Add git sha to jar

Author: henrik242

build.gradle

@@ -105,6 +105,10 @@ tasks.named('jar') {
     manifest.attributes('Multi-Release': 'true')
 }
 
+def gitHashProvider = providers.exec {
+    commandLine 'git', 'rev-parse', '--short', 'HEAD'
+}.standardOutput.asText.map { it.trim() }
+
 shadowJar {
     duplicatesStrategy = DuplicatesStrategy.INCLUDE
     failOnDuplicateEntries = true
@@ -123,6 +127,10 @@ shadowJar {
       duplicatesStrategy = DuplicatesStrategy.EXCLUDE
     }
 
+    manifest {
+      attributes('Implementation-Version': gitHashProvider.get())
+    }
+
     destinationDirectory.set(file('target'))
     archiveBaseName.set('photon')
     archiveClassifier.set('')