[Bugfix] GT-103 Ensure pod names not too long (#1053)

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Change Log
 
 ## [master](https://github.com/arangodb/kube-arangodb/tree/master) (N/A)
+- (Bugfix) Ensure pod names not too long
 
 ## [1.2.14](https://github.com/arangodb/kube-arangodb/tree/1.2.14) (2022-07-14)
 - (Feature) Add ArangoSync TLS based rotation

pkg/apis/shared/names.go

@@ -31,6 +31,10 @@ var (
 	arangodPrefixes = []string{"CRDN-", "PRMR-", "AGNT-", "SNGL-"}
 )
 
+const (
+	qualifiedNameMaxLength int = 63
+)
+
 // StripArangodPrefix removes well know arangod ID prefixes from the given id.
 func StripArangodPrefix(id string) string {
 	for _, prefix := range arangodPrefixes {
@@ -43,13 +47,11 @@ func StripArangodPrefix(id string) string {
 
 // FixupResourceName ensures that the given name
 // complies with kubernetes name requirements.
-// If the name is to long or contains invalid characters,
-// if will be adjusted and a hash with be added.
+// If the name is too long or contains invalid characters,
+// it will be adjusted and a hash will be added.
 func FixupResourceName(name string) string {
-	maxLen := 63
-
 	sb := strings.Builder{}
-	needHash := len(name) > maxLen
+	needHash := len(name) > qualifiedNameMaxLength
 	for _, ch := range name {
 		if unicode.IsDigit(ch) || unicode.IsLower(ch) || ch == '-' {
 			sb.WriteRune(ch)
@@ -64,8 +66,8 @@ func FixupResourceName(name string) string {
 	if needHash {
 		hash := sha1.Sum([]byte(name))
 		h := fmt.Sprintf("-%0x", hash[:3])
-		if len(result)+len(h) > maxLen {
-			result = result[:maxLen-(len(h))]
+		if len(result)+len(h) > qualifiedNameMaxLength {
+			result = result[:qualifiedNameMaxLength-(len(h))]
 		}
 		result = result + h
 	}
@@ -75,7 +77,13 @@ func FixupResourceName(name string) string {
 // CreatePodHostName returns the hostname of the pod for a member with
 // a given id in a deployment with a given name.
 func CreatePodHostName(deploymentName, role, id string) string {
-	return deploymentName + "-" + role + "-" + StripArangodPrefix(id)
+	suffix := "-" + role + "-" + StripArangodPrefix(id)
+	maxDeplNameLen := qualifiedNameMaxLength - len(suffix)
+	// shorten deployment name part if resulting name is too big:
+	if maxDeplNameLen > 1 && len(deploymentName) > maxDeplNameLen {
+		deploymentName = deploymentName[:maxDeplNameLen-1]
+	}
+	return deploymentName + suffix
 }
 
 // CreatePersistentVolumeClaimName returns the name of the persistent volume claim for a member with

pkg/apis/shared/names_test.go

@@ -24,10 +24,18 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"k8s.io/apimachinery/pkg/util/validation"
 )
 
 func Test_Names(t *testing.T) {
 	t.Run("Empty", func(t *testing.T) {
 		require.EqualError(t, ValidateResourceName(""), "Name '' is not a valid resource name")
 	})
+	t.Run("Pod name is valid", func(t *testing.T) {
+		name := CreatePodHostName("the-matrix-db", "arangodb-coordinator", "CRDN-549cznuy")
+		require.Empty(t, validation.IsQualifiedName(name))
+
+		name = CreatePodHostName("the-matrix-application-db-instance", "arangodb-coordinator", "CRDN-549cznuy")
+		require.Empty(t, validation.IsQualifiedName(name))
+	})
 }