Allow . chars in model_id #108426

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/job/messages/Messages.java

@@ -95,7 +95,7 @@ public final class Messages {
     public static final String INCONSISTENT_ID =
         "Inconsistent {0}; ''{1}'' specified in the body differs from ''{2}'' specified as a URL argument";
     public static final String INVALID_ID = "Invalid {0}; ''{1}'' can contain lowercase alphanumeric (a-z and 0-9), hyphens or "
-        + "underscores; must start and end with alphanumeric";
+        + "underscores; must start with alphanumeric or '.' and end with alphanumeric";
     public static final String INVALID_MODEL_PACKAGE_ID = "Invalid {0}; ''{1}'' is not a valid model package id";
     public static final String ID_TOO_LONG = "Invalid {0}; ''{1}'' cannot contain more than {2} characters.";
     public static final String INVALID_GROUP = "Invalid group id ''{0}''; must be non-empty string and may contain lowercase alphanumeric"

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/utils/MlStrings.java

@@ -26,10 +26,11 @@ public final class MlStrings {
     /**
      * Valid user id pattern.
      * Matches a string that contains lower case characters, digits, hyphens, underscores or dots.
-     * The string may start and end only in lower case characters or digits.
+     * The string may start and end only in lower case characters, digits or '.'.
      * Note that '.' is allowed but not documented.
      */
-    private static final Pattern VALID_ID_CHAR_PATTERN = Pattern.compile("[a-z0-9](?:[a-z0-9_\\-\\.]*[a-z0-9])?");
+    private static final Pattern VALID_ID_CHAR_PATTERN =
+        Pattern.compile("^(?:[a-z0-9]|(?:\\.|[a-z0-9])[a-z0-9_\\-.]*[a-z0-9])$");
 
     public static final int ID_LENGTH_LIMIT = 64;
 

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/inference/action/PutInferenceModelActionTests.java

@@ -44,6 +44,17 @@ public void testValidate() {
         ActionRequestValidationException validationException = request.validate();
         assertNull(validationException);
 
+        // valid model ID with . at start
+        var modelWithDotAtStart = new PutInferenceModelAction.Request(
+            TASK_TYPE,
+            "." +MODEL_ID + "_-0",
+            BYTES,
+            X_CONTENT_TYPE,
+            InferenceAction.Request.DEFAULT_TIMEOUT
+        );
+        assertNull(modelWithDotAtStart.validate());
+
+
         // invalid model IDs
 
         var invalidRequest = new PutInferenceModelAction.Request(