Continuous integration for Android – a beginners tutorial

Continuous integration (CI) is a software development practice that allows developers to integrate their code into a shared repository multiple times a day. This process helps to catch and fix any issues early in the development process.

When it comes to a native Android app, continuous integration typically involves the following steps:

1. Setting up a version control system (such as Git) to store and manage the code for the app.
   A version control system (VCS) is a tool that helps developers to keep track of changes made to their code over time. One of the most popular VCS is Git, which is a distributed version control system. In order to set up a version control system for an Android app, the first step is to install Git on your local machine by downloading it from the official website.After that, you need to create a new repository on a Git hosting service such as GitHub or GitLab. This repository will store all the code for your app. In your local machine, navigate to the root folder of your Android project and open a terminal window.

   Then, you need to initialize a new Git repository by running the command “git init”. After that, you connect your local repository to the remote repository you created on the hosting service by running the command “git remote add origin [remote repository URL]”. This will allow you to push and pull code between your local machine and the remote repository. Once the connection is established, you can add all the files in your project to the repository by running the command “git add .”, and then commit the files to the repository by running the command “git commit -m “initial commit”.

   Finally, you can push the files to the remote repository by running the command “git push origin master”. With a version control system in place, developers can easily track changes made to their code over time, collaborate with other developers, and easily roll back to a previous version of the code if necessary. This is an essential step for any software development project and specially for android apps.

2. Creating a build script (such as Gradle) that automates the process of building and testing the app.
   Creating a build script is an important step in automating the process of building and testing an Android app. A build script is a set of instructions that tell the computer how to build and test the app. One of the most popular build scripts for Android apps is Gradle.Gradle is an open-source build automation system that is designed to automate the process of building, testing, and deploying software. It is used to build and manage the dependencies of an Android app. With Gradle, developers can define the dependencies that their app needs, and Gradle will automatically download and include those dependencies in the app. This helps to ensure that all developers are working with the same versions of the dependencies.

   In order to create a Gradle build script, you need to first install Gradle on your local machine by downloading it from the official website. Once Gradle is installed, you can create a new build.gradle file in the root folder of your Android project. This file contains the instructions that tell Gradle how to build and test the app.

   In the build.gradle file, you can define the dependencies that your app needs and specify any other settings that are necessary for building and testing the app. For example, you can specify the version of the Android SDK that you are using and the version of the build tools that you are using.

   Once the build script is set up, developers can run it by running the command “gradle build” in the terminal. This will build the app and run any tests that are specified in the script. With a build script in place, developers can automate the process of building and testing their app, which helps to catch and fix issues early in the development process.

3. Setting up a CI server (such as Jenkins or Travis CI) that is connected to the version control system.
   A CI (Continuous Integration) server is a tool that automates the process of building, testing, and deploying software. It helps developers to catch and fix issues early in the development process. There are many different CI servers available, such as Jenkins and Travis CI, that can be used for an Android app.When setting up a CI server for an Android app, the first step is to choose a server that meets your needs. Jenkins and Travis CI are both popular options, but you should check their documentation and compare the features to select the one that fits your requirements.

   Once you have selected a CI server, you need to install it on your local machine or on a dedicated server. After the installation, you need to connect the CI server to your version control system. This allows the CI server to automatically build and test the app every time new code is pushed to the repository.

   To connect the CI server to your version control system, you need to create a new job on the CI server and configure it to use the version control system. You need to specify the repository URL and any necessary credentials. Additionally, you need to configure the job to use the build script (such as Gradle) to build and test the app.

   Once the CI server is set up and connected to the version control system, it will automatically build and test the app every time new code is pushed to the repository. This helps to catch and fix issues early in the development process, and also helps to ensure that the app is stable and ready for release.

4. Configuring the CI server to automatically build and test the app every time new code is pushed to the repository.
   To configure the CI server to automatically build and test the app, you need to set up a job on the CI server. A job is a set of instructions that tell the CI server what to do. In this case, the job will be to build and test the app.Once the job is set up, you need to configure it to run automatically every time new code is pushed to the repository. This is typically done by setting up a build trigger. A build trigger is an instruction that tells the CI server to start building and testing the app whenever a certain event occurs. For example, you can set up a build trigger to start the job whenever new code is pushed to the repository.

   Additionally, you need to configure the job to use the build script (such as Gradle) to build and test the app. This will ensure that the app is built and tested according to the instructions specified in the build script.

   Once the CI server is set up and configured to automatically build and test the app, it will continuously monitor the repository for changes. Every time new code is pushed to the repository, the CI server will automatically build and test the app. This helps to catch and fix issues early in the development process and ensures that the app is stable and ready for release.

5. Integrating the app with other tools such as code analysis, code coverage, and test automation.
   It is an important step in the continuous integration process. These tools help to ensure that the app is of high quality and free of bugs.Code analysis tools are used to check the code for potential issues such as coding standards violations, and to detect errors that could lead to bugs. Some popular code analysis tools for Android apps include Lint and FindBugs. These tools can be integrated with the build process and can automatically check the code for issues before the app is built.

   Code coverage tools are used to measure how much of the app’s code is being tested. They help to identify areas of the app that are not being adequately tested. Some popular code coverage tools for Android apps include Jacoco and SonarQube. These tools can be integrated with the build process and can automatically measure code coverage before the app is built.

   Test automation tools are used to automate the process of testing the app. They allow developers to write tests that can be run automatically every time the app is built. Some popular test automation tools for Android apps include Espresso and Robotium. These tools can be integrated with the build process and can automatically run tests before the app is built.

   Integrating the app with these tools will help you to ensure that the app is of high quality and free of bugs. Additionally, these tools can be configured to send notifications to the development team in case of a failure, which helps to catch and fix issues early in the development process.

6. Generating the app’s artifacts (APK files) and deploying them to the play store.
   Artifacts are the files that are created during the build process, such as the APK files that are used to distribute the app. Deploying the app to the app stores allows users to download and install the app on their devices.To generate the app’s artifacts, you need to configure the build process to create an APK file. An APK file is an executable file that contains all the necessary files for the app to run on an Android device. Once the APK file is generated, it can be deployed to the app stores.

   To deploy the app to the app stores, you need to create an account with the app store. The most popular app store for Android apps is the Google Play Store. Once you have an account, you can upload the APK file to the app store and make it available for users to download and install.

   Additionally, you can configure the CI server to automatically deploy the app to the app stores. This can be done by creating a post-build action on the CI server that runs a script to deploy the app to the app stores. This allows developers to automatically deploy the app to the app stores every time new code is pushed to the repository.

   Generating the app’s artifacts and deploying them to playstore allows users to download and install the app on their devices. Additionally, it can be automated with the help of CI server which helps to save time and effort. This is an essential step in the continuous integration process as it allows developers to quickly release new versions of the app to users.

7. Setting up notifications to be sent to the development team in case of a build failure.
   It helps the team to quickly identify and fix issues that occur during the build process.To set up notifications, you need to configure the CI server to send a message or an email to the development team in case of a build failure. This can be done by creating a post-build action on the CI server that runs a script to send a notification.

   There are various ways to send notifications, for example, you can set up an email notification that sends an email to the development team whenever a build fails. You can also set up a notification through a messaging tool such as Slack, which sends a message to a specific channel or group when a build fails.

   Additionally, you can configure the CI server to send notifications to specific individuals or groups based on the type of failure. For example, you can set up a notification to send an email to the project manager if a build fails, and another notification to send a message to the development team if a test fails.

   Setting up notifications helps the development team to quickly identify and fix issues that occur during the build process. This can help to minimize the impact of the issues on the project and ensure that the app is stable and ready for release.

8. Continuously monitoring the builds and making the necessary adjustments to improve the app’s stability and performance.
   To continuously monitor the builds, you need to track the build results over time. This can be done by setting up a dashboard on the CI server that displays the build results. The dashboard should include information such as the number of builds, the number of successful builds, and the number of failed builds.Additionally, you need to track the results of code analysis, code coverage, and test automation tools. This can be done by integrating these tools with the CI server and displaying the results on the dashboard.

   Once the builds and results are tracked, you can analyze the data and identify any issues that may be impacting the app’s stability and performance. For example, if the number of failed builds is high, you may need to investigate the cause and make adjustments to the build process.

   Once the issues are identified, you can make the necessary adjustments to improve the app’s stability and performance. This can include changes to the build script, changes to the code, or changes to the testing process.

   Continuously monitoring the builds and making the necessary adjustments to improve the app’s stability and performance is an important step in the continuous integration process. It helps to ensure that the app is of high quality and free of bugs, which will result in a better user experience.

    

With continuous integration, developers can detect and fix issues early in the development process. This helps to ensure that the app is stable and ready for release. It also allows developers to work on different features simultaneously without having to worry about integration issues.