Sign APK without putting keystore info in build.gradle

The nice thing about Groovy is that you can freely mix Java code, and it’s pretty easy to read in a key/value file using java.util.Properties. Perhaps there’s an even easier way using idiomatic Groovy, but Java is still pretty simple.

Create a keystore.properties file (in this example, in the root directory of your project next to settings.gradle, though you can put it wherever you like:

storePassword=...
keyPassword=...
keyAlias=...
storeFile=...

Add this to your build.gradle:

allprojects {
    afterEvaluate { project ->
        def propsFile = rootProject.file('keystore.properties')
        def configName="release"

        if (propsFile.exists() && android.signingConfigs.hasProperty(configName)) {
            def props = new Properties()
            props.load(new FileInputStream(propsFile))
            android.signingConfigs[configName].storeFile = file(props['storeFile'])
            android.signingConfigs[configName].storePassword = props['storePassword']
            android.signingConfigs[configName].keyAlias = props['keyAlias']
            android.signingConfigs[configName].keyPassword = props['keyPassword']
        }
    }
}