ATLAS-3735: CustomAttribute length validation bypass for keys with special prefix.

intg/src/main/java/org/apache/atlas/AtlasConfiguration.java

@@ -64,6 +64,8 @@ public enum AtlasConfiguration {
 
     CUSTOM_ATTRIBUTE_KEY_MAX_LENGTH("atlas.custom.attribute.key.max.length", 50),
     CUSTOM_ATTRIBUTE_VALUE_MAX_LENGTH("atlas.custom.attribute.value.max.length", 500),
+    CUSTOM_ATTRIBUTE_KEY_SPECIAL_PREFIX("atlas.custom.attribute.special.prefix", ""),
+
     LABEL_MAX_LENGTH("atlas.entity.label.max.length", 50),
     IMPORT_TEMP_DIRECTORY("atlas.import.temp.directory", ""),
     MIGRATION_IMPORT_START_POSITION("atlas.migration.import.start.position", 0),

repository/src/main/java/org/apache/atlas/repository/store/graph/v2/EntityGraphMapper.java

@@ -119,6 +119,8 @@ public class EntityGraphMapper {
     private static final String  SOFT_REF_FORMAT                   = "%s:%s";
     private static final int     INDEXED_STR_SAFE_LEN              = AtlasConfiguration.GRAPHSTORE_INDEXED_STRING_SAFE_LENGTH.getInt();
     private static final boolean WARN_ON_NO_RELATIONSHIP           = AtlasConfiguration.RELATIONSHIP_WARN_NO_RELATIONSHIPS.getBoolean();
+    private static final String  CUSTOM_ATTRIBUTE_KEY_SPECIAL_PREFIX = AtlasConfiguration.CUSTOM_ATTRIBUTE_KEY_SPECIAL_PREFIX.getString();
+
     private static final String  CLASSIFICATION_NAME_DELIMITER     = "|";
     private static final Pattern CUSTOM_ATTRIBUTE_KEY_REGEX        = Pattern.compile("^[a-zA-Z0-9_-]*$");
     private static final Pattern LABEL_REGEX                       = Pattern.compile("^[a-zA-Z0-9_-]*$");
@@ -2529,6 +2531,10 @@ public class EntityGraphMapper {
                     throw new AtlasBaseException(AtlasErrorCode.INVALID_CUSTOM_ATTRIBUTE_KEY_CHARACTERS, key);
                 }
 
+                if (StringUtils.isNotEmpty(CUSTOM_ATTRIBUTE_KEY_SPECIAL_PREFIX) && key.startsWith(CUSTOM_ATTRIBUTE_KEY_SPECIAL_PREFIX)) {
+                    continue;
+                }
+
                 if (value.length() > CUSTOM_ATTRIBUTE_VALUE_MAX_LENGTH) {
                     throw new AtlasBaseException(AtlasErrorCode.INVALID_CUSTOM_ATTRIBUTE_VALUE, value, String.valueOf(CUSTOM_ATTRIBUTE_VALUE_MAX_LENGTH));
                 }