Fixed regex. Moved cluster-related regexes.

Signed-off-by: AWSHurneyt <hurneyt@amazon.com>

src/main/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInput.kt

@@ -4,7 +4,7 @@ import org.apache.commons.validator.routines.UrlValidator
 import org.apache.hc.core5.net.URIBuilder
 import org.opensearch.common.CheckedFunction
 import org.opensearch.commons.alerting.util.CommonUtilsException
-import org.opensearch.commons.alerting.util.ValidationHelpers.Companion.CLUSTER_NAME_REGEX
+import org.opensearch.commons.utils.CLUSTER_NAME_REGEX
 import org.opensearch.core.ParseField
 import org.opensearch.core.common.io.stream.StreamInput
 import org.opensearch.core.common.io.stream.StreamOutput

src/main/kotlin/org/opensearch/commons/utils/ValidationHelpers.kt

@@ -8,6 +8,24 @@ package org.opensearch.commons.utils
 import java.net.URL
 import java.util.regex.Pattern
 
+/**
+ * This regex asserts that the string:
+ *  Starts with a lowercase letter, or digit
+ *  Contains a sequence of characters followed by an optional colon and another sequence of characters
+ *  The sequences of characters can include lowercase letters, uppercase letters, digits, underscores, or hyphens
+ *  The total length of the string can range from 1 to 255 characters
+ */
+val CLUSTER_NAME_REGEX = Regex("^(?=.{1,255}$)[a-z0-9]([a-zA-Z0-9_-]*:?[a-zA-Z0-9_-]*)$")
+
+/**
+ * This regex asserts that the string:
+ *  Starts with a lowercase letter, digit, or asterisk
+ *  Contains a sequence of characters followed by an optional colon and another sequence of characters
+ *  The sequences of characters can include lowercase letters, uppercase letters, digits, underscores, asterisks, or hyphens
+ *  The total length of the string can range from 1 to 255 characters
+ */
+val CLUSTER_PATTERN_REGEX = Regex("^(?=.{1,255}$)[a-z0-9*]([a-zA-Z0-9_*-]*:?[a-zA-Z0-9_*-]*)$")
+
 // Valid ID characters = (All Base64 chars + "_-") to support UUID format and Base64 encoded IDs
 private val VALID_ID_CHARS: Set<Char> = (('a'..'z') + ('A'..'Z') + ('0'..'9') + '+' + '/' + '_' + '-').toSet()