Dockerizing React Native for Deterministic CI/CD Pipelines

The Chaos of Mobile CI/CD

Unlike web applications that build predictably in standard Linux environments, React Native apps usually depend on a massive, brittle ecosystem of Xcode versions, CocoaPods, Ruby versions, and Android NDKs.

If a senior dev has Xcode 15 locally and the CI runner has Xcode 14, the build fails dynamically.

Containerizing the Build Process

We solved this via strict, heavy Dockerization for Android and utilizing Fastlane wrapped in customized macOS GitHub Action runners for iOS.

# Android Builder
FROM ubuntu:22.04

# Install SDKs
ENV ANDROID_HOME=/opt/android-sdk-linux
ENV PATH=$PATH:$ANDROID_HOME/cmdline-tools/latest/bin:$ANDROID_HOME/platform-tools

# Pre-fetch Gradle dependencies
COPY android/ /app/android/
WORKDIR /app/android
RUN ./gradlew dependencies

This guarantees that building v2.4.1 today uses the exact same binaries and environment variables as it will 3 years from now.