + lib.RandomStagger(aeIntv)
 	aeTimer := time.After(aeIntv)
 
 	// Wait for sync events

command/agent/remote_exec_test.go

@@ -3,6 +3,7 @@ package agent
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"os"
 	"reflect"
 	"testing"
@@ -10,8 +11,17 @@ import (
 
 	"github.com/hashicorp/consul/consul/structs"
 	"github.com/hashicorp/consul/testutil"
+	"github.com/hashicorp/go-uuid"
 )
 
+func generateUUID() (ret string) {
+	var err error
+	if ret, err = uuid.GenerateUUID(); err != nil {
+		panic(fmt.Sprintf("Unable to generate a UUID, %v", err))
+	}
+	return ret
+}
+
 func TestRexecWriter(t *testing.T) {
 	writer := &rexecWriter{
 		BufCh:    make(chan []byte, 16),

command/agent/user_event.go

@@ -5,6 +5,7 @@ import (
 	"regexp"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/go-uuid"
 )
 
 const (
@@ -78,7 +79,10 @@ func (a *Agent) UserEvent(dc, token string, params *UserEvent) error {
 	}
 
 	// Format message
-	params.ID = generateUUID()
+	var err error
+	if params.ID, err = uuid.GenerateUUID(); err != nil {
+		return fmt.Errorf("UUID generation failed: %v", err)
+	}
 	params.Version = userEventMaxVersion
 	payload, err := encodeMsgPack(&params)
 	if err != nil {

command/agent/util.go

@@ -3,10 +3,8 @@ package agent
 import (
 	"bytes"
 	"crypto/md5"
-	crand "crypto/rand"
 	"fmt"
 	"math"
-	"math/rand"
 	"os"
 	"os/exec"
 	"os/user"
@@ -39,32 +37,6 @@ func aeScale(interval time.Duration, n int) time.Duration {
 	return time.Duration(multiplier) * interval
 }
 
-// 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 {
-	interval := time.Duration(float64(time.Second) * float64(n) / rate)
-	if interval < min {
-		return min
-	}
-
-	return interval
-}
-
-// 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))
-}
-
-// 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
-}
-
 // ExecScript returns a command to execute a script
 func ExecScript(script string) (*exec.Cmd, error) {
 	var shell, flag string
@@ -82,21 +54,6 @@ func ExecScript(script string) (*exec.Cmd, error) {
 	return cmd, nil
 }
 
-// generateUUID is used to generate a random UUID
-func generateUUID() string {
-	buf := make([]byte, 16)
-	if _, err := crand.Read(buf); err != nil {
-		panic(fmt.Errorf("failed to read random bytes: %v", err))
-	}
-
-	return fmt.Sprintf("%08x-%04x-%04x-%04x-%12x",
-		buf[0:4],
-		buf[4:6],
-		buf[6:8],
-		buf[8:10],
-		buf[10:16])
-}
-
 // decodeMsgPack is used to decode a MsgPack encoded object
 func decodeMsgPack(buf []byte, out interface{}) error {
 	return codec.NewDecoder(bytes.NewReader(buf), msgpackHandle).Decode(out)

command/agent/util_test.go

@@ -24,39 +24,6 @@ func TestAEScale(t *testing.T) {
 	}
 }
 
-func TestRateScaledInterval(t *testing.T) {
-	min := 1 * time.Second
-	rate := 200.0
-	if v := rateScaledInterval(rate, min, 0); v != min {
-		t.Fatalf("Bad: %v", v)
-	}
-	if v := rateScaledInterval(rate, min, 100); v != min {
-		t.Fatalf("Bad: %v", v)
-	}
-	if v := rateScaledInterval(rate, min, 200); v != 1*time.Second {
-		t.Fatalf("Bad: %v", v)
-	}
-	if v := rateScaledInterval(rate, min, 1000); v != 5*time.Second {
-		t.Fatalf("Bad: %v", v)
-	}
-	if v := rateScaledInterval(rate, min, 5000); v != 25*time.Second {
-		t.Fatalf("Bad: %v", v)
-	}
-	if v := rateScaledInterval(rate, min, 10000); v != 50*time.Second {
-		t.Fatalf("Bad: %v", v)
-	}
-}
-
-func TestRandomStagger(t *testing.T) {
-	intv := time.Minute
-	for i := 0; i < 10; i++ {
-		stagger := randomStagger(intv)
-		if stagger < 0 || stagger >= intv {
-			t.Fatalf("Bad: %v", stagger)
-		}
-	}
-}
-
 func TestStringHash(t *testing.T) {
 	in := "hello world"
 	expected := "5eb63bbbe01eeed093cb22bb8f5acdc3"

consul/acl_endpoint.go

@@ -7,6 +7,7 @@ import (
 	"github.com/armon/go-metrics"
 	"github.com/hashicorp/consul/acl"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/go-uuid"
 )
 
 // ACL endpoint is used to manipulate ACLs
@@ -62,7 +63,11 @@ func (a *ACL) Apply(args *structs.ACLRequest, reply *string) error {
 		if args.ACL.ID == "" {
 			state := a.srv.fsm.State()
 			for {
-				args.ACL.ID = generateUUID()
+				if args.ACL.ID, err = uuid.GenerateUUID(); err != nil {
+					a.srv.logger.Printf("[ERR] consul.acl: UUID generation failed: %v", err)
+					return err
+				}
+
 				_, acl, err := state.ACLGet(args.ACL.ID)
 				if err != nil {
 					a.srv.logger.Printf("[ERR] consul.acl: ACL lookup failed: %v", err)

consul/acl_endpoint_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/testutil"
 	"github.com/hashicorp/net-rpc-msgpackrpc"
 )
@@ -436,7 +437,7 @@ func TestACLEndpoint_List(t *testing.T) {
 		if s.ID == anonymousToken || s.ID == "root" {
 			continue
 		}
-		if !strContains(ids, s.ID) {
+		if !lib.StrContains(ids, s.ID) {
 			t.Fatalf("bad: %v", s)
 		}
 		if s.Name != "User token" {

consul/catalog_endpoint_test.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/testutil"
 	"github.com/hashicorp/net-rpc-msgpackrpc"
 )
@@ -978,7 +979,7 @@ func TestCatalogNodeServices(t *testing.T) {
 		t.Fatalf("bad: %v", out)
 	}
 	services := out.NodeServices.Services
-	if !strContains(services["db"].Tags, "primary") || services["db"].Port != 5000 {
+	if !lib.StrContains(services["db"].Tags, "primary") || services["db"].Port != 5000 {
 		t.Fatalf("bad: %v", out)
 	}
 	if len(services["web"].Tags) != 0 || services["web"].Port != 80 {

consul/fsm_test.go

@@ -2,12 +2,15 @@ package consul
 
 import (
 	"bytes"
+	"fmt"
 	"os"
 	"reflect"
 	"testing"
 
 	"github.com/hashicorp/consul/consul/state"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
+	"github.com/hashicorp/go-uuid"
 	"github.com/hashicorp/raft"
 )
 
@@ -38,6 +41,14 @@ func makeLog(buf []byte) *raft.Log {
 	}
 }
 
+func generateUUID() (ret string) {
+	var err error
+	if ret, err = uuid.GenerateUUID(); err != nil {
+		panic(fmt.Sprintf("Unable to generate a UUID, %v", err))
+	}
+	return ret
+}
+
 func TestFSM_RegisterNode(t *testing.T) {
 	fsm, err := NewFSM(nil, os.Stderr)
 	if err != nil {
@@ -452,7 +463,7 @@ func TestFSM_SnapshotRestore(t *testing.T) {
 	if len(fooSrv.Services) != 2 {
 		t.Fatalf("Bad: %v", fooSrv)
 	}
-	if !strContains(fooSrv.Services["db"].Tags, "primary") {
+	if !lib.StrContains(fooSrv.Services["db"].Tags, "primary") {
 		t.Fatalf("Bad: %v", fooSrv)
 	}
 	if fooSrv.Services["db"].Port != 5000 {

consul/health_endpoint_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/testutil"
 	"github.com/hashicorp/net-rpc-msgpackrpc"
 )
@@ -377,10 +378,10 @@ func TestHealth_ServiceNodes(t *testing.T) {
 	if nodes[1].Node.Node != "foo" {
 		t.Fatalf("Bad: %v", nodes[1])
 	}
-	if !strContains(nodes[0].Service.Tags, "slave") {
+	if !lib.StrContains(nodes[0].Service.Tags, "slave") {
 		t.Fatalf("Bad: %v", nodes[0])
 	}
-	if !strContains(nodes[1].Service.Tags, "master") {
+	if !lib.StrContains(nodes[1].Service.Tags, "master") {
 		t.Fatalf("Bad: %v", nodes[1])
 	}
 	if nodes[0].Checks[0].Status != structs.HealthWarning {

consul/internal_endpoint_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/testutil"
 	"github.com/hashicorp/net-rpc-msgpackrpc"
 )
@@ -56,7 +57,7 @@ func TestInternal_NodeInfo(t *testing.T) {
 	if nodes[0].Node != "foo" {
 		t.Fatalf("Bad: %v", nodes[0])
 	}
-	if !strContains(nodes[0].Services[0].Tags, "master") {
+	if !lib.StrContains(nodes[0].Services[0].Tags, "master") {
 		t.Fatalf("Bad: %v", nodes[0])
 	}
 	if nodes[0].Checks[0].Status != structs.HealthPassing {
@@ -130,7 +131,7 @@ func TestInternal_NodeDump(t *testing.T) {
 		switch node.Node {
 		case "foo":
 			foundFoo = true
-			if !strContains(node.Services[0].Tags, "master") {
+			if !lib.StrContains(node.Services[0].Tags, "master") {
 				t.Fatalf("Bad: %v", nodes[0])
 			}
 			if node.Checks[0].Status != structs.HealthPassing {
@@ -139,7 +140,7 @@ func TestInternal_NodeDump(t *testing.T) {
 
 		case "bar":
 			foundBar = true
-			if !strContains(node.Services[0].Tags, "slave") {
+			if !lib.StrContains(node.Services[0].Tags, "slave") {
 				t.Fatalf("Bad: %v", nodes[1])
 			}
 			if node.Checks[0].Status != structs.HealthWarning {

consul/prepared_query_endpoint.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/armon/go-metrics"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/go-uuid"
 )
 
 var (
@@ -41,7 +42,9 @@ func (p *PreparedQuery) Apply(args *structs.PreparedQueryRequest, reply *string)
 		// to collide since this isn't inside a write transaction.
 		state := p.srv.fsm.State()
 		for {
-			args.Query.ID = generateUUID()
+			if args.Query.ID, err = uuid.GenerateUUID(); err != nil {
+				return fmt.Errorf("UUID generation for prepared query failed: %v", err)
+			}
 			_, query, err := state.PreparedQueryGet(args.Query.ID)
 			if err != nil {
 				return fmt.Errorf("Prepared query lookup failed: %v", err)

consul/rpc.go

@@ -12,6 +12,7 @@ import (
 	"github.com/armon/go-metrics"
 	"github.com/hashicorp/consul/consul/state"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/memberlist"
 	"github.com/hashicorp/net-rpc-msgpackrpc"
 	"github.com/hashicorp/yamux"
@@ -329,7 +330,7 @@ func (s *Server) blockingRPC(queryOpts *structs.QueryOptions, queryMeta *structs
 	}
 
 	// Apply a small amount of jitter to the request.
-	queryOpts.MaxQueryTime += randomStagger(queryOpts.MaxQueryTime / jitterFraction)
+	queryOpts.MaxQueryTime += lib.RandomStagger(queryOpts.MaxQueryTime / jitterFraction)
 
 	// Setup a query timeout.
 	timeout = time.NewTimer(queryOpts.MaxQueryTime)

consul/session_endpoint.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/armon/go-metrics"
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/go-uuid"
 )
 
 // Session endpoint is used to manipulate sessions for KV
@@ -61,7 +62,11 @@ func (s *Session) Apply(args *structs.SessionRequest, reply *string) error {
 		// Generate a new session ID, verify uniqueness
 		state := s.srv.fsm.State()
 		for {
-			args.Session.ID = generateUUID()
+			var err error
+			if args.Session.ID, err = uuid.GenerateUUID(); err != nil {
+				s.srv.logger.Printf("[ERR] consul.session: UUID generation failed: %v", err)
+				return err
+			}
 			_, sess, err := state.SessionGet(args.Session.ID)
 			if err != nil {
 				s.srv.logger.Printf("[ERR] consul.session: Session lookup failed: %v", err)

consul/session_endpoint_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/testutil"
 	"github.com/hashicorp/net-rpc-msgpackrpc"
 )
@@ -217,7 +218,7 @@ func TestSessionEndpoint_List(t *testing.T) {
 	}
 	for i := 0; i < len(sessions.Sessions); i++ {
 		s := sessions.Sessions[i]
-		if !strContains(ids, s.ID) {
+		if !lib.StrContains(ids, s.ID) {
 			t.Fatalf("bad: %v", s)
 		}
 		if s.Node != "foo" {
@@ -318,7 +319,7 @@ func TestSessionEndpoint_Renew(t *testing.T) {
 	}
 	for i := 0; i < len(sessions.Sessions); i++ {
 		s := sessions.Sessions[i]
-		if !strContains(ids, s.ID) {
+		if !lib.StrContains(ids, s.ID) {
 			t.Fatalf("bad: %v", s)
 		}
 		if s.Node != "foo" {
@@ -352,7 +353,7 @@ func TestSessionEndpoint_Renew(t *testing.T) {
 		}
 
 		s := session.Sessions[0]
-		if !strContains(ids, s.ID) {
+		if !lib.StrContains(ids, s.ID) {
 			t.Fatalf("bad: %v", s)
 		}
 		if s.Node != "foo" {
@@ -379,7 +380,7 @@ func TestSessionEndpoint_Renew(t *testing.T) {
 
 	for i := 0; i < len(sessionsL1.Sessions); i++ {
 		s := sessionsL1.Sessions[i]
-		if !strContains(ids, s.ID) {
+		if !lib.StrContains(ids, s.ID) {
 			t.Fatalf("bad: %v", s)
 		}
 		if s.Node != "foo" {
@@ -411,7 +412,7 @@ func TestSessionEndpoint_Renew(t *testing.T) {
 	if len(sessionsL2.Sessions) != 0 {
 		for i := 0; i < len(sessionsL2.Sessions); i++ {
 			s := sessionsL2.Sessions[i]
-			if !strContains(ids, s.ID) {
+			if !lib.StrContains(ids, s.ID) {
 				t.Fatalf("bad: %v", s)
 			}
 			if s.Node != "foo" {
@@ -476,7 +477,7 @@ func TestSessionEndpoint_NodeSessions(t *testing.T) {
 	}
 	for i := 0; i < len(sessions.Sessions); i++ {
 		s := sessions.Sessions[i]
-		if !strContains(ids, s.ID) {
+		if !lib.StrContains(ids, s.ID) {
 			t.Fatalf("bad: %v", s)
 		}
 		if s.Node != "foo" {

consul/state/state_store_test.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/serf/coordinate"
 )
 
@@ -1189,16 +1190,6 @@ func TestStateStore_Services(t *testing.T) {
 	}
 }
 
-// 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
-}
-
 func TestStateStore_ServiceNodes(t *testing.T) {
 	s := testStateStore(t)
 
@@ -1249,7 +1240,7 @@ func TestStateStore_ServiceNodes(t *testing.T) {
 	if nodes[0].ServiceID != "db" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if !strContains(nodes[0].ServiceTags, "slave") {
+	if !lib.StrContains(nodes[0].ServiceTags, "slave") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[0].ServicePort != 8000 {
@@ -1265,7 +1256,7 @@ func TestStateStore_ServiceNodes(t *testing.T) {
 	if nodes[1].ServiceID != "db2" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if !strContains(nodes[1].ServiceTags, "slave") {
+	if !lib.StrContains(nodes[1].ServiceTags, "slave") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[1].ServicePort != 8001 {
@@ -1281,7 +1272,7 @@ func TestStateStore_ServiceNodes(t *testing.T) {
 	if nodes[2].ServiceID != "db" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if !strContains(nodes[2].ServiceTags, "master") {
+	if !lib.StrContains(nodes[2].ServiceTags, "master") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[2].ServicePort != 8000 {
@@ -1328,7 +1319,7 @@ func TestStateStore_ServiceTagNodes(t *testing.T) {
 	if nodes[0].Address != "127.0.0.1" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if !strContains(nodes[0].ServiceTags, "master") {
+	if !lib.StrContains(nodes[0].ServiceTags, "master") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[0].ServicePort != 8000 {
@@ -1375,7 +1366,7 @@ func TestStateStore_ServiceTagNodes_MultipleTags(t *testing.T) {
 	if nodes[0].Address != "127.0.0.1" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if !strContains(nodes[0].ServiceTags, "master") {
+	if !lib.StrContains(nodes[0].ServiceTags, "master") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[0].ServicePort != 8000 {
@@ -1409,7 +1400,7 @@ func TestStateStore_ServiceTagNodes_MultipleTags(t *testing.T) {
 	if nodes[0].Address != "127.0.0.1" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if !strContains(nodes[0].ServiceTags, "dev") {
+	if !lib.StrContains(nodes[0].ServiceTags, "dev") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[0].ServicePort != 8001 {

consul/util.go

@@ -1,17 +1,13 @@
 package consul
 
 import (
-	crand "crypto/rand"
 	"encoding/binary"
 	"fmt"
-	"math/rand"
 	"net"
 	"os"
 	"path/filepath"
 	"runtime"
 	"strconv"
-	"strings"
-	"time"
 
 	"github.com/hashicorp/serf/serf"
 )
@@ -83,24 +79,6 @@ func init() {
 	privateBlocks[5] = block
 }
 
-// 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
-}
-
-func ToLowerList(l []string) []string {
-	var out []string
-	for _, value := range l {
-		out = append(out, strings.ToLower(value))
-	}
-	return out
-}
-
 // ensurePath is used to make sure a path exists
 func ensurePath(path string, dir bool) error {
 	if !dir {
@@ -309,23 +287,3 @@ func runtimeStats() map[string]string {
 		"cpu_count":  strconv.FormatInt(int64(runtime.NumCPU()), 10),
 	}
 }
-
-// generateUUID is used to generate a random UUID
-func generateUUID() string {
-	buf := make([]byte, 16)
-	if _, err := crand.Read(buf); err != nil {
-		panic(fmt.Errorf("failed to read random bytes: %v", err))
-	}
-
-	return fmt.Sprintf("%08x-%04x-%04x-%04x-%12x",
-		buf[0:4],
-		buf[4:6],
-		buf[6:8],
-		buf[8:10],
-		buf[10:16])
-}
-
-// 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))
-}

consul/util_test.go

@@ -6,30 +6,10 @@ import (
 	"net"
 	"regexp"
 	"testing"
-	"time"
 
 	"github.com/hashicorp/serf/serf"
 )
 
-func TestStrContains(t *testing.T) {
-	l := []string{"a", "b", "c"}
-	if !strContains(l, "b") {
-		t.Fatalf("should contain")
-	}
-	if strContains(l, "d") {
-		t.Fatalf("should not contain")
-	}
-}
-
-func TestToLowerList(t *testing.T) {
-	l := []string{"ABC", "Abc", "abc"}
-	for _, value := range ToLowerList(l) {
-		if value != "abc" {
-			t.Fatalf("failed lowercasing")
-		}
-	}
-}
-
 func TestGetPrivateIP(t *testing.T) {
 	ip, _, err := net.ParseCIDR("10.1.2.3/32")
 	if err != nil {
@@ -295,13 +275,3 @@ func TestGenerateUUID(t *testing.T) {
 		}
 	}
 }
-
-func TestRandomStagger(t *testing.T) {
-	intv := time.Minute
-	for i := 0; i < 10; i++ {
-		stagger := randomStagger(intv)
-		if stagger < 0 || stagger >= intv {
-			t.Fatalf("Bad: %v", stagger)
-		}
-	}
-}

lib/cluster.go

@@ -0,0 +1,23 @@
+package lib
+
+import (
+	"math/rand"
+	"time"
+)
+
+// 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 {
+	interval := time.Duration(float64(time.Second) * float64(n) / rate)
+	if interval < min {
+		return min
+	}
+
+	return interval
+}

lib/cluster_test.go

@@ -0,0 +1,39 @@
+package lib
+
+import (
+	"testing"
+	"time"
+)
+
+func TestRandomStagger(t *testing.T) {
+	intv := time.Minute
+	for i := 0; i < 10; i++ {
+		stagger := RandomStagger(intv)
+		if stagger < 0 || stagger >= intv {
+			t.Fatalf("Bad: %v", stagger)
+		}
+	}
+}
+
+func TestRateScaledInterval(t *testing.T) {
+	min := 1 * time.Second
+	rate := 200.0
+	if v := RateScaledInterval(rate, min, 0); v != min {
+		t.Fatalf("Bad: %v", v)
+	}
+	if v := RateScaledInterval(rate, min, 100); v != min {
+		t.Fatalf("Bad: %v", v)
+	}
+	if v := RateScaledInterval(rate, min, 200); v != 1*time.Second {
+		t.Fatalf("Bad: %v", v)
+	}
+	if v := RateScaledInterval(rate, min, 1000); v != 5*time.Second {
+		t.Fatalf("Bad: %v", v)
+	}
+	if v := RateScaledInterval(rate, min, 5000); v != 25*time.Second {
+		t.Fatalf("Bad: %v", v)
+	}
+	if v := RateScaledInterval(rate, min, 10000); v != 50*time.Second {
+		t.Fatalf("Bad: %v", v)
+	}
+}

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()) })
+}

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
+}

lib/string_test.go

@@ -0,0 +1,15 @@
+package lib
+
+import (
+	"testing"
+)
+
+func TestStrContains(t *testing.T) {
+	l := []string{"a", "b", "c"}
+	if !StrContains(l, "b") {
+		t.Fatalf("should contain")
+	}
+	if StrContains(l, "d") {
+		t.Fatalf("should not contain")
+	}
+}

main.go

@@ -6,8 +6,14 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+
+	"github.com/hashicorp/consul/lib"
 )
 
+func init() {
+	lib.SeedMathRand()
+}
+
 func main() {
 	os.Exit(realMain())
 }

scripts/verify_no_uuid.sh

@@ -1,12 +1,12 @@
 #!/bin/bash
 
-grep generateUUID consul/state/state_store.go
+grep GenerateUUID consul/state/state_store.go
 RESULT=$?
 if [ $RESULT -eq 0 ]; then
     exit 1
 fi
 
-grep generateUUID consul/fsm.go
+grep GenerateUUID consul/fsm.go
 RESULT=$?
 if [ $RESULT -eq 0 ]; then
     exit 1

scripts/windows/verify_no_uuid.bat

@@ -5,10 +5,10 @@ setlocal
 if not exist %1\consul\state\state_store.go exit /B 1
 if not exist %1\consul\fsm.go exit /B 1
 
-findstr /R generateUUID %1\consul\state\state_store.go 1>nul
+findstr /R GenerateUUID %1\consul\state\state_store.go 1>nul
 if not %ERRORLEVEL% EQU 1 exit /B 1
 
-findstr generateUUID %1\consul\fsm.go 1>nul
+findstr GenerateUUID %1\consul\fsm.go 1>nul
 if not %ERRORLEVEL% EQU 1 exit /B 1
 
 exit /B 0