[Backport 1.x] Add support for minimum compatible version for Extensions and OpenSearch

DESIGN.md

@@ -46,12 +46,11 @@ Here is an example extension configuration `extensions.yml`:
 extensions:
   - name: sample-extension // extension name
     uniqueId: opensearch-sdk-1 // identifier for the extension
-    hostName: 'sdk_host' // name of the host where extension is running
     hostAddress: '127.0.0.1' // host to reach
     port: '4532' // port to reach
     version: '1.0' // extension version
-    description: Extension for the Opensearch SDK Repo // description of the extension
-    opensearchVersion: '3.0.0' // OpenSearch compatibility
+    opensearchVersion: '3.0.0' // Compiled with OpenSearch version
+    minimumCompatibleVersion: '3.0.0' // Minimum version of OpenSearch the extension is wire compatible with
 ```
 
 ### Communication
@@ -74,6 +73,10 @@ The sequence diagram below shows the process of initializing an Extension, regis
 
 The `org.opensearch.sdk.sample` package contains a sample `HelloWorldExtension` implementing the below steps. It is executed following the steps in the [`DEVELOPER_GUIDE`](DEVELOPER_GUIDE.md).
 
+#### Wire Compatibility
+
+Extensions will be wire compatible across minor and patch versions. The configuration contains `minimumCompatibleVersion` which is validated by ExtensionsManager in OpenSearch.
+
 #### Extension REST Actions Walk Through
 
 ![](Docs/ExtensionRestActions.svg)

DEVELOPER_GUIDE.md

@@ -102,16 +102,11 @@ A sample `extensions.yml` file is shown below. The `uniqueId` will be used in RE
 extensions:
   - name: hello-world
     uniqueId: opensearch-sdk-java-1
-    hostName: 'sdk_host'
     hostAddress: '127.0.0.1'
     port: '4532'
     version: '1.0'
-    description: Extension for the Opensearch SDK Repo
     opensearchVersion: '3.0.0'
-    javaVersion: '14'
-    className: ExtensionsRunner
-    customFolderName: opensearch-sdk-java
-    hasNativeController: false
+    minimumCompatibleVersion: '3.0.0'
 ```
 
 #### Run OpenSearch

src/test/java/org/opensearch/sdk/TestExtensionsRunner.java

@@ -111,13 +111,10 @@ public void testHandleExtensionInitRequest() throws UnknownHostException {
         DiscoveryExtensionNode extension = new DiscoveryExtensionNode(
             EXTENSION_NAME,
             "opensearch-sdk-1",
-            "",
-            "",
-            "",
             sourceNode.getAddress(),
             new HashMap<String, String>(),
-            null,
-            null,
+            Version.fromString("3.0.0"),
+            Version.fromString("3.0.0"),
             new ArrayList<ExtensionDependency>()
         );