Automating React Native Deployments

Hi, welcome to Automating React Native Deployments. I am Cecilia Martinez. I am a developer advocate for AppFlow, the CI CD platform built by Ionic. You can feel free to connect with me on Twitter or GitHub, at Cecilia Creates, or on LinkedIn using my name, Cecilia Martinez.

I'm here today to talk to you about shipping React Native apps, specifically the deployment process. For many developers the deployment process is very manual and very complex. You have to prepare your app code for distribution, you have to compile the signed native binary. You also have to deliver that native binary to the app stores, both for iOS and for Android, and deploy that to manual testers in order to actually make sure that your application works as expected. Once you've gone through all of that, you still have to publish your app for all users and ensure that you have ongoing support.

Now there are some benefits to implementing automation into this process. So in this talk we're going to review some ways that you can incrementally implement automation into certain high impact areas of the deployment process. First we'll start talking about configuration. So, one of the areas where you can implement automation in the configuration aspect is to auto-update configuration values like the Build ID. So typically for each new version of your application, you're going to want a fresh build number for iOS and a version code for Android. This can be very tedious to do manually, especially for React Native apps because you need to go into the source code for each of those platforms and update it. Being able to do this automatically in a CI environment makes it much easier and ensures that all your developers are on the same page.

To do this, you can use a tool like Trapeze. Trapeze is a free and open source tool built by Ionic. You can learn more at trapeze.dev. But Trapeze allows you to use YAML to create a file that contains instructions for how you'd like to configure native applications. In this case, we are using a CI build number environment variable. This is typically provided by your CI CD environment. Whether you're using GitHub Actions, CircleCI, or in this case, we're talking about AppFlow, you can update this to be whatever the CI build number environment variable is. We're then matching that CI build number to either the iOS build number or your Android version code, depending on what platform that you're building for. Then in your package.json for your React native app, you will have a script. In this case, we have a CI configure script that will run Trapeze and reference that CI.yaml file that we just looked at. Based on what platform that you're building for, again, this is an environment variable provided by your CI CD provider, you will update either that iOS build number or the Android version code. This is not only helpful to ensure that you always have a fresh build number but it's also good for things like debugging, for testing, and grabbing build blogs from your CI environment because it will always match up to the version code of your app.

Next let's talk about building. If you would decide to automate your build process, it can be really high impact because there's so much that goes into building for native iOS and Android.

You need to trigger the native build. You need to install the dependencies that are required for your build. If you're building for release or for App Store you need to decode and apply signing credentials as well as finally upload that build artifact.

Let's take a look at a GitHub Actions example for a simple Android debug build. This is probably the simplest automated build that you can do. The trigger is workflow dispatch. This is a manual dispatch but you could do things like pushing to a branch or a new commit. We're running on Linux and we're checking out our code.

Here's where we're installing our dependencies. Even though Java and Android Studio is installed in GitHub Actions by default, we do need to set it up to be the correct version to correspond to our React Native app. We also want to cache Gradle for improved performance. We're also installing the dependencies that we need for React Native. In this next step here we're bundling the app. This is required before you actually build when you're doing Android debug. Then we're going to use Gradle to actually create that native assemble debug binary. Ultimately we want to ensure that that APK file gets out of our build environment. We're using the upload build artifact GitHub Action. We're also passing through that path in order to be able to access that APK file.

Now, as I mentioned, this is about the simplest one you can do. It's an Android debug build. We don't need any signing credentials. If you're doing an Android release build or any kind of iOS build, not for simulators, then it gets a lot more complicated. For Android, you'll need to specify your keystore file, password, key alias, and key password in your build.gradle file. However, the more complicated part is ensuring that these files and passwords are available in your CI environment. Because it's a file and not just a text-based password, you're going to need to actually encode that in base64 and then decode that in part of your build process. For iOS, for example, this is what it looks like with GitHub Actions. You have in your secrets, you have your store base64 certificate and provisioning profile as well as the passwords, but then you also do need to encode and decode that. Because this can get super complicated and easy to mess up, I highly recommend that you use signing credentials tooling. This can be pre-built steps or actions, so if you're using GitHub Actions or it could be incorporated into like CircleCI for your CI-CD environment, or you can use a tool for cloud credentials management like Fastlane Match or AppFlow. As an example, in AppFlow, you can upload your Android and iOS credentials that are stored on AppFlow servers.

Then, whenever you create a new build, you automatically apply the signing certificate that corresponds to the target platform and build type. So we handle all of that decoding and encoding for you, so that you don't have to worry about it as part of your build.

Finally, let's take a look at uploading and testing and how you can incorporate automation here. Now, whenever you want to distribute the binaries that you've just created to your manual testers, you'll typically use Google Play Console or App Store Connect in order to distribute to testing tracks or to test flight. If you want to do this automatically, this upload step, you can leverage App Store Developer APIs. You can also use a CICD integration tool like Fastlane. Or you can also use a mobile CICD platform like Bitrise or AppFlow to automate this upload step.

Let's take a look at Fastlane first. Fastlane is an open source tool currently maintained by Google. You can learn more at docs.fastlane.tools. With Fastlane, you create a kinda yaml-type file called a FAST file, but it has its own syntax. So, in the first lane, as you can see here, we have a number of steps that we're performing. We're gonna increment the build number, we're gonna build the app, and then we're gonna upload it to TestFlight. These are steps that are provided by Fastlane. However, you do need to ensure that your credentials and everything is set up in your environment so that you can actually connect to your App Store Connect account.

If you're using a mobile CICD platform such as AppFlow, you can create an automation that also connects to your App Store Connect account. So here, we have a TestFlight automation that whenever we push to our Git main branch, it creates a new iOS App Store build using our signing certificate, and then it uploads it to the App Store to our TestFlight destination. This means that every time I push a change, a new version is uploaded to App Store Connect and is immediately available to all of my TestFlight testers.

Well, we covered a lot in a very short time, so if you are looking for more ways to automate your React Native deployments, check out this free ebook, Solving Mobile CICD with AppFlow, using the link of the QR code on the screen. And feel free to reach out to me if you have any questions. Again, I'm at Cecilia Creates.