Factor out all common spark/hadoop properties

Problem We currently largely overlapping spark.gradle files especially in terms of spark properties.

$ git ls-files | grep spark.gradle
gradle/spark.gradle
helloworld/gradle/spark.gradle
templates/simple/spark.gradle

Solution Provide a way to have a single spark.gradle or at least a single spark-transmogrifai.conf file with common properties that is passed via --properties-file to Spark.

Alternatives

• common properties file
• refactored spark.gradle

Additional context DRY