In this post I'll show you how to set up GitLab CI for your iOS projects, step-by-step, from start to finish.
Continuous integration (CI) is great tool for helping developers be more productive and write higher- quality code. By automatically running a suite of tests every time a commit is pushed, everyone can see the results of changes to the codebase, and take action to make integration faster and easier.
GitLab comes with CI built-in for all projects, for free.
It's beyond the scope of this tutorial to go into details on best practices, workflows, and advantages/disadvantages of CI. In short, however, here's what happens when you enable it for your Xcode project:
- You make changes to your copy of the codebase and push a commit to GitLab.
- GitLab recognizes that the codebase has changed.
- GitLab triggers a build with the GitLab Runner you set up on your Mac for the project.
- The GitLab Runner runs through the build and test process you specified in
- The GitLab Runner reports its results back to GitLab.
- GitLab shows you the results of the build.
This post builds on Jeremy White's blog post, going into a little more detail and correcting some steps for the environment described in the next section.
Assumptions and environment
This post will provide a step-by-step guide to setting up GitLab CI for your iOS projects, from start to finish. First, however, we need to make a few assumptions.
GitLab's strategy document hinges on one key idea: everyone can contribute. As such, this post is written for readers of nearly all levels of experience. However, given that CI is a relatively advanced topic, we're going to assume some basic knowledge of how to create Xcode and GitLab projects, as well as some familiarity with Terminal and git.
This post was written with the following development environment in mind:
- A Mac running OS X 10.11.3 "El Capitan"
- Xcode 7.2.1 with command-line tools and the iOS 9.2 SDK installed
- GitLab.com v8.5
We'll also assume you've already created a new GitLab project. If you haven't, go ahead and do that now.
Setting up your Xcode project
We'll start by creating a new single-view iOS project in Xcode.
Give your project a name and make certain that the Include Unit Tests and Include UI Tests options are enabled for the project. Xcode will create a template test class with some sample tests, which we'll use in this post as the test suite that GitLab CI runs to verify a build. Choose a name for your project and click on Next.
Choose where you'll save your iOS project. If you like, let Xcode create the git repository on your Mac.
A scheme is a collection of settings that specify which targets to build, what build configuration to use, and the executable environment to use when the product specified by the target is launched.
By sharing your scheme, GitLab CI gets context it needs to build and test your project.
To share a scheme in Xcode, choose Product > Scheme > Manage Schemes.
Click on the Close button.
Your Xcode project has been created with two test files; one includes sample unit tests, and the other includes sample UI tests. You can run Product > Test to run these tests, which will build your project, launch the Simulator, install the project on the Simulator device, and run the test suite. You can see the results right in Xcode:
The green checkmarks next to the test functions (both in the file, and in the Test navigator) show that all tests passed. We won't be referring to the Xcode project anymore, so if you like, you can close it.
Next, open Terminal and navigate to the folder you created for your iOS project.
It's convenient to add a standard
.gitignore file. For a Swift project, enter:
$ curl -o .gitignore https://www.gitignore.io/api/swift
For an Objective-C project, enter:
$ curl -o .gitignore https://www.gitignore.io/api/objective-c
curl command conveniently downloads the contents of the page at the given gitignore.io URL into a file named
If Xcode initialized the git repository for you, you'll need to set the origin url to your GitLab project (replaceing
<username> with your GitLab username and
<project> with the project name:
$ git remote add origin firstname.lastname@example.org:<username>/<project>.git
The final step here is to install xcpretty. When Xcode builds and tests your project, xcpretty will transform the output into something more readable for you.
Installing and registering the GitLab Runner
The GitLab Runner is a service that's installed on your Mac, which runs the build and test process that you set up in a configuration file. You can follow the installation instructions for OS X, but we'll need to make some changes to the register the runner step:
$ gitlab-ci-multi-runner register WARNING: Running in user-mode. WARNING: The user-mode requires you to manually start builds processing: WARNING: $ gitlab-runner run WARNING: Use sudo for system-mode: WARNING: $ sudo gitlab-runner...
If you're using self-hosted GitLab, the coordinator URL will be http(s)://url-of-your-gitlab-instance/ci`.
Please enter the gitlab-ci coordinator URL (e.g. https://gitlab.com/ci): https://gitlab.com/ci
The CI token for your project is available on GitLab's Project Settings page, under Advanced Settings. Each project has a unique token.
Please enter the gitlab-ci token for this runner: <CI runner token from Project > Settings > Runner>
register process suggests the name of your Mac as a description for the runner. You can enter something different if you like, or just hit return to continue.
Please enter the gitlab-ci description for this runner: [Your-Mac's-Name.local]:
Enter whatever tags you'd like to further identify this particular runner. It's particularly helpful when you need a particular build environment—for example, iOS 9.2 on Xcode 7.2 on OS X 10.11 could use tags like
osx_10-11. This way, we can filter our build stages in GitLab by toolchain, platform, etc.
Please enter the gitlab-ci tags for this runner (comma separated): ios_9-2, xcode_7-2, osx_10-11
The GitLab Runner will register the runner and give it a unique
Registering runner... succeeded runner=s8Bgtktb
The GitLab Runner has to run
xcodebuild to build and test the project, so we select
shell as the executor:
Please enter the executor: virtualbox, ssh, shell, parallels, docker, docker-ssh: shell Runner registered successfully. Feel free to start it, but if it's running already the config should be automatically reloaded!
Continue with the rest of the Runner installation instructions (
start), per the documentation.
Go to the Runners page in your Project Settings and voilà:
Your GitLab Runner is recognized and (almost) ready to go!
You can verify this by running
$ gitlab-ci-multi-runner verify WARNING: Running in user-mode. WARNING: The user-mode requires you to manually start builds processing: WARNING: $ gitlab-runner run WARNING: Use sudo for system-mode: WARNING: $ sudo gitlab-runner... Veryfing runner... is alive runner=25c780b3
Note that they have the same ID (in this case,
The last thing to do is to configure the build and test settings. To do so, open your text editor and enter the following:
stages: - build build_project: stage: build script: - xcodebuild clean -project ProjectName.xcodeproj -scheme SchemeName | xcpretty - xcodebuild test -project ProjectName.xcodeproj -scheme SchemeName -destination 'platform=iOS Simulator,name=iPhone 6s,OS=9.2' | xcpretty -s tags: - ios_9-2 - xcode_7-2 - osx_10-11
Save this file in your Xcode project folder as
.gitlab-ci.yml, and don't forget the period at the beginning of the file name!
Update: To clarify, the
.gitlab-ci.ymlfile should go in the folder you created for your iOS project, which is also typically where your Xcode project file (
ProjectName.xcodeproj) is found. Thanks to commenter Palo for pointing this out!
Let's go through the file with some detail:
- The file first describes the
stagesavailable to each
job. For simplicity, we have one stage (
build) and one job (
- The file then provides the settings for each
build_projectjob runs two scripts: one to clean the Xcode project, and then another to build and test it. You can probably skip the cleaning script to save time, unless you want to be sure that you're building from a clean state.
tags, add the tags you created when you registered the GitLab Runner.
There are also some things to look out for:
- Make sure to replace all references to
ProjectNamewith the name of your Xcode project; if you're using a different scheme than the default, then make sure you pass in the proper
SchemeNametoo (the default is the same as the
- In the
xcodebuild testcommand, notice the
-destinationoption is set to launch an iPhone 6S image running iOS 9.2 in the Simulator; if you want to run a different device (iPad, for example), you'll need to change this.
- If you're using a workspace rather than a project (e.g., because your app uses Cocoapods), change the
-project ProjectName.xcodeprojoptions to
-workspace WorkspaceName.xcworkspace. There are several options available to customize your build; run
xcodebuild --helpin the Terminal to explore these further.
There's a simple tool for "linting" (i.e., validating) your
.gitlab-ci.yml in GitLab. From your GitLab project page, click on Builds in the sidebar, then in the upper-right corner, click on CI Lint:
Paste the contents of your
.gitlab-ci.yml file into the text box and click on Validate. You should see something like:
Status: syntax is correct
This won't tell you if your project name or the Simulator chosen is correct, so be sure to double-check these settings.
.gitlab-ci.yml file is extremely customizable. You can limit jobs to run on success or failure, or depending on branches or tags, etc.—read through the documentation to get a feeling for just how flexible and powerful it is.
Setting up your GitLab project for CI
Actually, there's really not much to do here! CI is enabled by default on new projects. If your iOS project has some environment variables you want to keep secret, but you want to keep the project public on GitLab, you may want to disable Public builds in Project Settings, under Continous Integration. This will hide the build results from everyone except members of the project.
You may also want to go to Runners under your Project Settings and click Disable shared runners, as they're not needed anyhow—we're using a project-specific runner.
We're now ready to trigger a CI build!
How to trigger builds
To trigger a build, all you have to do is push a commit to GitLab. From the Terminal:
$ git add . $ git commit -m "First commit." [...commit info...] $ git push origin master [...push info...]
If everything worked, and you installed the GitLab Runner on the same machine, you'll notice that Simulator launches, installs your iOS app and launches it, and then goes back to the home screen.
Go to the Builds page of your GitLab project and have a look at the results!
Click on the <span style=color:green>✔︎ success</span> button to see the build output:
Here you'll see the output from all the steps you requested in your
.gitlab-ci.yml file. At the bottom of the log, you should see something like:
All tests Test Suite GitLab-CI-for-iOSTests.xctest started GitLab_CI_for_iOSTests . testExample (0.001 seconds) T testPerformanceExample measured (0.000 seconds) . testPerformanceExample (0.324 seconds) Executed 2 tests, with 0 failures (0 unexpected) in 0.325 (0.328) seconds All tests Test Suite GitLab-CI-for-iOSUITests.xctest started GitLab_CI_for_iOSUITests . testExample (3.587 seconds) Executed 1 test, with 0 failures (0 unexpected) in 3.587 (3.589) seconds Build succeeded.
Now you can go ahead and start writing tests for your code, and every time you push a commit, GitLab will diligently fetch the project, clean it, and then build and test it. If the build fails, you can take action to fix the commit.
Starting and stopping the runner on your Mac
The GitLab Runner includes several convenient commands, which you can list easily:
$ gitlab-ci-multi-runner --help NAME: gitlab-ci-multi-runner - a GitLab Runner USAGE: gitlab-ci-multi-runner [global options] command [command options] [arguments...] VERSION: 1.0.4 (014aa8c) AUTHOR(S): Kamil Trzciński <email@example.com> COMMANDS: archive find and archive files (internal) artifacts upload build artifacts (internal) extract extract files from an archive (internal) exec execute a build locally list List all configured runners run run multi runner service register register a new runner install install service uninstall uninstall service start start service stop stop service restart restart service status get status of a service run-single start single runner unregister unregister specific runner verify verify all registered runners help, h Shows a list of commands or help for one command GLOBAL OPTIONS: --debug debug mode [$DEBUG] --log-level, -l "info" Log level (options: debug, info, warn, error, fatal, panic) --help, -h show help --version, -v print the version
You may want to stop the Runner so that a build isn't immediately triggered by a pushed commit:
$ gitlab-ci-multi-runner stop $ gitlab-ci-multi-runner status gitlab-runner: Service is not running.
In this case, any builds pushed will show up as pending and will be triggered as soon as you restart the Runner:
$ gitlab-ci-multi-runner start $ gitlab-ci-multi-runner status gitlab-runner: Service is running!
Any pending builds in the queue will then be triggered, launching Simulator and running the test suite normally.
Advanced: archiving the project automatically
Let's say that, if we commit to
master, we want GitLab CI to not only build and test the project, but also provide some continuous delivery, where it creates an application archive, and uploads it to GitLab.
We start by modifying our
.gitlab-ci.yml file to add an
archive stage and an
stages: - build - archive build_project: stage: build script: - xcodebuild clean -project ProjectName.xcodeproj -scheme SchemeName | xcpretty - xcodebuild test -project ProjectName.xcodeproj -scheme SchemeName -destination 'platform=iOS Simulator,name=iPhone 6s,OS=9.2' | xcpretty -s tags: - ios_9-2 - xcode_7-2 - osx_10-11 archive_project: stage: archive script: - xcodebuild clean archive -archivePath build/ProjectName -scheme SchemeName - xcodebuild -exportArchive -exportFormat ipa -archivePath "build/ProjectName.xcarchive" -exportPath "build/ProjectName.ipa" -exportProvisioningProfile "ProvisioningProfileName" only: - master artifacts: paths: - build/ProjectName.ipa tags: - ios_9-2 - xcode_7-2 - osx_10-11
archive_project job runs two scripts: the first cleans and archives your Xcode project, and the second builds an
.ipa file; the
only setting means that this job will only run when we commit to master. Notice that it also defines
artifacts; after the
ProjectName.ipa application archive is created, this option uploads it to GitLab, where you can later download it from the Build page.
exportArchive script, make sure you pass in the correct
ProvisioningProfileName. It's possible that the
archive_project job will fail if your developer keys are in the login Keychain, because it's not unlocked in the script. The simplest way to fix this without putting your password in a script is to open Keychain Access on your Mac and drag and drop them to the System Keychain.
Now, when we commit to master, the build will also show us the archive results, along with the option to download or browse our build artifacts!
Other salient points
- This workflow should work for any kind of Xcode project, including tvOS, watchOS, and Mac OS X. Just be sure to specify the appropriate Simulator device in your
- If you want to push a commit but don't want to trigger a CI build, simply add
[ci skip]to your commit message.
- If the user that installed the GitLab runner isn't logged in, the runner won't run. So, if builds seem to be pending for a long time, you may want to check on this!
- If you're working on a team, or if your project is public, you may want to install the GitLab Runner on a dedicated build machine. It can otherwise be very distracting to be using your machine and have Simulator launch unexpectedly to run a test suite.
- The test project used in this particular tutorial is available here, but the Runner is permanently stopped. Note that the project isn't tied to a particular team, so provisioning isn't an issue here; in fact, no provisioning profile is specified. You, however, may need to add some parameters to the build scripts in your
.gitlab-ci.ymlfile if you see provisioning errors in your build output.
About guest author Angelo Stavrow
Angelo is a Quality Engineer and Software Developer living in Montreal, Canada. He believes that open, honest, collaboration is the best path towards building great things and great teams.
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