Proper way to use System environment variables in gradle using Android Studio

Question

I am using Android Studio to build my project on an Ubuntu 14.04 system.

I wrote the following in my build.gradle files to avoid hardcoding storeFile, storePassword,

Answer 1

Create a gradle.properties file in your source folder (alongside build.gradle) to apply only to the current project or in ~/.gradle/gradle.properties to apply system-wide with the contents:

keystore=/home/myname/keystore/mykey
keystore_password=mypass
key_alias=mykey
key_password=keypass

Now update your build.gradle file with:

debug {
  storeFile file("${keystore}")
  storePassword "${keystore_password}"
  keyAlias "${key_alias}"
  keyPassword "${key_password}"
}

Optionally, you could pass the parameters from command-line with the -P option. For example, ./gradlew assemble -Pkey_password=keypass.