roachprod, roachtest: use same cluster name sanitization

Previously, roachtest had it's own function to sanitize
cluster names, while roachprod had it's own function to
verify cluster names. This change removes both and opts
instead to use vm.DNSSafeName.

This change also introduces MalformedClusterNameError
which gives a hint on what is wrong with the name and
tells roachtest not to retry cluster creation.

pkg/cmd/roachtest/cluster.go

@@ -532,15 +532,8 @@ func (r *clusterRegistry) destroyAllClusters(ctx context.Context, l *logger.Logg
 	}
 }
 
-func makeGCEClusterName(name string) string {
-	name = strings.ToLower(name)
-	name = regexp.MustCompile(`[^-a-z0-9]+`).ReplaceAllString(name, "-")
-	name = regexp.MustCompile(`-+`).ReplaceAllString(name, "-")
-	return name
-}
-
 func makeClusterName(name string) string {
-	return makeGCEClusterName(name)
+	return vm.DNSSafeName(name)
 }
 
 // MachineTypeToCPUs returns a CPU count for GCE, AWS, and Azure machine types.
@@ -973,6 +966,9 @@ func (f *clusterFactory) newCluster(
 			// or a destroy from the previous iteration failed.
 			return nil, nil, err
 		}
+		if errors.HasType(err, (*roachprod.MalformedClusterNameError)(nil)) {
+			return nil, nil, err
+		}
 
 		l.PrintfCtx(ctx, "cluster creation failed, cleaning up in case it was partially created: %s", err)
 		c.Destroy(ctx, closeLogger, l)

pkg/roachprod/roachprod.go

@@ -66,6 +66,21 @@ const (
 	prometheusHostUrlEnv = "COCKROACH_PROM_HOST_URL"
 )
 
+// MalformedClusterNameError is returned when the cluster name passed to Create is invalid.
+type MalformedClusterNameError struct {
+	name        string
+	reason      string
+	suggestions []string
+}
+
+func (e *MalformedClusterNameError) Error() string {
+	return fmt.Sprintf("Malformed cluster name %s, %s. Did you mean one of %s", e.name, e.reason, e.suggestions)
+}
+
+// _findActiveAccounts is a test only variable, used for mocking a provider finding
+// active accounts in a unit test, where we don't want to actually access a provider.
+var _findActiveAccounts func(l *logger.Logger) (map[string]string, error)
+
 // verifyClusterName ensures that the given name conforms to
 // our naming pattern of "<username>-<clustername>". The
 // username must match one of the vm.Provider account names
@@ -75,12 +90,9 @@ func verifyClusterName(l *logger.Logger, clusterName, username string) error {
 		return fmt.Errorf("cluster name cannot be blank")
 	}
 
-	alphaNum, err := regexp.Compile(`^[a-zA-Z0-9\-]+$`)
-	if err != nil {
-		return err
-	}
-	if !alphaNum.MatchString(clusterName) {
-		return errors.Errorf("cluster name must match %s", alphaNum.String())
+	sanitizedName := vm.DNSSafeName(clusterName)
+	if sanitizedName != clusterName {
+		return &MalformedClusterNameError{name: clusterName, reason: "invalid characters", suggestions: []string{sanitizedName}}
 	}
 
 	if config.IsLocalClusterName(clusterName) {
@@ -90,17 +102,29 @@ func verifyClusterName(l *logger.Logger, clusterName, username string) error {
 	// Use the vm.Provider account names, or --username.
 	var accounts []string
 	if len(username) > 0 {
-		accounts = []string{username}
+		cleanAccount := vm.DNSSafeName(username)
+		if cleanAccount != username {
+			l.Printf("WARN: using `%s' as username instead of `%s'", cleanAccount, username)
+		}
+		accounts = []string{cleanAccount}
 	} else {
 		seenAccounts := map[string]bool{}
-		active, err := vm.FindActiveAccounts(l)
+		var active map[string]string
+		var err error
+		if _findActiveAccounts != nil {
+			// Test only path used by unit tests.
+			active, err = _findActiveAccounts(l)
+		} else {
+			active, err = vm.FindActiveAccounts(l)
+		}
+
 		if err != nil {
 			return err
 		}
 		for _, account := range active {
 			if !seenAccounts[account] {
 				seenAccounts[account] = true
-				cleanAccount := vm.DNSSafeAccount(account)
+				cleanAccount := vm.DNSSafeName(account)
 				if cleanAccount != account {
 					l.Printf("WARN: using `%s' as username instead of `%s'", cleanAccount, account)
 				}
@@ -118,26 +142,28 @@ func verifyClusterName(l *logger.Logger, clusterName, username string) error {
 
 	// Try to pick out a reasonable cluster name from the input.
 	var suffix string
+	var reason string
 	if i := strings.Index(clusterName, "-"); i != -1 {
 		// The user specified a username prefix, but it didn't match an active
 		// account name. For example, assuming the account is "peter", `roachprod
 		// create joe-perf` should be specified as `roachprod create joe-perf -u
 		// joe`.
 		suffix = clusterName[i+1:]
+		reason = "username prefix does not match an active account name"
 	} else {
 		// The user didn't specify a username prefix. For example, assuming the
 		// account is "peter", `roachprod create perf` should be specified as
 		// `roachprod create peter-perf`.
 		suffix = clusterName
+		reason = "cluster name should start with a username prefix: <username>-<clustername>"
 	}
 
 	// Suggest acceptable cluster names.
 	var suggestions []string
 	for _, account := range accounts {
 		suggestions = append(suggestions, fmt.Sprintf("%s-%s", account, suffix))
 	}
-	return fmt.Errorf("malformed cluster name %s, did you mean one of %s",
-		clusterName, suggestions)
+	return &MalformedClusterNameError{name: clusterName, reason: reason, suggestions: suggestions}
 }
 
 func sortedClusters() []string {

pkg/roachprod/roachprod_test.go

@@ -0,0 +1,81 @@
+// Copyright 2024 The Cockroach Authors.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package roachprod
+
+import (
+	"io"
+	"testing"
+
+	"github.com/cockroachdb/cockroach/pkg/roachprod/logger"
+	"github.com/stretchr/testify/assert"
+)
+
+func nilLogger() *logger.Logger {
+	lcfg := logger.Config{
+		Stdout: io.Discard,
+		Stderr: io.Discard,
+	}
+	l, err := lcfg.NewLogger("" /* path */)
+	if err != nil {
+		panic(err)
+	}
+	return l
+}
+
+func TestVerifyClusterName(t *testing.T) {
+	_findActiveAccounts = func(l *logger.Logger) (map[string]string, error) {
+		return map[string]string{"1": "user1", "2": "user2", "3": "USER4"}, nil
+	}
+	defer func() {
+		_findActiveAccounts = nil
+	}()
+	cases := []struct {
+		description, clusterName, username string
+		errorExpected                      bool
+	}{
+		{
+			"username found", "user1-clustername", "", false,
+		},
+		{
+			"username not found", "user3-clustername", "", true,
+		},
+		{
+			"specified username", "user3-clustername", "user3", false,
+		},
+		{
+			"specified username that doesn't match", "user1-clustername", "fakeuser", true,
+		},
+		{
+			"clustername not sanitized", "UserName-clustername", "", true,
+		},
+		{
+			"no username", "clustername", "", true,
+		},
+		{
+			"no clustername", "user1", "", true,
+		},
+		{
+			"unsanitized found username", "user4-clustername", "", false,
+		},
+		{
+			"unsanitized specified username", "user3-clustername", "USER3", false,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.description, func(t *testing.T) {
+			if c.errorExpected {
+				assert.Error(t, verifyClusterName(nilLogger(), c.clusterName, c.username))
+			} else {
+				assert.NoError(t, verifyClusterName(nilLogger(), c.clusterName, c.username))
+			}
+		})
+	}
+}

pkg/roachprod/vm/vm.go

@@ -710,21 +710,31 @@ func ExpandZonesFlag(zoneFlag []string) (zones []string, err error) {
 	return zones, nil
 }
 
-// DNSSafeAccount takes a string and returns a cleaned version of the string that can be used in DNS entries.
+// DNSSafeName takes a string and returns a cleaned version of the string that can be used in DNS entries.
 // Unsafe characters are dropped. No length check is performed.
-func DNSSafeAccount(account string) string {
+func DNSSafeName(name string) string {
 	safe := func(r rune) rune {
 		switch {
 		case r >= 'a' && r <= 'z':
 			return r
 		case r >= 'A' && r <= 'Z':
 			return unicode.ToLower(r)
+		case r >= '0' && r <= '9':
+			return r
+		case r == '-':
+			return r
 		default:
 			// Negative value tells strings.Map to drop the rune.
 			return -1
 		}
 	}
-	return strings.Map(safe, account)
+	name = strings.Map(safe, name)
+
+	// DNS entries cannot start or end with hyphens.
+	name = strings.Trim(name, "-")
+
+	// Consecutive hyphens are allowed in DNS entries, but disallow it for readability.
+	return regexp.MustCompile(`-+`).ReplaceAllString(name, "-")
 }
 
 // SanitizeLabel returns a version of the string that can be used as a label.

pkg/roachprod/vm/vm_test.go

@@ -132,12 +132,18 @@ func TestDNSSafeAccount(t *testing.T) {
 			"dot and underscore", "u.ser_n.a_me", "username",
 		},
 		{
-			"Unicode and other characters", "~/❦u.ser_ऄn.a_meλ", "username",
+			"leading and trailing hyphens", "--username-clustername-&", "username-clustername",
+		},
+		{
+			"consecutive hyphens", "username---clustername", "username-clustername",
+		},
+		{
+			"Unicode and other characters", "~/❦--u.ser_ऄn.a_meλ", "username",
 		},
 	}
 	for _, c := range cases {
 		t.Run(c.description, func(t *testing.T) {
-			assert.EqualValues(t, DNSSafeAccount(c.input), c.expected)
+			assert.EqualValues(t, c.expected, DNSSafeName(c.input))
 		})
 	}
 }