What is Gradle?
Gradle is an open-source build automation tool flexible enough to build almost any type of software. Gradle makes few assumptions about what you’re trying to build or how to build it. This makes Gradle particularly flexible.
Design
Gradle bases its design on the following fundamentals:High performance
Gradle avoids unnecessary work by only running tasks that need to do work because inputs or outputs have changed. Gradle uses various caches to reuse outputs from previous builds. With a shared build cache, you can even reuse outputs from other machines.JVM foundation
Gradle runs on the JVM. This is a bonus for users familiar with Java, since build logic can use the standard Java APIs. It also makes it easy to run Gradle on different platforms.Conventions
Gradle makes common types of projects easy to build through conventions. Plugins set sensible defaults to keep build scripts minimal. But these conventions don’t limit you: you can configure settings, add your own tasks, and make many other customizations in your builds.Extensibility
Most builds have special requirements that require custom build logic. You can readily extend Gradle to provide your own build logic with custom tasks and plugins. See Android builds for an example: they add many new build concepts such as flavors and build types.IDE support
Several major IDEs provide interaction with Gradle builds, including Android Studio, IntelliJ IDEA, Eclipse, VSCode, and NetBeans. Gradle can also generate the solution files required to load a project into Visual Studio.Insight
Build Scan™ provides extensive information about a build that you can use to identify issues. You can use Build Scans to identify problems with a build’s performance and even share them for debugging help.
How to executing Gradle builds on Jenkins?
Building Gradle projects doesn’t stop with the developer’s machine. Continuous Integration (CI) has been a long-established practice for running a build for every single change committed to version control to tighten the feedback loop.
In this guide, we’ll discuss how to configure Jenkins for a typical Gradle project.
What you’ll need
- A text editor
- A command prompt
- The Java Development Kit (JDK), version 1.7 or higher
- A Jenkins installation (setup steps explained in this post)
Setup a typical project
As example, this guide is going to focus on a Java-based project. More specifically, a Gradle plugin written in Java and tested with Spek. First, we’ll get the project set up on your local machine before covering the same steps on CI.
Just follow these steps:
Clone the Gradle Site Plugin repository
$ git clone https://github.com/gradle/gradle-site-plugin.git Cloning into 'gradle-site-plugin'... $ cd gradle-site-plugin
Build the project
As a developer of a Java project, you’ll typical want to compile the source code, run the tests and assemble the JAR artifact. That’s no different for Gradle plugins. The following command achieves exactly that:
$ ./gradlew build BUILD SUCCESSFUL 14 actionable tasks: 14 executed
The project provides the Gradle Wrapper as part of the repository. It is a recommended practice for any Gradle project as it enables your project to built on CI without having to install the Gradle runtime.
Build scan integration
The sample project is equipped with support for generating build scans. Running the build with the command line option --scan renders a link in the console.
$ ./gradlew build --scan Publishing build scan... https://gradle.com/s/7mtynxxmesdio
The following section will describe how to build the project with the help of Jenkins.
Setup Jenkins
Jenkins is one of the most prominent players in the field. In the course of this section, you’ll learn how to set up Jenkins, configure a job to pull the source code from GitHub and run the Gradle build.
Install and start Jenkins
On the Jenkins website you can pick from a variety of distributions. This post uses the runnable WAR file. A simple Java command brings up the Jenkins server.
$ wget https://mirrors.jenkins.io/war-stable/latest/jenkins.war $ java -jar jenkins.war
In the browser, navigate to localhost with port 8080 to render the Jenkins dashboard. You will be asked to set up an new administration user and which plugins to install.
Installation of plugins
Confirm to install the recommended plugins when starting Jenkins for the first time. Under “Manage Jenkins > Manage Plugins” ensure that you have the following two plugins installed.
- Git plugin
- Gradle plugin
Next, we can set up the job for building the project.
Create a Jenkins job
Setting up a new Gradle job can be achieved with just a couple of clicks. From the left navigation bar select “New Item > Freestyle project”. Enter a new name for the project. We’ll pick “gradle-site-plugin” for the project.
Select the radio button “Git” in the section “Source Code Management”. Enter the URL of the GitHub repository: https://github.com/gradle/gradle-site-plugin.git.
Furthermore, create a “Build step” in the section “Build” by selecting “Invoke Gradle build script”. As mentioned before, we’ll want to use the Wrapper to execute the build. In the “Tasks” input box enter the build and use the “Switches” --scan -s to generate a build scan and render a stack trace in case of a build failure.
Execute the job
Save the configuration of job and execute an initial build by triggering the “Build Now” button. The build should finish successfully and render a “Gradle Build Scan” icon that brings you directly to the build scan for the given build.
There are various options to trigger Jenkins builds continuously: from polling the repository periodically, to building on a set schedule, or via callback URL.
Gradle Fabricating Q&A
Q1. To execute the hello task in the build file, type ___ on the command line.
Answer:- Gradle hello or gradle –q hello
Q2. Consider the following gradle build script:
task a{
ext.myProperty = “Hello”
}
task b{
doLast {
println a.myProperty
println c.myProperty
}}
task c(dependsOn: b){
ext.myProperty = “Hey”
println “Hi”}
If the task gradle -q c is run, what is the output?
Answer:- hi Hello hey
Q3. In gradle, a disabled task is labelled as _________.
Answer:- Disabled
Q4. Multiline comments in Gradle build files are included using _____ .
Answer:- /* Multi line */
Q5. Gradle tasks can also be created and extended dynamically at runtime.
Answer:- True
Q6. Gradle build scripts use a combination of declarative and imperative statements.
Answer:- True
Q7. Which plugins are configured while integrating gradle with Jenkins?
Answer:- Gradle plugin and plugin of repository used
Q8. Which of the following statement is true about Jenkins?
Answer:- All the options
Q9. Jobs are the unit of execution in Jenkins.
Answer: –True
Q10. In Jenkins, a build job performs _______.
Answer:- All the options
Q11.
Q11. Which are the two types of plugins in gradle?
Answer:- Script and binary
Q12. Which of the following statements are true?
Answer: – Ant or maven script can be migrated to gradle build script
Q13. When gradle plugins are applied to a project, it is possible to _____________.
Answer:- All the options
Q14. How to check gradle version?
Answer:- Gradle -v or gradle -version
Q15. How to check gradle version?
Answer:- All the options
Q16. The two build files generated by android studio are in ________________.
Answer:- Root folder of project and app directory
Q17. The war plugin enables the default JAR archive generation of the Java plugin.
Answer:- True
Q18. Running Gradle builds with the Daemon executes the build quickly.
Answer: – True
Q19. In gradle to specify, which projects belong to the build, and which file is used? Answer- Settings.gradle
Q20. Gradle build scripts are written in _________.
Answer:- Groovy or Kotlin
Q21. In Gradle , the java plugin searches for java test source code in the directory ___________.
Answer:- src/test/java
Q22. Gradle supports multiple project templates called archetypes ________.
Answer:- False
Q23. Gradle requires a Java JDK or JRE and Groovy to be installed.
Answer: – False
Q24. Gradle requires a Java JDK or JRE and Groovy to be installed.
Answer:- True
Q25. The wrapper plugin can be auto-applied to the root project of the current build without modifying the build.gradle file.
Answer:- False
Q26. Gradle tasks can also be created and extended dynamically at runtime.
Answer:- True
Q27. Gradle is an imperative build tool.
Answer:-False
Q28. Which task is executed to use Gradle Build Init plugin?
Answer: – init
Q29. Which method is used to attach a predicate to a skipping task?
Answer:- OnlyIf()
Q30. Which of the following is Gradle’s in-built task?
Answer:- All the options
Q31. Lifecycle tasks typically have task actions.
Answer:- False
Q32. Java Plugin is a binary plugin
Answer: – True
Q33. The first line added in the build script to make the Android plug-in available for a Gradle build is ____________. apply plugin
Answer:- ‘com.android.application’
Q34. Gradle is a _______ based build tool.
Answer:- JVM
Q35. Gradle Build Init plugin is an automatically applied plugin.
Answer:- True
Q36. Applying the Application plugin also implicitly applies the Java plugin.
Answer:- True
Q37. hich of the following is Gradle’s in-built task?
Answer- All the options mentioned
