[Notification] add method type in CustomWebhook data model

src/main/kotlin/org/opensearch/commons/notifications/model/HttpMethodType.kt

@@ -0,0 +1,36 @@
+package org.opensearch.commons.notifications.model
+
+import org.opensearch.commons.utils.EnumParser
+
+enum class HttpMethodType(val tag: String) {
+    POST("POST") {
+        override fun toString(): String {
+            return tag
+        }
+    },
+    PUT("PUT") {
+        override fun toString(): String {
+            return tag
+        }
+    },
+    PATCH("PATCH") {
+        override fun toString(): String {
+            return tag
+        }
+    };
+
+    companion object {
+        private val tagMap = values().associateBy { it.tag }
+
+        val enumParser = EnumParser { fromTagOrDefault(it) }
+
+        /**
+         * Get HttpMethodType from tag or POST if not found
+         * @param tag the tag
+         * @return MethodType corresponding to tag. POST if invalid tag.
+         */
+        fun fromTagOrDefault(tag: String): HttpMethodType {
+            return tagMap[tag] ?: POST
+        }
+    }
+}

src/main/kotlin/org/opensearch/commons/notifications/model/Webhook.kt

@@ -35,6 +35,7 @@ import org.opensearch.common.xcontent.XContentBuilder
 import org.opensearch.common.xcontent.XContentParser
 import org.opensearch.common.xcontent.XContentParserUtils
 import org.opensearch.commons.notifications.NotificationConstants.HEADER_PARAMS_TAG
+import org.opensearch.commons.notifications.NotificationConstants.METHOD_TAG
 import org.opensearch.commons.notifications.NotificationConstants.URL_TAG
 import org.opensearch.commons.utils.STRING_READER
 import org.opensearch.commons.utils.STRING_WRITER
@@ -47,7 +48,8 @@ import java.io.IOException
  */
 data class Webhook(
     val url: String,
-    val headerParams: Map<String, String> = mapOf()
+    val headerParams: Map<String, String> = mapOf(),
+    val method: HttpMethodType = HttpMethodType.POST
 ) : BaseConfigData {
 
     init {
@@ -77,6 +79,7 @@ data class Webhook(
         fun parse(parser: XContentParser): Webhook {
             var url: String? = null
             var headerParams: Map<String, String> = mapOf()
+            var method = HttpMethodType.POST
 
             XContentParserUtils.ensureExpectedToken(
                 XContentParser.Token.START_OBJECT,
@@ -89,14 +92,15 @@ data class Webhook(
                 when (fieldName) {
                     URL_TAG -> url = parser.text()
                     HEADER_PARAMS_TAG -> headerParams = parser.mapStrings()
+                    METHOD_TAG -> method = HttpMethodType.fromTagOrDefault(parser.text())
                     else -> {
                         parser.skipChildren()
                         log.info("Unexpected field: $fieldName, while parsing Webhook destination")
                     }
                 }
             }
             url ?: throw IllegalArgumentException("$URL_TAG field absent")
-            return Webhook(url, headerParams)
+            return Webhook(url, headerParams, method)
         }
     }
 
@@ -108,6 +112,7 @@ data class Webhook(
         return builder.startObject()
             .field(URL_TAG, url)
             .field(HEADER_PARAMS_TAG, headerParams)
+            .field(METHOD_TAG, method.tag)
             .endObject()
     }
 
@@ -117,7 +122,8 @@ data class Webhook(
      */
     constructor(input: StreamInput) : this(
         url = input.readString(),
-        headerParams = input.readMap(STRING_READER, STRING_READER)
+        headerParams = input.readMap(STRING_READER, STRING_READER),
+        method = input.readEnum(HttpMethodType::class.java)
     )
 
     /**
@@ -126,5 +132,6 @@ data class Webhook(
     override fun writeTo(output: StreamOutput) {
         output.writeString(url)
         output.writeMap(headerParams, STRING_WRITER, STRING_WRITER)
+        output.writeEnum(method)
     }
 }

src/test/kotlin/org/opensearch/commons/notifications/model/WebhookTests.kt

@@ -46,21 +46,30 @@ internal class WebhookTests {
 
     @Test
     fun `Webhook serialize and deserialize using json object should be equal`() {
-        val sampleWebhook = Webhook("https://domain.com/sample_url#1234567890", mapOf(Pair("key", "value")))
+        val sampleWebhook = Webhook(
+            "https://domain.com/sample_url#1234567890",
+            mapOf(Pair("key", "value")),
+            HttpMethodType.PUT
+        )
         val jsonString = getJsonString(sampleWebhook)
         val recreatedObject = createObjectFromJsonString(jsonString) { Webhook.parse(it) }
         assertEquals(sampleWebhook, recreatedObject)
     }
 
     @Test
     fun `Webhook should deserialize json object using parser`() {
-        val sampleWebhook = Webhook("https://domain.com/sample_url#1234567890", mapOf(Pair("key", "value")))
+        val sampleWebhook = Webhook(
+            "https://domain.com/sample_url#1234567890",
+            mapOf(Pair("key", "value")),
+            HttpMethodType.PATCH
+        )
         val jsonString = """
             {
                 "url":"${sampleWebhook.url}",
                 "header_params":{
                     "key":"value"
-                }
+                },
+                "method":"PATCH"
             }
         """.trimIndent()
         val recreatedObject = createObjectFromJsonString(jsonString) { Webhook.parse(it) }