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.

Answer 2

I also like having my keystore information on my environment variables, rather than having it inside the project. Your code seems fine, but I was having the same issue with the file path. I solved it by converting that value to string before passing it to file():

signingConfigs {
 debug {
    storeFile file(String.valueOf(System.getenv("KEYSTORE")))
    storePassword System.getenv("KEYSTORE_PASSWORD")
    keyAlias System.getenv("KEY_ALIAS")
    keyPassword System.getenv("KEY_PASSWORD")        
 }

Hope this helps.