From 590ae08752bd7f604338c20fcc789ad635f4e546 Mon Sep 17 00:00:00 2001
From: Seth Hoenig <shoenig@duck.com>
Date: Tue, 7 Feb 2023 09:19:38 -0600
Subject: [PATCH] main: remove deprecated uses of rand.Seed (#16074)

* main: remove deprecated uses of rand.Seed

go1.20 deprecates rand.Seed, and seeds the rand package
automatically. Remove cases where we seed the random package,
and cleanup the one case where we intentionally create a
known random source.

* cl: update cl

* mod: update go mod
---
 .changelog/16074.txt                    | 3 +++
 client/servers/manager_internal_test.go | 5 -----
 command/agent/testagent.go              | 4 ----
 go.mod                                  | 2 +-
 main.go                                 | 9 ---------
 nomad/periodic_test.go                  | 1 -
 scheduler/spread_test.go                | 6 +++---
 7 files changed, 7 insertions(+), 23 deletions(-)
 create mode 100644 .changelog/16074.txt

diff --git a/.changelog/16074.txt b/.changelog/16074.txt
new file mode 100644
index 000000000..fb3bcfcff
--- /dev/null
+++ b/.changelog/16074.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+core: Eliminate deprecated practice of seeding rand package
+```
diff --git a/client/servers/manager_internal_test.go b/client/servers/manager_internal_test.go
index 17cf29b58..8c1765aa1 100644
--- a/client/servers/manager_internal_test.go
+++ b/client/servers/manager_internal_test.go
@@ -11,11 +11,6 @@ import (
 	"github.com/hashicorp/nomad/helper/testlog"
 )
 
-func init() {
-	// Seed the random number generator
-	rand.Seed(time.Now().UnixNano())
-}
-
 type fauxAddr struct {
 	Addr string
 }
diff --git a/command/agent/testagent.go b/command/agent/testagent.go
index 8cd38922f..52550b8af 100644
--- a/command/agent/testagent.go
+++ b/command/agent/testagent.go
@@ -27,10 +27,6 @@ import (
 	"github.com/hashicorp/nomad/testutil"
 )
 
-func init() {
-	rand.Seed(time.Now().UnixNano()) // seed random number generator
-}
-
 // TempDir defines the base dir for temporary directories.
 var TempDir = os.TempDir()
 
diff --git a/go.mod b/go.mod
index c8e62e614..16dbaf6b7 100644
--- a/go.mod
+++ b/go.mod
@@ -109,7 +109,6 @@ require (
 	github.com/rs/cors v1.8.3
 	github.com/ryanuber/columnize v2.1.2+incompatible
 	github.com/ryanuber/go-glob v1.0.0
-	github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529
 	github.com/shirou/gopsutil/v3 v3.22.12
 	github.com/shoenig/go-landlock v0.1.4
 	github.com/shoenig/test v0.6.1
@@ -252,6 +251,7 @@ require (
 	github.com/renier/xmlrpc v0.0.0-20170708154548-ce4a1a486c03 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/rogpeppe/go-internal v1.9.0 // indirect
+	github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529 // indirect
 	github.com/seccomp/libseccomp-golang v0.10.0 // indirect
 	github.com/shopspring/decimal v1.2.0 // indirect
 	github.com/sirupsen/logrus v1.9.0 // indirect
diff --git a/main.go b/main.go
index 1950b6a15..d244fe88b 100644
--- a/main.go
+++ b/main.go
@@ -22,7 +22,6 @@ import (
 	"github.com/hashicorp/nomad/command"
 	"github.com/hashicorp/nomad/version"
 	"github.com/mitchellh/cli"
-	"github.com/sean-/seed"
 )
 
 var (
@@ -74,19 +73,11 @@ var (
 	}
 )
 
-func init() {
-	seed.Init()
-}
-
 func main() {
 	os.Exit(Run(os.Args[1:]))
 }
 
 func Run(args []string) int {
-	return RunCustom(args)
-}
-
-func RunCustom(args []string) int {
 	// Create the meta object
 	metaPtr := new(command.Meta)
 	metaPtr.SetupUi(args)
diff --git a/nomad/periodic_test.go b/nomad/periodic_test.go
index 862a2c5e7..8db2e86d7 100644
--- a/nomad/periodic_test.go
+++ b/nomad/periodic_test.go
@@ -618,7 +618,6 @@ func TestPeriodicDispatch_Complex(t *testing.T) {
 }
 
 func shuffle(jobs []*structs.Job) {
-	rand.Seed(time.Now().Unix())
 	for i := range jobs {
 		j := rand.Intn(len(jobs))
 		jobs[i], jobs[j] = jobs[j], jobs[i]
diff --git a/scheduler/spread_test.go b/scheduler/spread_test.go
index ea581b9a1..87c4b8aee 100644
--- a/scheduler/spread_test.go
+++ b/scheduler/spread_test.go
@@ -691,13 +691,13 @@ func generateUnevenRacks(t *testing.T, nodes int, rackCount int) map[string]int
 
 	// print this so that any future test flakes can be more easily
 	// reproduced
-	seed := time.Now().UnixNano()
-	rand.Seed(seed)
+	seed := time.Now().Unix()
+	random := rand.NewSource(seed)
 	t.Logf("nodes=%d racks=%d seed=%d\n", nodes, rackCount, seed)
 
 	racks := map[string]int{}
 	for i := 0; i < nodes; i++ {
-		idx := rand.Intn(len(rackNames))
+		idx := int(random.Int63()) % len(rackNames)
 		racks[rackNames[idx]]++
 	}
 	return racks