[management] remove old math rand lib (#6836)

management/internals/modules/agentnetwork/labelgen/labelgen.go

@@ -3,9 +3,10 @@ package labelgen
 
 import (
 	"fmt"
-	"math/rand"
 	"sort"
 	"sync"
+
+	"github.com/netbirdio/netbird/management/server/util"
 )
 
 // pickAttempts caps the random retries before falling back to the
@@ -40,16 +41,15 @@ func uniqueWords() []string {
 // PickUnique selects a label not already in `taken`. It tries up to
 // pickAttempts random picks; on exhaustion it scans the deduplicated
 // wordlist for any remaining free entry, and if none is left appends
-// `-<fallbackSuffix>` to a deterministic word and returns. The caller
-// is responsible for seeding rng (math/rand).
-func PickUnique(rng *rand.Rand, taken map[string]struct{}, fallbackSuffix string) string {
+// `-<fallbackSuffix>` to a random word and returns.
+func PickUnique(taken map[string]struct{}, fallbackSuffix string) string {
 	pool := uniqueWords()
 	if len(pool) == 0 {
 		return fallbackSuffix
 	}
 
 	for i := 0; i < pickAttempts; i++ {
-		w := pool[rng.Intn(len(pool))]
+		w := pool[util.RandIntn(len(pool))]
 		if _, ok := taken[w]; !ok {
 			return w
 		}
@@ -61,7 +61,7 @@ func PickUnique(rng *rand.Rand, taken map[string]struct{}, fallbackSuffix string
 		}
 	}
 
-	w := pool[rng.Intn(len(pool))]
+	w := pool[util.RandIntn(len(pool))]
 	return fmt.Sprintf("%s-%s", w, fallbackSuffix)
 }
 
@@ -74,10 +74,10 @@ func PickUnique(rng *rand.Rand, taken map[string]struct{}, fallbackSuffix string
 // a noun spans len(adjectives) * 857 instead. Uniqueness is enforced by a
 // database constraint and retried by the caller, rather than guessed from a
 // pre-read set that a concurrent allocation can invalidate.
-func PickTuple(rng *rand.Rand) string {
+func PickTuple() string {
 	nouns := uniqueWords()
 	if len(nouns) == 0 || len(adjectives) == 0 {
 		return ""
 	}
-	return adjectives[rng.Intn(len(adjectives))] + "-" + nouns[rng.Intn(len(nouns))]
+	return adjectives[util.RandIntn(len(adjectives))] + "-" + nouns[util.RandIntn(len(nouns))]
 }

management/internals/modules/agentnetwork/labelgen/labelgen_test.go

@@ -1,7 +1,7 @@
 package labelgen
 
 import (
-	"math/rand"
+	"slices"
 	"strings"
 	"testing"
 
@@ -9,19 +9,12 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// TestPickUnique_DeterministicWithSeededRng locks the property the
-// caller relies on: same seed + same taken set → same pick. Without
-// that, the bootstrap flow can't reproduce a label across retries.
-func TestPickUnique_DeterministicWithSeededRng(t *testing.T) {
-	taken := map[string]struct{}{}
+// TestPickUnique_ReturnsWordFromPool confirms a pick against an empty
+// taken set is always drawn verbatim from the wordlist.
+func TestPickUnique_ReturnsWordFromPool(t *testing.T) {
+	got := PickUnique(map[string]struct{}{}, "abcd")
 
-	rngA := rand.New(rand.NewSource(42))
-	rngB := rand.New(rand.NewSource(42))
-
-	a := PickUnique(rngA, taken, "abcd")
-	b := PickUnique(rngB, taken, "abcd")
-
-	assert.Equal(t, a, b, "Same seed and taken set must produce identical pick")
+	assert.True(t, slices.Contains(uniqueWords(), got), "Pick %q must be drawn from the wordlist", got)
 }
 
 // TestPickUnique_AvoidsTakenWordsWhenMostAreReserved seeds taken with
@@ -46,8 +39,7 @@ func TestPickUnique_AvoidsTakenWordsWhenMostAreReserved(t *testing.T) {
 		taken[w] = struct{}{}
 	}
 
-	rng := rand.New(rand.NewSource(7))
-	got := PickUnique(rng, taken, "abcd")
+	got := PickUnique(taken, "abcd")
 
 	_, isFree := free[got]
 	assert.True(t, isFree, "PickUnique must return one of the free words; got %q", got)
@@ -65,8 +57,7 @@ func TestPickUnique_FallsBackWhenAllReserved(t *testing.T) {
 		taken[w] = struct{}{}
 	}
 
-	rng := rand.New(rand.NewSource(99))
-	got := PickUnique(rng, taken, "abcd")
+	got := PickUnique(taken, "abcd")
 
 	assert.True(t, strings.HasSuffix(got, "-abcd"), "Exhausted pool must produce <word>-<suffix>; got %q", got)
 
@@ -114,9 +105,8 @@ func TestPickTuple_ShapeAndPoolMembership(t *testing.T) {
 		inAdjectives[a] = struct{}{}
 	}
 
-	rng := rand.New(rand.NewSource(7))
 	for i := 0; i < 200; i++ {
-		got := PickTuple(rng)
+		got := PickTuple()
 
 		parts := strings.Split(got, "-")
 		require.Len(t, parts, 2, "PickTuple must produce exactly two hyphen-joined words; got %q", got)
@@ -158,22 +148,13 @@ func TestAdjectives_AreDNSSafeAndDeduplicated(t *testing.T) {
 	assert.Greater(t, len(adjectives), 150, "Adjective pool too small to give a useful namespace")
 }
 
-// TestPickTuple_DeterministicWithSeededRng documents that generation is a pure
-// function of the rng, which is what makes allocation retries reproducible in tests.
-func TestPickTuple_DeterministicWithSeededRng(t *testing.T) {
-	a := PickTuple(rand.New(rand.NewSource(42)))
-	b := PickTuple(rand.New(rand.NewSource(42)))
-	assert.Equal(t, a, b, "Same seed must yield the same tuple")
-}
-
 // TestPickTuple_SpansALargeNamespace guards the reason we moved to tuples: a
 // single-word pool caps the GLOBAL namespace at 857. Drawing many tuples must
 // yield overwhelmingly distinct values.
 func TestPickTuple_SpansALargeNamespace(t *testing.T) {
-	rng := rand.New(rand.NewSource(11))
 	seen := make(map[string]struct{}, 2000)
 	for i := 0; i < 2000; i++ {
-		seen[PickTuple(rng)] = struct{}{}
+		seen[PickTuple()] = struct{}{}
 	}
 	assert.Greater(t, len(seen), 1900,
 		"2000 draws should be nearly all distinct across a ~200k namespace; got %d unique", len(seen))

management/internals/modules/agentnetwork/manager.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"math/rand"
 	"slices"
 	"strings"
 	"sync"
@@ -146,11 +145,6 @@ type managerImpl struct {
 	// of serving proxy can be diffed without re-deriving it.
 	reconcileMu    sync.Mutex
 	reconcileCache map[string]map[string]syntheticMapping
-
-	// labelRngMu guards labelRng. PickUnique consumes math/rand.Source
-	// state; concurrent provider creates would otherwise race.
-	labelRngMu sync.Mutex
-	labelRng   *rand.Rand
 }
 
 // NewManager constructs the persistent Agent Network manager. The
@@ -171,7 +165,6 @@ func NewManager(
 		proxyController:    proxyController,
 		modelDiscovery:     &modeldiscovery.Client{},
 		reconcileCache:     make(map[string]map[string]syntheticMapping),
-		labelRng:           rand.New(rand.NewSource(time.Now().UnixNano())),
 	}
 }
 
@@ -986,9 +979,7 @@ func (m *managerImpl) bootstrapLabeled(ctx context.Context, settings *types.Sett
 	}
 
 	for attempt := 1; attempt <= maxDomainAllocationAttempts; attempt++ {
-		m.labelRngMu.Lock()
-		label := labelgen.PickTuple(m.labelRng)
-		m.labelRngMu.Unlock()
+		label := labelgen.PickTuple()
 		if label == "" {
 			// Only reachable if either word pool were emptied. An empty label
 			// would produce a broken endpoint like ".example.com", so fail