In this lesson, you will learn how to automate the management of Apple and Google developer credentials to ensure your app can be signed and distributed without manual intervention.
Why Do We Need Signing?
When you build a mobile app, Apple and Google require proof of who created it. This is done through Code Signing. Think of it like a digital wax seal: it tells the operating system that your app hasn't been tampered with since you built it.
To create this "seal," you need specific files:
- Certificates: These identify you as a trusted developer.
- Provisioning Profiles (iOS): These link your developer certificate to a specific App ID and a list of authorized devices.
- Keystore (Android): A file that holds your cryptographic keys to sign the APK or AAB.
Automating with EAS
Manually managing these files is error-prone. If you lose a certificate, you might not be able to update your app in the App Store! In the Expo ecosystem, we use EAS (Expo Application Services) to handle this automatically via "EAS Credentials."
When you run an automated build, EAS connects to your developer accounts, generates the necessary profiles, and applies them to your build process. You don't have to download .mobileprovision files or manually manage keystores on your local machine.
You can trigger this setup in your terminal:
eas build:configure
# Or to specifically sync your credentials:
eas credentials
When you run eas build, the service checks if your credentials are valid. If they are missing or expired, EAS can automatically generate new ones for you. This means your CI/CD pipeline remains "hands-off"—it handles the secure handshaking with Apple and Google, allowing you to focus purely on your code. By keeping these credentials stored in the cloud, you ensure that anyone on your team with access to the project can trigger a valid, signed build that is ready for the app stores.
Key Takeaway: Code signing provides a secure digital identity for your app, and by using EAS, you can fully automate the generation and storage of these sensitive credentials to enable effortless, reliable deployments.