iOS build process
This page describes the process of building iOS projects with EAS Build. You may want to read this if you are interested in the implementation details of the build service.
Let's take a closer look at the steps for building iOS projects with EAS Build. We'll first run some steps on your local machine to prepare the project and then we'll actually build the project on a remote service.
The first phase happens on your computer. EAS CLI is in charge of completing the following steps:
cli.requireCommit is set to
true in eas.json, check if the git index is clean - this means that there aren't any uncommitted changes. If it's not clean, EAS CLI will provide an option to commit local changes for you or abort the build process.
Prepare the credentials needed for the build.
- Depending on the value of
builds.ios.PROFILE_NAME.credentialsSource, the credentials are obtained from either the local credentials.json file or from the EAS servers. If the
remote mode is selected but no credentials exist yet, you're offered to generate them.
Bare projects require an additional step: check whether the Xcode project is configured to be buildable on the EAS servers (i.e. ensure the correct bundle identifier and Apple Team ID are set).
Create the tarball containing a copy of the repository. Actual behavior depends on the VCS workflow you are using. Learn more here
Upload the project tarball to a private AWS S3 bucket and send the build request to EAS Build.
In this next phase, this is what happens when EAS Build picks up your request:
Create a new macOS VM for the build.
- Every build gets its own fresh macOS VM with all build tools installed there (Xcode, Fastlane, and so on).
Download the project tarball from a private AWS S3 bucket and unpack it.
eas-build-pre-install script from package.json if defined.
npm install in the project root (or
yarn install if
expo doctor to diagnose potential issues with your project configuration.
Restore the credentials
- Create a new keychain.
- Import the Distribution Certificate into the keychain.
- Write the Provisioning Profile to the
~/Library/MobileDevice/Provisioning Profiles directory.
- Verify that the Distribution Certificate and Provisioning Profile match (every Provisioning Profile is assigned to a particular Distribution Certificate and cannot be used for building the iOS with any other certificate).
Managed projects require an additional step: Run
expo prebuild to convert the project to a bare one.
Restore a previously saved cache identified by the
value in the build profile. (Learn more
pod install in the ios directory inside your project.
eas-build-post-install script from package.json if defined.
Update the Xcode project with the ID of the Provisioning Profile.
in the ios
directory if it does not
already exist (check out the Default Gymfile
fastlane gym in the ios directory.
eas-build-pre-upload-artifacts script from package.json if defined.
Store a cache of files and directories defined in the build profile.
is cached by default. Subsequent builds will restore this cache. (Learn more
Upload the build artifact to a private AWS S3 bucket.
- The artifact path can be configured in eas.json at
builds.ios.PROFILE_NAME.artifactPath. It defaults to ios/build/App.ipa. You can specify a glob-like pattern for
artifactPath. We're using the fast-glob package under the hood.
EAS Build can use your own Gymfile. All you need to do is to place this file in the ios directory.
ios/Gymfile file doesn't exist, the iOS builder creates a default one. It looks something like this:
"com.expo.eas.builds.test.application" => "dd83ed9c-4f89-462e-b901-60ae7fe6d737"
export_xcargs "OTHER_CODE_SIGN_FLAGS=\"--keychain /tmp/path/to/keychain\""