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Setting Up Code Signing for iOS Projects

Docker, Machine, and iOS Builds > Setting Up Code Signing for iOS Projects

This document describes the guidelines for setting up code signing for your iOS or Mac project on CircleCI 2.0.

Basic Configuration of iOS Projects

This document assumes that you already have an iOS or Mac project building correctly on CircleCI 2.0. It also assumes that you use Bundle and Fastlane, and have a Gemfile, Appfile and Fastfile checked into your repo.

Note: Setting up code signing on CircleCI 2.0 using Fastlane Match requires adding a User key to your CircleCI project. Setting up code signing is quite different than it was in CircleCI 1.0. The 2.0 documentation has been updated to reflect that the CircleCI app is not used, only the config instructions below are used for code signing in 2.0.

If you have not yet configured your iOS or Mac project on CircleCI 2.0, you can find the configuration instructions in the Testing iOS Applications on macOS document.

Setting up Fastlane Match

Code signing must be configured to generate ad-hoc distributions of your app and App Store builds.

Fastlane Match is one of the Fastlane tools, and it allows for seamless configuration on code signing in both the development environment and on CircleCI. Fastlane Match stores all of your code signing keys and provisioning profiles in a GitHub repository, and downloads and installs the necessary keys and profiles with a single command.

In the root of your repository, run bundle exec fastlane match init and follow the instructions to configure the Match repository. After configuration is complete, run bundle exec fastlane match development to generate and install the Development keys and profiles, and then run bundle exec fastlane match adhoc to generate and install the Ad-hoc distribution keys and profiles.

Preparing Your Xcode Project for use With Fastlane Match

Before setting up Match you must ensure that the code signing settings in your Xcode project are configured as follows:

  • Build Settings -> Code Signing Style is set to Manual
  • Build Settings -> Development Team is set to your development team ID
  • Build Settings -> Code Signing Identity is set to:
    • iOS Developer for the Debug configuration
    • iOS Distribution for the Release configuration

In the target that you will be using for ad-hoc builds:

  • Build Settings -> Provisioning Profile (Deprecated) is set to the Match AdHoc profile.

Adding Match to the Fastlane Lane

On CircleCI, Fastlane Match will need to be run every time you are going to generate an Ad-hoc build of your app. The easiest way to achieve that is to create a custom Fastlane lane just for that. It is best practice to create a Fastfile similar to the following:

Note: For fastlane match to work correctly, you must add setup_circle_ci to before_all in your Fastfile. This ensures that a temporary Fastlane keychain is used.

# fastlane/Fastfile
default_platform :ios

platform :ios do
  before_all do
    setup_circle_ci
  end

  desc "Build and run tests"
  lane :test do
    scan
  end

  desc "Ad-hoc build"
  lane :adhoc do
    match(type: "adhoc")
    gym(export_method: "ad-hoc")
  end
  ...
end

Adding a User key to the CircleCI Project

To enable Fastlane Match to download the certificates and the keys from GitHub, it is necessary to add a user key with access to both the project repo and the certificates / keys repo to the CircleCI project. In the project settings, navigate to Permissions -> Checkout SSH Keys -> Add user key and click Authorize with GitHub.

Note: This action will give the CircleCI project the same GitHub permissions as the user who will be clicking the Authorize with GitHub button.

It is best practice to create a machine user with access to just the project repo and the keys repo, and use that machine user to create a user key to reduce the level of GitHub access granted to the CircleCI project.

After you have added a user key, CircleCI will be able to checkout both the project repo and the code signing certificates / keys repo from GitHub.

Adding the Match Passphrase to the Encrypted Environment Variables

To enable Fastlane Match to decrypt the keys and profiles stored in the GitHub repo, it is necessary to add the encryption passphrase that you configured in the Match setup step to the CircleCI project’s encrypted environment variables.

In the project settings on CircleCI, navigate to Build Settings -> Environment Variables and add the MATCH_PASSWORD variable, and set its value to your encryption passphrase. The passphrase will be stored encrypted at rest.

Invoking the Fastlane Test Lane on CircleCI

After you have configured Match and added its invocation into the Ad-hoc lane, you can run that lane on CircleCI. The following config.yml will create an Ad-hoc build every time you push to the development branch:

# .circleci/config.yml
version: 2
jobs:
  build-and-test:
    macos:
      xcode: "9.0"
    steps:
      ...
      - run: bundle exec fastlane test
      ...

  adhoc:
    macos:
      xcode: "9.0"
    steps:
      ...
      - run: bundle exec fastlane adhoc

workflows:
  version: 2
  build-test-adhoc:
    jobs:
      - build-and-test
      - adhoc:
          filters:
            branches:
              only: development
          requires:
            - build-and-test

Sample Configuration Files

The best practice configuration for setting up code signing for iOS and Mac projects is as follows:

# fastlane/Fastfile
default_platform :ios

platform :ios do
  before_all do
    setup_circle_ci
  end

  desc "Runs all the tests"
  lane :test do
    scan
  end

  desc "Ad-hoc build"
  lane :adhoc do
    match(type: "adhoc")
    gym(export_method: "ad-hoc")
  end
end

# .circleci/config.yml
version: 2
jobs:
  build-and-test:
    macos:
      xcode: "9.0"
    working_directory: /Users/distiller/project
    environment:
      FL_OUTPUT_DIR: output
      FASTLANE_LANE: test
    shell: /bin/bash --login -o pipefail
    steps:
      - checkout
      - run: bundle install
      - run:
          name: Fastlane
          command: bundle exec fastlane $FASTLANE_LANE
      - store_artifacts:
          path: output
      - store_test_results:
          path: output/scan

  adhoc:
    macos:
      xcode: "9.0"
    working_directory: /Users/distiller/project
    environment:
      FL_OUTPUT_DIR: output
      FASTLANE_LANE: adhoc
    shell: /bin/bash --login -o pipefail
    steps:
      - checkout
      - run: bundle install
      - run:
          name: Fastlane
          command: bundle exec fastlane $FASTLANE_LANE
      - store_artifacts:
          path: output

workflows:
  version: 2
  build-test-adhoc:
    jobs:
      - build-and-test
      - adhoc:
          filters:
            branches:
              only: development
          requires:
            - build-and-test

Example Application on GitHub

See the circleci-demo-ios GitHub repository for an example of how to configure code signing for iOS apps using Fastlane Match.

See Also

To read a blog post by Franz Busch at Sixt about their setup for CI with Fastlane and CircleCI, refer to the Continuous integration and delivery with fastlane and CircleCI blog post on Medium.