Continuous integration in iOS for fun and profit

Published in

tajawal

7 min readMar 22, 2018

They say a picture says more than a thousand words.

Looking at the picture above, you see an illustration of my preferred road to setup continuous integration. In this article, I am going to be explaining how to properly setup CI process for your iOS apps, also we will see how to debug common issues that you might face.

Important to know is that you should install Ruby Version Manager (RVM) to make sure that you have consistent ruby version installed on your system and are able to manage multiple installations of Ruby on the same device. Once that is done I will talk about how to install Fastlane: A tool that help us automatinging development and release process for iOS and Android apps. Fastlane handles all tedious tasks like dealing with code signing, beta deployment, App Store deployment, automate screenshots…etc
Once we are done with that, we will take a look into setting up Jenkins, which will be the continuous delivery hub, allowing us to create different jobs for beta and App Store deployment.

So why RVM?

Fastlane is written in Ruby, which means installing it could be as easy as running this command:

sudo gem install fastlane

Using this command to install Fastlane will result in using Apple’s system version of Ruby, and having it placed in the/usr/bin directory. Let me explain why that’s not a good thing.

OS X comes with various open source packages pre-installed. The packages are only updated to their latest versions as part of major OS X Updates and some packages are used elsewhere by other parts of OS X. In general, Apple assumes (and so should you) that everything under/System/Library and /usr/ (except /usr/local/ of course) is part of the operating system, and therefore administered by Apple.
This is why any attempt to remove or modify files in these directories will result in problems along the way. That applies to all open sources packages that come with OS X, including Ruby.

The right approach is having new versions installed in a seperate location, using the RVM.

Note that this will not only help you with having proper setup for Fastlane, but also for any other ruby gems you install.

1. RVM 💎

To check where your Ruby installation is located, run the below command:

which ruby

If you are using the pre-installed Ruby version, it might respond with the below line:

/usr/bin/ruby

INSTALLLATION

Now I will mention simple steps to install RVM but you can always check the installation page of RVM.

Install gpg using Homebrew:

brew install gnupg

2. Install the mpapis public key:

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB

Note: hkp://keys.gnupg.net can sometimes timeout you may want to use different keyserver, for example: hkp://pgp.mit.edu.

3. Install RVM with the latest stable version of Ruby:

\curl -sSL https://get.rvm.io | bash -s stable --ruby

After the installation is completed, close the terminal window and open a new one.

Then run this command:

rvm list

You will see the list of available rubies:

rvm rubies=* ruby-2.4.1 [ x86_64 ]# => — current
# =* — current && default
# * — default

Now it’s time to start using the RVM’s Ruby by running the command:

rvm use ruby-2.4.1

You can verify that you are using RVM’s Ruby by running which ruby. If all is set up correct, you will see a similar output as below:

/Users/mkalatrash/.rvm/rubies/ruby-2.4.1/bin/ruby

That’s it for the first step 🎉.

2. Fastlane 🚀

Next up is installing Fastlane and integrating it in the project.

Run the below command, to install fastlane tools and the necessary dependencies:

gem install fastlane

Once it’s done make sure that fastlane is installed in rvm/gems directory by running:

gem which fastlane

The output of this command should be similar to:

/Users/mkalatrash/.rvm/gems/ruby-2.4.1/gems/fastlane-2.81.0/fastlane/lib/fastlane.rb

Integrating Fastlane into your project 🚀

For our example I created new project named iOSAutomationTutorial.

Navigate to your project’s root folder and run:

 fastlane init

Once you have run the command, a new folder will be created in the project directory named fastlane. Now Fastlane will continue with the setup through couple of possible steps. In our case we will choose the 4th option which is Manual setup.

Continue by pressing Enter until Fastlane is done.

Now we will add new lane to our fastfile in order have it build the iOS project for us, but before that we will need to make sure the project scheme is shared:

Open the project.
Select scheme followed by manage scheme.
Make sure “Shared” is checked.

Let’s proceed. Open fastfile located in./iOSAutomationTutorial/fastlane(I prefer to use Sublime Text) and add the below:

default_platform(:ios)platform :ios do  desc "Build iOS App"    lane :build do      xcodebuild(build_settings: {          "CODE_SIGNING_REQUIRED" => "NO",          "CODE_SIGN_IDENTITY" => ""          })     endend

Save and run this command to make sure your setup is working fine:

bundle exec fastlane build

Please note that I used bundle to run fastlane which is recomended.
In case you don’t have bundler, then you need to install it first by running
gem install bundler.

If everything is fine you should see a success message from Fastlane.

More information on this you can find Fastlane docs.

3. Jenkins 🚘

You have reached the final step in the setup. Now all that’s left is installing Jenkins on your server machine.

The recommended way to install Jenkins is through homebrew:

brew update && brew install jenkins

If you have a fresh version of Mac OS then download the latest version of the JDK from here or get it by running this command :

brew cask install caskroom/versions/java8

From now on start Jenkins by running:

jenkins

Or you could run it as a background service, using the below command:

brew services start jenkins

Now we will have to go through Jenkins initial setup. An admin user has been created and a password is automatically generated (password will be prinited in your terminal).

Go to http://localhost:8080, which is the local address of your Jenkins.

Provide your administrator password and press continue.

Select Install suggested plugins, which will cover all the important plugins.

After installing all plugins, Jenkins will ask you to provide credentials for a new admin user. Just select Continue as admin for now.

Your Jenkins setup is done and ready for it’s first job! 🎉

In order to change the initial password or create a new user go to admin > Configure, Jenkins > Manage Jenkins > Manager Users.

Before creating your first job we will need an extra plugin to get installed. Go to Manage jenkins > Manage Plugins > Available.

Now search and install the RVM plugin, which will help specifiying which ruby version to use. This way we won’t run into situations where Jenkins can’t find fastlane or other ruby gems we use, as I described before.

After you install RVM plugin, restart Jenkins and then on the homepage click on Create new jobs.

Enter job name and select Freestyle project

We will now create a job to build the iOS project.
Proceed by entering the job name and selecting freestyle project, followed by clicking OK (see snapshot above).

Now we clone the project from the public repo using git plugin that comes with Jenkins:

At this point, make sure you have Xcode and command line developer tools installed.

Secondly, check the RVM plugin and mention Ruby version you will use (While writing this it’s 2.4.1).

Third and last is to add an “Execute shell” step as your first build step and call add:

bundle updatebundle exec fastlane build

Specifying Ruby version and adding Execute shell

Click Save and on Build Now. Your job will start executing and the start building. When the build finishes you will see a success message like the one below: