Sign APK with credentials from keystore.properties

server/build.gradle

@@ -10,10 +10,26 @@ android {
         versionName "1.24"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
+    signingConfigs {
+        release {
+            // to be defined in server/keystore.properties (see server/HOWTO_keystore.txt)
+            def keystorePropsFile = rootProject.file("server/keystore.properties")
+            if (keystorePropsFile.exists()) {
+                def props = new Properties()
+                props.load(new FileInputStream(keystorePropsFile))
+
+                storeFile rootProject.file(props['storeFile'])
+                storePassword props['storePassword']
+                keyAlias props['keyAlias']
+                keyPassword props['keyPassword']
+            }
+        }
+    }
     buildTypes {
         release {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            signingConfig signingConfigs.release
         }
     }
 }