src/main/java/net/hostsharing/hsadminng/hs/booking/item/HsBookingItemEntity.java

@@ -34,6 +34,7 @@ import jakarta.persistence.OneToOne;
 import jakarta.persistence.Table;
 import jakarta.persistence.Transient;
 import jakarta.persistence.Version;
+import jakarta.validation.constraints.NotNull;
 import java.io.IOException;
 import java.time.LocalDate;
 import java.util.HashMap;
@@ -92,6 +93,7 @@ public class HsBookingItemEntity implements Stringifyable, RbacObject {
     @JoinColumn(name = "parentitemuuid")
     private HsBookingItemEntity parentItem;
 
+    @NotNull
     @Column(name = "type")
     @Enumerated(EnumType.STRING)
     private HsBookingItemType type;

src/main/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsCloudServerHostingAssetValidator.java

@@ -0,0 +1,23 @@
+package net.hostsharing.hsadminng.hs.hosting.asset.validators;
+
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemType;
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+
+import java.util.regex.Pattern;
+
+class HsCloudServerHostingAssetValidator extends HsHostingAssetEntityValidator {
+
+    HsCloudServerHostingAssetValidator() {
+        super(
+                BookingItem.mustBeOfType(HsBookingItemType.CLOUD_SERVER),
+                ParentAsset.mustBeNull(),
+                AssignedToAsset.mustBeNull(),
+                AlarmContact.isOptional(),
+                NO_EXTRA_PROPERTIES);
+    }
+
+    @Override
+    protected Pattern identifierPattern(final HsHostingAssetEntity assetEntity) {
+        return Pattern.compile("^vm[0-9][0-9][0-9][0-9]$");
+    }
+}

src/main/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsHostingAssetEntityValidator.java

@@ -1,35 +1,80 @@
 package net.hostsharing.hsadminng.hs.hosting.asset.validators;
 
 import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemEntity;
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemType;
 import net.hostsharing.hsadminng.hs.booking.item.validators.HsBookingItemEntityValidatorRegistry;
 import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetType;
+import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactEntity;
 import net.hostsharing.hsadminng.hs.validation.HsEntityValidator;
 import net.hostsharing.hsadminng.hs.validation.ValidatableProperty;
 
+import jakarta.validation.constraints.NotNull;
+import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.regex.Pattern;
+import java.util.stream.Stream;
 
 import static java.util.Arrays.stream;
 import static java.util.Collections.emptyList;
 import static java.util.Optional.ofNullable;
 
-public class HsHostingAssetEntityValidator extends HsEntityValidator<HsHostingAssetEntity> {
+public abstract class HsHostingAssetEntityValidator extends HsEntityValidator<HsHostingAssetEntity> {
 
-    public HsHostingAssetEntityValidator(final ValidatableProperty<?>... properties) {
+    static final ValidatableProperty<?>[] NO_EXTRA_PROPERTIES = new ValidatableProperty<?>[0];
+
+    private final HsHostingAssetEntityValidator.BookingItem bookingItemValidation;
+    private final HsHostingAssetEntityValidator.ParentAsset parentAssetValidation;
+    private final HsHostingAssetEntityValidator.AssignedToAsset assignedToAssetValidation;
+    private final HsHostingAssetEntityValidator.AlarmContact alarmContactValidation;
+
+    HsHostingAssetEntityValidator(
+            @NotNull final BookingItem bookingItemValidation,
+            @NotNull final ParentAsset parentAssetValidation,
+            @NotNull final AssignedToAsset assignedToAssetValidation,
+            @NotNull final AlarmContact alarmContactValidation,
+            final ValidatableProperty<?>... properties) {
         super(properties);
+        this.bookingItemValidation = bookingItemValidation;
+        this.parentAssetValidation = parentAssetValidation;
+        this.assignedToAssetValidation = assignedToAssetValidation;
+        this.alarmContactValidation = alarmContactValidation;
     }
 
-
     @Override
     public List<String> validate(final HsHostingAssetEntity assetEntity) {
         return sequentiallyValidate(
-                () -> validateProperties(assetEntity),
+                () -> validateEntityReferences(assetEntity),
+                () -> validateIdentifierPattern(assetEntity), // might need proper parentAsset or billingItem
                 () -> optionallyValidate(assetEntity.getBookingItem()),
                 () -> optionallyValidate(assetEntity.getParentAsset()),
                 () -> validateAgainstSubEntities(assetEntity)
         );
     }
 
+    private List<String> validateEntityReferences(final HsHostingAssetEntity assetEntity) {
+        return Stream.of(
+                    validateReferencedEntity(assetEntity, "bookingItem", bookingItemValidation::validate),
+                    validateReferencedEntity(assetEntity, "parentAsset", parentAssetValidation::validate),
+                    validateReferencedEntity(assetEntity, "assignedToAsset", assignedToAssetValidation::validate),
+                    validateReferencedEntity(assetEntity, "alarmContact", alarmContactValidation::validate),
+                    validateProperties(assetEntity))
+                .filter(Objects::nonNull)
+                .flatMap(List::stream)
+                .filter(Objects::nonNull)
+                .toList();
+    }
+
+    private List<String> validateReferencedEntity(
+            final HsHostingAssetEntity assetEntity,
+            final String referenceFieldName,
+            final BiFunction<HsHostingAssetEntity, String, List<String>> validator) {
+        return enrich(prefix(assetEntity.toShortString()), validator.apply(assetEntity, referenceFieldName));
+    }
+
     private List<String> validateProperties(final HsHostingAssetEntity assetEntity) {
         return enrich(prefix(assetEntity.toShortString(), "config"), validateProperties(assetEntity.getConfig()));
     }
@@ -73,4 +118,120 @@ public class HsHostingAssetEntityValidator extends HsEntityValidator<HsHostingAs
                 propName, maxValue, propUnit, propName, totalValue, propUnit)
                 : null;
     }
+
+    private List<String> validateIdentifierPattern(final HsHostingAssetEntity assetEntity) {
+        final var expectedIdentifierPattern = identifierPattern(assetEntity);
+        if (!expectedIdentifierPattern.matcher(assetEntity.getIdentifier()).matches()) {
+            return List.of("'identifier' expected to match '"+expectedIdentifierPattern+"', but is '" + assetEntity.getIdentifier() + "'");
         }
+        return Collections.emptyList();
+    }
+
+    protected abstract Pattern identifierPattern(HsHostingAssetEntity assetEntity);
+
+    static abstract class ReferenceValidator<S, T> {
+
+        private final Policy policy;
+        private final T subEntityType;
+        private final Function<HsHostingAssetEntity, S> subEntityGetter;
+        private final Function<S,T> subEntityTypeGetter;
+
+        public ReferenceValidator(
+                final Policy policy,
+                final T subEntityType,
+                final Function<HsHostingAssetEntity, S> subEntityGetter,
+                final Function<S, T> subEntityTypeGetter) {
+            this.policy = policy;
+            this.subEntityType = subEntityType;
+            this.subEntityGetter = subEntityGetter;
+            this.subEntityTypeGetter = subEntityTypeGetter;
+        }
+
+        public ReferenceValidator(
+                final Policy policy,
+                final Function<HsHostingAssetEntity, S> subEntityGetter) {
+            this.policy = policy;
+            this.subEntityType = null;
+            this.subEntityGetter = subEntityGetter;
+            this.subEntityTypeGetter = e -> null;
+        }
+
+        enum Policy {
+            OPTIONAL, FORBIDDEN, REQUIRED
+        }
+
+        List<String> validate(final HsHostingAssetEntity assetEntity, final String referenceFieldName) {
+
+            final var subEntity = subEntityGetter.apply(assetEntity);
+            if (policy == Policy.REQUIRED && subEntity == null) {
+                return List.of(referenceFieldName + "' must not be null but is null");
+            }
+            if (policy == Policy.FORBIDDEN && subEntity != null) {
+                return List.of(referenceFieldName + "' must not be null but is set to "+ assetEntity.getBookingItem().toShortString());
+            }
+            final var subItemType = subEntity != null ? subEntityTypeGetter.apply(subEntity) : null;
+            if (subEntityType != null && subItemType != subEntityType) {
+                return List.of(referenceFieldName + "' must be of type " + subEntityType + " but is of type " + subItemType);
+            }
+            return emptyList();
+        }
+    }
+
+    static class BookingItem extends ReferenceValidator<HsBookingItemEntity, HsBookingItemType> {
+
+        BookingItem(final Policy policy, final HsBookingItemType bookingItemType) {
+            super(policy, bookingItemType, HsHostingAssetEntity::getBookingItem, HsBookingItemEntity::getType);
+        }
+
+        static BookingItem mustBeNull() {
+            return new BookingItem(Policy.FORBIDDEN, null);
+        }
+
+        static BookingItem mustBeOfType(final HsBookingItemType hsBookingItemType) {
+            return new BookingItem(Policy.REQUIRED, hsBookingItemType);
+        }
+    }
+
+    static class ParentAsset extends ReferenceValidator<HsHostingAssetEntity, HsHostingAssetType> {
+
+        ParentAsset(final ReferenceValidator.Policy policy, final HsHostingAssetType parentAssetType) {
+            super(policy, parentAssetType, HsHostingAssetEntity::getParentAsset, HsHostingAssetEntity::getType);
+        }
+
+        static ParentAsset mustBeNull() {
+            return new ParentAsset(Policy.FORBIDDEN, null);
+        }
+
+        static ParentAsset mustBeOfType(final HsHostingAssetType hostingAssetType) {
+            return new ParentAsset(Policy.REQUIRED, hostingAssetType);
+        }
+
+        static ParentAsset mustBeNullOrOfType(final HsHostingAssetType hostingAssetType) {
+            return new ParentAsset(Policy.OPTIONAL, hostingAssetType);
+        }
+    }
+
+    static class AssignedToAsset extends ReferenceValidator<HsHostingAssetEntity, HsHostingAssetType> {
+
+        AssignedToAsset(final ReferenceValidator.Policy policy, final HsHostingAssetType assignedToAssetType) {
+            super(policy, assignedToAssetType, HsHostingAssetEntity::getAssignedToAsset, HsHostingAssetEntity::getType);
+        }
+
+        static AssignedToAsset mustBeNull() {
+            return new AssignedToAsset(Policy.FORBIDDEN, null);
+        }
+    }
+
+    static class AlarmContact extends ReferenceValidator<HsOfficeContactEntity, Enum<?>> {
+
+        AlarmContact(final ReferenceValidator.Policy policy) {
+            super(policy, HsHostingAssetEntity::getAlarmContact);
+        }
+
+        static AlarmContact isOptional() {
+            return new AlarmContact(Policy.OPTIONAL);
+        }
+    }
+
+}
+

src/main/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsHostingAssetEntityValidatorRegistry.java

@@ -14,10 +14,10 @@ public class HsHostingAssetEntityValidatorRegistry {
 
     private static final Map<Enum<HsHostingAssetType>, HsEntityValidator<HsHostingAssetEntity>> validators = new HashMap<>();
     static {
-        register(CLOUD_SERVER, new HsHostingAssetEntityValidator());
+        register(CLOUD_SERVER, new HsCloudServerHostingAssetValidator());
         register(MANAGED_SERVER, new HsManagedServerHostingAssetValidator());
         register(MANAGED_WEBSPACE, new HsManagedWebspaceHostingAssetValidator());
-        register(UNIX_USER, new HsHostingAssetEntityValidator());
+        register(UNIX_USER, new HsUnixUserHostingAssetValidator());
     }
 
     private static void register(final Enum<HsHostingAssetType> type, final HsEntityValidator<HsHostingAssetEntity> validator) {

src/main/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsManagedServerHostingAssetValidator.java

@@ -1,5 +1,10 @@
 package net.hostsharing.hsadminng.hs.hosting.asset.validators;
 
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemType;
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+
+import java.util.regex.Pattern;
+
 import static net.hostsharing.hsadminng.hs.validation.BooleanProperty.booleanProperty;
 import static net.hostsharing.hsadminng.hs.validation.EnumerationProperty.enumerationProperty;
 import static net.hostsharing.hsadminng.hs.validation.IntegerProperty.integerProperty;
@@ -8,6 +13,11 @@ class HsManagedServerHostingAssetValidator extends HsHostingAssetEntityValidator
 
     public HsManagedServerHostingAssetValidator() {
         super(
+                BookingItem.mustBeOfType(HsBookingItemType.MANAGED_SERVER),
+                ParentAsset.mustBeNull(), // until we introduce a hosting asset for 'HOST'
+                AssignedToAsset.mustBeNull(),
+                AlarmContact.isOptional(), // hostmaster alert address is implicitly added
+
                 // monitoring
                 integerProperty("monit_max_cpu_usage").unit("%").min(10).max(100).withDefault(92),
                 integerProperty("monit_max_ram_usage").unit("%").min(10).max(100).withDefault(92),
@@ -15,7 +25,6 @@ class HsManagedServerHostingAssetValidator extends HsHostingAssetEntityValidator
                 integerProperty("monit_min_free_ssd").min(1).max(1000).withDefault(5),
                 integerProperty("monit_max_hdd_usage").unit("%").min(10).max(100).withDefault(95),
                 integerProperty("monit_min_free_hdd").min(1).max(4000).withDefault(10),
-                // stringProperty("monit_alarm_email").unit("GB").optional() TODO.impl: via Contact?
 
                 // other settings
                 // booleanProperty("fastcgi_small").withDefault(false), TODO.spec: clarify Salt-Grains
@@ -45,4 +54,9 @@ class HsManagedServerHostingAssetValidator extends HsHostingAssetEntityValidator
                 booleanProperty("software-imagemagick-ghostscript").withDefault(false)
         );
     }
+
+    @Override
+    protected Pattern identifierPattern(final HsHostingAssetEntity assetEntity) {
+        return Pattern.compile("^vm[0-9][0-9][0-9][0-9]$");
+    }
 }

src/main/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsManagedWebspaceHostingAssetValidator.java

@@ -1,29 +1,22 @@
 package net.hostsharing.hsadminng.hs.hosting.asset.validators;
 
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemType;
 import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetType;
 
-import java.util.Collection;
+import java.util.regex.Pattern;
-import java.util.stream.Stream;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
 
 class HsManagedWebspaceHostingAssetValidator extends HsHostingAssetEntityValidator {
     public HsManagedWebspaceHostingAssetValidator() {
+        super(BookingItem.mustBeOfType(HsBookingItemType.MANAGED_WEBSPACE),
+                ParentAsset.mustBeOfType(HsHostingAssetType.MANAGED_SERVER), // the (shared or private) ManagedServer
+                AssignedToAsset.mustBeNull(),
+                AlarmContact.isOptional(), // hostmaster alert address is implicitly added
+                NO_EXTRA_PROPERTIES);
     }
 
     @Override
-    public List<String> validate(final HsHostingAssetEntity assetEntity) {
+    protected Pattern identifierPattern(final HsHostingAssetEntity assetEntity) {
-        return Stream.of(validateIdentifierPattern(assetEntity), super.validate(assetEntity))
+        return Pattern.compile("^" + assetEntity.getParentAsset().getBookingItem().getProject().getDebitor().getDefaultPrefix() + "[0-9][0-9]$");
-                .flatMap(Collection::stream)
-                .collect(Collectors.toList());
-    }
-
-    private static List<String> validateIdentifierPattern(final HsHostingAssetEntity assetEntity) {
-        final var expectedIdentifierPattern = "^" + assetEntity.getParentAsset().getBookingItem().getProject().getDebitor().getDefaultPrefix() + "[0-9][0-9]$";
-        if ( !assetEntity.getIdentifier().matches(expectedIdentifierPattern)) {
-            return List.of("'identifier' expected to match '"+expectedIdentifierPattern+"', but is '" + assetEntity.getIdentifier() + "'");
-        }
-        return Collections.emptyList();
     }
 }

src/main/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsUnixUserHostingAssetValidator.java

@@ -0,0 +1,23 @@
+package net.hostsharing.hsadminng.hs.hosting.asset.validators;
+
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetType;
+
+import java.util.regex.Pattern;
+
+class HsUnixUserHostingAssetValidator extends HsHostingAssetEntityValidator {
+
+    HsUnixUserHostingAssetValidator() {
+        super(BookingItem.mustBeNull(),
+              ParentAsset.mustBeOfType(HsHostingAssetType.MANAGED_WEBSPACE),
+              AssignedToAsset.mustBeNull(),
+              AlarmContact.isOptional(), // TODO.spec: for quota notifications
+              NO_EXTRA_PROPERTIES); // TODO.spec: yet to be specified
+    }
+
+    @Override
+    protected Pattern identifierPattern(final HsHostingAssetEntity assetEntity) {
+        final var webspaceIdentifier = assetEntity.getParentAsset().getIdentifier();
+        return Pattern.compile("^"+webspaceIdentifier+"$|^"+webspaceIdentifier+"-[a-z0-9]+$");
+    }
+}

src/test/java/net/hostsharing/hsadminng/hs/booking/item/TestHsBookingItem.java

@@ -12,13 +12,21 @@ import static net.hostsharing.hsadminng.hs.booking.project.TestHsBookingProject.
 @UtilityClass
 public class TestHsBookingItem {
 
-    public static final HsBookingItemEntity TEST_BOOKING_ITEM = HsBookingItemEntity.builder()
+    public static final HsBookingItemEntity TEST_MANAGED_SERVER_BOOKING_ITEM = HsBookingItemEntity.builder()
             .project(TEST_PROJECT)
-            .caption("test booking item")
+            .type(HsBookingItemType.MANAGED_SERVER)
+            .caption("test project booking item")
             .resources(Map.ofEntries(
                     entry("someThing", 1),
                     entry("anotherThing", "blue")
             ))
             .validity(Range.closedInfinite(LocalDate.of(2020, 1, 15)))
             .build();
+
+    public static final HsBookingItemEntity TEST_CLOUD_SERVER_BOOKING_ITEM = HsBookingItemEntity.builder()
+            .project(TEST_PROJECT)
+            .type(HsBookingItemType.CLOUD_SERVER)
+            .caption("test cloud server booking item")
+            .validity(Range.closedInfinite(LocalDate.of(2020, 1, 15)))
+            .build();
 }

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/HsHostingAssetEntityPatcherUnitTest.java

@@ -15,7 +15,7 @@ import java.util.Map;
 import java.util.UUID;
 import java.util.stream.Stream;
 
-import static net.hostsharing.hsadminng.hs.booking.item.TestHsBookingItem.TEST_BOOKING_ITEM;
+import static net.hostsharing.hsadminng.hs.booking.item.TestHsBookingItem.TEST_CLOUD_SERVER_BOOKING_ITEM;
 import static net.hostsharing.hsadminng.mapper.PatchMap.entry;
 import static net.hostsharing.hsadminng.mapper.PatchMap.patchMap;
 import static org.junit.jupiter.api.TestInstance.Lifecycle.PER_CLASS;
@@ -70,7 +70,7 @@ class HsHostingAssetEntityPatcherUnitTest extends PatchUnitTestBase<
     protected HsHostingAssetEntity newInitialEntity() {
         final var entity = new HsHostingAssetEntity();
         entity.setUuid(INITIAL_BOOKING_ITEM_UUID);
-        entity.setBookingItem(TEST_BOOKING_ITEM);
+        entity.setBookingItem(TEST_CLOUD_SERVER_BOOKING_ITEM);
         entity.getConfig().putAll(KeyValueMap.from(INITIAL_CONFIG));
         entity.setCaption(INITIAL_CAPTION);
         entity.setAlarmContact(givenInitialContact);

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/HsHostingAssetEntityUnitTest.java

@@ -5,13 +5,13 @@ import org.junit.jupiter.api.Test;
 import java.util.Map;
 
 import static java.util.Map.entry;
-import static net.hostsharing.hsadminng.hs.booking.item.TestHsBookingItem.TEST_BOOKING_ITEM;
+import static net.hostsharing.hsadminng.hs.booking.item.TestHsBookingItem.TEST_CLOUD_SERVER_BOOKING_ITEM;
 import static org.assertj.core.api.Assertions.assertThat;
 
 class HsHostingAssetEntityUnitTest {
 
     final HsHostingAssetEntity givenParentAsset = HsHostingAssetEntity.builder()
-            .bookingItem(TEST_BOOKING_ITEM)
+            .bookingItem(TEST_CLOUD_SERVER_BOOKING_ITEM)
             .type(HsHostingAssetType.MANAGED_SERVER)
             .identifier("vm1234")
             .caption("some managed asset")
@@ -21,7 +21,7 @@ class HsHostingAssetEntityUnitTest {
                     entry("HDD-storage", 2048)))
             .build();
     final HsHostingAssetEntity givenWebspace = HsHostingAssetEntity.builder()
-            .bookingItem(TEST_BOOKING_ITEM)
+            .bookingItem(TEST_CLOUD_SERVER_BOOKING_ITEM)
             .type(HsHostingAssetType.MANAGED_WEBSPACE)
             .parentAsset(givenParentAsset)
             .identifier("xyz00")

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsCloudServerHostingAssetValidatorUnitTest.java

@@ -6,6 +6,7 @@ import org.junit.jupiter.api.Test;
 import java.util.Map;
 
 import static java.util.Map.entry;
+import static net.hostsharing.hsadminng.hs.booking.item.TestHsBookingItem.TEST_CLOUD_SERVER_BOOKING_ITEM;
 import static net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetType.CLOUD_SERVER;
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -28,7 +29,28 @@ class HsCloudServerHostingAssetValidatorUnitTest {
         final var result = validator.validate(cloudServerHostingAssetEntity);
 
         // then
-        assertThat(result).containsExactly("'CLOUD_SERVER:vm1234.config.RAM' is not expected but is set to '2000'");
+        assertThat(result).containsExactlyInAnyOrder(
+                "'CLOUD_SERVER:vm1234.bookingItem' must not be null but is null",
+                "'CLOUD_SERVER:vm1234.config.RAM' is not expected but is set to '2000'");
+    }
+
+    @Test
+    void validatesInvalidIdentifier() {
+        // given
+        final var cloudServerHostingAssetEntity = HsHostingAssetEntity.builder()
+                .type(CLOUD_SERVER)
+                .identifier("xyz99")
+                .bookingItem(TEST_CLOUD_SERVER_BOOKING_ITEM)
+                .build();
+        final var validator = HsHostingAssetEntityValidatorRegistry.forType(cloudServerHostingAssetEntity.getType());
+
+
+        // when
+        final var result = validator.validate(cloudServerHostingAssetEntity);
+
+        // then
+        assertThat(result).containsExactlyInAnyOrder(
+                "'identifier' expected to match '^vm[0-9][0-9][0-9][0-9]$', but is 'xyz99'");
     }
 
     @Test

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsHostingAssetEntityValidatorUnitTest.java

@@ -1,6 +1,9 @@
 package net.hostsharing.hsadminng.hs.hosting.asset.validators;
 
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemEntity;
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemType;
 import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetType;
 import org.junit.jupiter.api.Test;
 
 
@@ -16,12 +19,17 @@ class HsHostingAssetEntityValidatorUnitTest {
         final var managedServerHostingAssetEntity = HsHostingAssetEntity.builder()
                 .type(MANAGED_SERVER)
                 .identifier("vm1234")
+                .bookingItem(HsBookingItemEntity.builder().type(HsBookingItemType.MANAGED_SERVER).build())
+                .parentAsset(HsHostingAssetEntity.builder().type(MANAGED_SERVER).build())
                 .build();
 
         // when
         final var result = catchThrowable( ()-> HsHostingAssetEntityValidatorRegistry.validated(managedServerHostingAssetEntity));
 
         // then
-        assertThat(result).isNull(); // all required properties have defaults
+        assertThat(result.getMessage()).contains(
+                "'MANAGED_SERVER:vm1234.parentAsset' must not be null but is set to D-???????-?:null",
+                "'MANAGED_SERVER:vm1234.assignedToAsset' must not be null but is set to D-???????-?:null"
+        );
     }
 }

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsManagedServerHostingAssetValidatorUnitTest.java

@@ -1,5 +1,7 @@
 package net.hostsharing.hsadminng.hs.hosting.asset.validators;
 
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemEntity;
+import net.hostsharing.hsadminng.hs.booking.item.HsBookingItemType;
 import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
 import org.junit.jupiter.api.Test;
 
@@ -17,6 +19,7 @@ class HsManagedServerHostingAssetValidatorUnitTest {
         final var mangedWebspaceHostingAssetEntity = HsHostingAssetEntity.builder()
                 .type(MANAGED_SERVER)
                 .identifier("vm1234")
+                .bookingItem(HsBookingItemEntity.builder().type(HsBookingItemType.MANAGED_SERVER).build())
                 .config(Map.ofEntries(
                         entry("monit_max_hdd_usage", "90"),
                         entry("monit_max_cpu_usage", 2),
@@ -30,8 +33,28 @@ class HsManagedServerHostingAssetValidatorUnitTest {
 
         // then
         assertThat(result).containsExactlyInAnyOrder(
+                "'MANAGED_SERVER:vm1234.parentAsset' must not be null but is set to D-???????-?:null",
+                "'MANAGED_SERVER:vm1234.assignedToAsset' must not be null but is set to D-???????-?:null",
                 "'MANAGED_SERVER:vm1234.config.monit_max_cpu_usage' is expected to be >= 10 but is 2",
                 "'MANAGED_SERVER:vm1234.config.monit_max_ram_usage' is expected to be <= 100 but is 101",
                 "'MANAGED_SERVER:vm1234.config.monit_max_hdd_usage' is expected to be of type class java.lang.Integer, but is of type 'String'");
     }
+
+    @Test
+    void validatesInvalidIdentifier() {
+        // given
+        final var mangedServerHostingAssetEntity = HsHostingAssetEntity.builder()
+                .type(MANAGED_SERVER)
+                .identifier("xyz00")
+                .bookingItem(HsBookingItemEntity.builder().type(HsBookingItemType.MANAGED_SERVER).build())
+                .build();
+        final var validator = HsHostingAssetEntityValidatorRegistry.forType(mangedServerHostingAssetEntity.getType());
+
+        // when
+        final var result = validator.validate(mangedServerHostingAssetEntity);
+
+        // then
+        assertThat(result).containsExactlyInAnyOrder(
+                "'identifier' expected to match '^vm[0-9][0-9][0-9][0-9]$', but is 'xyz00'");
+    }
 }

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsManagedWebspaceHostingAssetValidatorUnitTest.java

@@ -40,11 +40,12 @@ class HsManagedWebspaceHostingAssetValidatorUnitTest {
             .build();
 
     @Test
-    void validatesIdentifier() {
+    void validatesIdentifierAndReferencedEntities() {
         // given
         final var validator = HsHostingAssetEntityValidatorRegistry.forType(MANAGED_WEBSPACE);
         final var mangedWebspaceHostingAssetEntity = HsHostingAssetEntity.builder()
                 .type(MANAGED_WEBSPACE)
+                .bookingItem(HsBookingItemEntity.builder().type(HsBookingItemType.MANAGED_WEBSPACE).build())
                 .parentAsset(mangedServerAssetEntity)
                 .identifier("xyz00")
                 .build();
@@ -62,6 +63,7 @@ class HsManagedWebspaceHostingAssetValidatorUnitTest {
         final var validator = HsHostingAssetEntityValidatorRegistry.forType(MANAGED_WEBSPACE);
         final var mangedWebspaceHostingAssetEntity = HsHostingAssetEntity.builder()
                 .type(MANAGED_WEBSPACE)
+                .bookingItem(HsBookingItemEntity.builder().type(HsBookingItemType.MANAGED_WEBSPACE).build())
                 .parentAsset(mangedServerAssetEntity)
                 .identifier("abc00")
                 .config(Map.ofEntries(
@@ -82,6 +84,7 @@ class HsManagedWebspaceHostingAssetValidatorUnitTest {
         final var validator = HsHostingAssetEntityValidatorRegistry.forType(MANAGED_WEBSPACE);
         final var mangedWebspaceHostingAssetEntity = HsHostingAssetEntity.builder()
                 .type(MANAGED_WEBSPACE)
+                .bookingItem(HsBookingItemEntity.builder().type(HsBookingItemType.MANAGED_WEBSPACE).build())
                 .parentAsset(mangedServerAssetEntity)
                 .identifier("abc00")
                 .build();

src/test/java/net/hostsharing/hsadminng/hs/hosting/asset/validators/HsUnixUserHostingAssetValidatorUnitTest.java

@@ -0,0 +1,27 @@
+package net.hostsharing.hsadminng.hs.hosting.asset.validators;
+
+import net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetEntity;
+import org.junit.jupiter.api.Test;
+
+import static net.hostsharing.hsadminng.hs.hosting.asset.HsHostingAssetType.UNIX_USER;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HsUnixUserHostingAssetValidatorUnitTest {
+
+    @Test
+    void validatesInvalidIdentifier() {
+        // given
+        final var unixUserHostingAsset = HsHostingAssetEntity.builder()
+                .type(UNIX_USER)
+                .identifier("abc")
+                .build();
+        final var validator = HsHostingAssetEntityValidatorRegistry.forType(unixUserHostingAsset.getType());
+
+
+        // when
+        final var result = validator.validate(unixUserHostingAsset);
+
+        // then
+        assertThat(result).containsExactly("'identifier' expected to match '^vm[0-9][0-9][0-9][0-9]$', but is 'xyz99'");
+    }
+}