Staging Version increment automation (opensearch-project#239)

* Version increment automation

Signed-off-by: pgodithi <pgodithi@amazon.com>

* Version increment automation: task rename updateVersion

Signed-off-by: pgodithi <pgodithi@amazon.com>

build.gradle

@@ -27,7 +27,7 @@
 buildscript {
 
     ext {
-        opensearch_version = System.getProperty("opensearch.version", "1.0.0")
+        opensearch_version = System.getProperty("opensearch.version", "1.0.0-SNAPSHOT")
     }
     // This isn't applying from repositories.gradle so repeating it here
     repositories {
@@ -531,3 +531,21 @@ afterEvaluate {
 
 bundlePlugin.mustRunAfter unpackRca
 build.dependsOn unpackRca
+
+// updateVersion: Task to auto increment to the next development iteration
+task updateVersion {
+    onlyIf { System.getProperty('newVersion') }
+    doLast {
+        ext.newVersion = System.getProperty('newVersion')
+        println "Setting version to ${newVersion}."
+        // String tokenization to support -SNAPSHOT
+        ant.replaceregexp(match: opensearch_version.tokenize('-')[0], replace: newVersion.tokenize('-')[0], flags:'g', byline:true) {
+            fileset(dir: projectDir) {
+                // Include the required files that needs to be updated with new Version
+                include(name: ".github/workflows/gradle.yml")
+                include(name: "src/main/resources/plugin-descriptor.properties")
+            }
+        }
+        ant.replaceregexp(file:'build.gradle', match: '"opensearch.version", "\\d.*"', replace: '"opensearch.version", "' + newVersion.tokenize('-')[0] + '-SNAPSHOT"', flags:'g', byline:true)
+    }
+}