Signing product flavors with gradle

You can declare signing config for each flavor in buildType. Here is my gradle file for release signing flavors with different keystores.

android {
  signingConfigs {
    configFirst {
        keyAlias 'alias'
        keyPassword 'password'
        storeFile file('first.keystore')
        storePassword 'password'
    }

    configSecond {
        keyAlias 'alias'
        keyPassword 'password'
        storeFile file('second.keystore')
        storePassword 'password'
    }
  }

  compileSdkVersion 23
  buildToolsVersion "23.0.2"
  defaultConfig {
        minSdkVersion 14
        targetSdkVersion 23
  }

  productFlavors{
    flavor1 {
        applicationId "com.test.firstapp"
    }

    flavor2 {
        applicationId "com.test.secondapp"
    }
  }

  buildTypes {
    release {
        productFlavors.flavor1.signingConfig signingConfigs.configFirst
        productFlavors.flavor2.signingConfig signingConfigs.configSecond           

        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'),
                'proguard-rules.pro'

    }
  }
}

buildTypes block should be placed after productFlavors block, I mean order is important.