Google Play Store, publishing a hybrid application

2016-07-06 ,
by DryKISS
Read time: 03 min

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Introduction
Thor
Certification
Clean up
Configuration
Location of APK
Manual Signing
Google Play Store
APK upload
Application listing
Helpful links

Introduction

Within this article we want to describe the best practices for publishing a Hybrid application to the Google Play Store. A hybrid app is one that is created through Cordova or Ionic for instance.

Thor

A Thor task runner command set will be created to wrap all of these processes into some easy to remember commands. These will be listed within each section also.

Running the thor list command in the thor folder of a CodeBlender project will show up the specific Cordova commands.

$ thor list

Certification

As with most publishing to commercial stores there is always a process of certification that must be undertook. This is sometimes called application signing

Google has the following credentials that need generating

Identity certificate : Public key of a public/private key pair.
Keystore : A keystore is a binary file that contains one or more private keys

You must use the same certificate throughout the lifespan of your app in order for users to be able to install new versions as updates to the app

Most of the Google instructions point to using Android Studio to generate signed APKs for distribution. We can also manually sign the application, see below. This probably suits the Cordova life cycle than opening up Studio.

Clean up

Before we build a signed version of the app, it is important to clean up the build to remove any development artefacts. For instance the cordova console.

$ cordova plugin rm cordova-plugin-console

Place the clean-up removal items in a build script.

Configuration

Edit the config.xml to fit the requirements of the deployed application. An important component of this is how to manage the version number, from initial release to how the app is updated in a cross-platform way. There are quite a few hidden complexities to this.

Location of APK

Cordova stores the APK in the following directory

platforms/android/build/outputs/apk

The applications could be called something like

android-debug.apk
android-debug-unaligned.apk

Manual Signing

To manually sign we should follow these steps.

Generate a private key using the keytool command :

$ keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000

It will ask the following questions:

Enter keystore password : dkCordova15
First and last name : Ian Warner
Organizational unit : DryKISS Ltd
Organizational : DryKISS Ltd
City : London
State : London
Two letter country code : UK

This will create my-release-key.keystore

Compile the app in release mode - this generates an unsigned APK

$ cordova build --release android

Sign the unsigned app with JarSigner This should already be installed, if your Mac has updated the JDK.

$ jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore my-release-key.keystore my_application.apk alias_name

Verify that the APK is correctly signed

$ jarsigner -verify -verbose -certs my_application.apk

Align the APK

$ zipalign -v 4 your_project_name-unaligned.apk your_project_name.apk