Implementation of CI/CD in Java application(Linux) Using Shell and Docker Executor on GitLab
Last Updated :
23 Jul, 2025
There are many executors available to implement CI/CD with GitLab Runner. However, Shell and Docker are more popular among them, and we can easily configure a repository with these runners. These runners can be chosen based on the requirements and availability of the resources. This article mainly focuses on Shell and Docker executors of Java Linux application and code is written in bash script. The application can build and test using a bash script.
Shell Executor: Shell Executor is a very simple executor which helps to build the solution locally on the machine, where GitLab Runner is installed. In this case, GitLab Runner is installed on Linux Machine, so need to install the required software in the same system.
Docker Executor: It is a powerful tool that includes much software and it can be accessed by image. The advantage of this executor is that, we do not need to install any software manually, everything will be taken care of through docker and the required image will be downloaded from the docker hub. However, the disadvantage is that this communication is blocked in some organizations due to security purposes. So, If this is the case Shell Executor is the best alternative.
Implementation of Java on Shell Executor
Requirements
These are the basic software that needs to install on a Linux machine. However, it can be changed based on the compilation script and need to download other software if needed.
Software | Description |
---|
Git | This is the first requirement, to commit the changes on GitLab. It is a version control software that tracks the changing set of files |
JDK | Need to install a specific version of JDK on the machine which you have targeted, to build the jar file. For example, OpenJDK-8 |
Apache Ant | This is a tool that helps to build processes and generate the jar file of the project while running this file. It contains more information about the project and add this information inside the jar. |
Path Configuration
After successful installation, you need to set the path of this installed software in the machine, if it is not set. Run the below command on the machine.
Variable / File | Path |
---|
Git | Set the path of Git in the Linux machine, if it already not set. Can check with which git export Git = /usr/bin/git |
JAVA | export JAVA=/usr/bin/java Can check with which java |
Apache Ant | export ANT=/usr/bin/ant Can check with which ant |
Permission | Give Permission to build.xml before it runs: chmod -R 777 * |
build.xml | It will build the project, and generate the jar based on containing information |
.gitlab-ci.yml | This file should be inside the root directory of the project which contains all the CI/CD configuration including software and script path. Here, you can mention how this repository should run. Before adding this file to the root directory, should check it is a valid yml file or not. |
GitLab Runner Set Up
Follow the below steps to download and configure the GitLab Runner.
1. Download GitLab Runner on Linux Machine
sudo curl -L --output /usr/local/bin/gitlab-runner https://gitlab-runner-downloads.s3.amazonaws.com/latest/binaries/gitlab-runner-linux-amd64
2. Give it permissions to execute using the following command:
sudo chmod +x /usr/local/bin/gitlab-runner
3. Create a GitLab CI use the following command:
sudo useradd --comment 'GitLab Runner' --create-home gitlab-runner --shell /bin/bash
4. Install and run as a service using the following command:
sudo gitlab-runner install --user=gitlab-runner --working-directory=/home/gitlab-runner
5. Start GitLab Runner using the following command:
sudo gitlab-runner start
6. Stop the GitLab Runner before registering the repository using the following command:
sudo gitlab-runner stop
7. Once GitLab Runner is successfully stopped enter the following command in the terminal for repository registration.
sudo gitlab-runner register
8. When you do repository registration with GitLab Runner, the below questions have to answer.
- Enter your GitLab instance URL: It can be different with each organization and the format will be like http://gitlab.example.com
- Path: Go to GitLab Account → Select repository which you want to register with runner → Settings → CI/CD → Expand Runner
- Enter the gitlab-ci token for this runner: It will be a unique token of each project which will need while registration and it can be found
- Path: Go to GitLab Account → Select repository which you want to register with runner → Settings → CI/CD → Expand Runner
- Enter the gitlab-ci description for this runner: Put Runner name(any name), which will help you to remember that which runner' is running
- Enter the gitlab-ci tags for this runner: It is optional if you want to start GitLab runner when a specific tag is available in yml file.
- Enter the executor: There will be a list of several executors, and type shell(as GitLab Runner will run our system)
9. After successful registration, start the GitLab Runner using the following command
sudo gitlab-runner start
To verify that GitLab Runner has registered the respective repository and the runner has been started. Go to GitLab Account → Select repository which you want to register with runner → Settings → CI/CD → Expand Runner, There will be a green color circle will be available, and displaying message will be Runners activated for this project.
Note: If the circle is gray, it means the runner has not started and starts again.
Linux GitLab Runner Commands
Command | Description |
---|
sudo gitlab-runner register | Register the project with GitLab Runner |
sudo gitlab-runner register | Start the runner |
sudo gitlab-runner stop | Stop the runner |
sudo gitlab-runner status | To know the status of gitlab-runner |
sudo gitlab-runner unregister --name test-runner | Unregister the Runner of a project and replace the test-runner with your runner name and this name can be found inside the config.toml file (where your gitlab-runner ) available. |
sudo gitlab-runner unregister --url http://gitlab.example.com/ --token t0k3n | Remove Runner by URL and token |
sudo gitlab-runner unregister --all-runners | Unregister All Runners |
sudo gitlab-runner restart | This command stops and then starts the GitLab Runner service |
sudo gitlab-runner uninstall | This command stops and uninstalls the GitLab Runner from being run as a service |
sudo gitlab-runner exec | To see a list of available executors, run |
sudo gitlab-runner --help | Check a recent list of commands by executing |
sudo gitlab-runner run --help | Can see the name of the environment variable |
sudo gitlab-runner --debug | To run a command in debug mode |
sudo gitlab-runner exec shell | To see a list of all available options for the shell executor, run |
.gitlab-ci.yml_shell Executor: Below is the content of .gitlab-ci.yml on shell executor mode. However, change it if needed based on requirements.
stages:
- build
- execute
build:
stage: build
script:
- ant -f build.xml
artifacts:
paths:
- abc.jar
execute:
stage: execute
script:
- pwd
- cd scripts
- chmod -R 777 *
- pwd
- ./run.sh
Implementation of Java on Docker Executor
There is no need to install any software manually, everything will be taken from the docker container. However, you can install the required software inputting the name in yml file and also can export the path. To run the GitLab runner on docker executor mode, Go to GitLab Runner Set-Up(above), and select docker instead of shell.
.gitlab-ci.yml_ Docker Executor: Below are the content of .gitlab-ci.yml on docker executor mode. However, change it if needed.
image: ubuntu:latest
stages:
- build
- execute
before_script:
- echo "Before script section"
- apt-get update && apt-get -y install openjdk-8-jdk && apt-get -y install ant
build:
stage: build
script:
- ant -f build.xml
artifacts:
paths:
- abc.jar
execute:
stage: execute
script:
- pwd
- cd scripts
- chmod -R 777 *
- pwd
- ./runtest.sh
Similar Reads
Java Tutorial Java is a high-level, object-oriented programming language used to build web apps, mobile applications, and enterprise software systems. It is known for its Write Once, Run Anywhere capability, which means code written in Java can run on any device that supports the Java Virtual Machine (JVM).Java s
10 min read
Basics
Introduction to JavaJava is a high-level, object-oriented programming language developed by Sun Microsystems in 1995. It is platform-independent, which means we can write code once and run it anywhere using the Java Virtual Machine (JVM). Java is mostly used for building desktop applications, web applications, Android
4 min read
Java Programming BasicsJava is one of the most popular and widely used programming language and platform. A platform is an environment that helps to develop and run programs written in any programming language. Java is fast, reliable and secure. From desktop to web applications, scientific supercomputers to gaming console
4 min read
Java MethodsJava Methods are blocks of code that perform a specific task. A method allows us to reuse code, improving both efficiency and organization. All methods in Java must belong to a class. Methods are similar to functions and expose the behavior of objects.Example: Java program to demonstrate how to crea
7 min read
Access Modifiers in JavaIn Java, access modifiers are essential tools that define how the members of a class, like variables, methods, and even the class itself, can be accessed from other parts of our program. They are an important part of building secure and modular code when designing large applications. In this article
6 min read
Arrays in JavaIn Java, an array is an important linear data structure that allows us to store multiple values of the same type. Arrays in Java are objects, like all other objects in Java, arrays implicitly inherit from the java.lang.Object class. This allows you to invoke methods defined in Object (such as toStri
9 min read
Java StringsIn Java, a String is the type of object that can store a sequence of characters enclosed by double quotes and every character is stored in 16 bits, i.e., using UTF 16-bit encoding. A string acts the same as an array of characters. Java provides a robust and flexible API for handling strings, allowin
8 min read
Regular Expressions in JavaIn Java, Regular Expressions or Regex (in short) in Java is an API for defining String patterns that can be used for searching, manipulating, and editing a string in Java. Email validation and passwords are a few areas of strings where Regex is widely used to define the constraints. Regular Expressi
7 min read
OOPs & Interfaces
Classes and Objects in JavaIn Java, classes and objects are basic concepts of Object Oriented Programming (OOPs) that are used to represent real-world concepts and entities. A class is a template to create objects having similar properties and behavior, or in other words, we can say that a class is a blueprint for objects.An
10 min read
Java ConstructorsIn Java, constructors play an important role in object creation. A constructor is a special block of code that is called when an object is created. Its main job is to initialize the object, to set up its internal state, or to assign default values to its attributes. This process happens automaticall
10 min read
Java OOP(Object Oriented Programming) ConceptsBefore Object-Oriented Programming (OOPs), most programs used a procedural approach, where the focus was on writing step-by-step functions. This made it harder to manage and reuse code in large applications.To overcome these limitations, Object-Oriented Programming was introduced. Java is built arou
10 min read
Java PackagesPackages in Java are a mechanism that encapsulates a group of classes, sub-packages and interfaces. Packages are used for: Prevent naming conflicts by allowing classes with the same name to exist in different packages, like college.staff.cse.Employee and college.staff.ee.Employee.They make it easier
8 min read
Java InterfaceAn Interface in Java programming language is defined as an abstract type used to specify the behaviour of a class. An interface in Java is a blueprint of a behaviour. A Java interface contains static constants and abstract methods. Key Properties of Interface:The interface in Java is a mechanism to
11 min read
Collections
Exception Handling
Java Exception HandlingException handling in Java is an effective mechanism for managing runtime errors to ensure the application's regular flow is maintained. Some Common examples of exceptions include ClassNotFoundException, IOException, SQLException, RemoteException, etc. By handling these exceptions, Java enables deve
8 min read
Java Try Catch BlockA try-catch block in Java is a mechanism to handle exceptions. This make sure that the application continues to run even if an error occurs. The code inside the try block is executed, and if any exception occurs, it is then caught by the catch block.Example: Here, we are going to handle the Arithmet
4 min read
Java final, finally and finalizeIn Java, the final, finally, and finalize keywords play an important role in exception handling. The main difference between final, finally, and finalize is listed below:final: The final is the keyword that can be used for immutability and restrictions in variables, methods, and classes.finally: The
4 min read
Chained Exceptions in JavaChained Exceptions in Java allow associating one exception with another, i.e. one exception describes the cause of another exception. For example, consider a situation in which a method throws an ArithmeticException because of an attempt to divide by zero.But the root cause of the error was an I/O f
3 min read
Null Pointer Exception in JavaA NullPointerException in Java is a RuntimeException. It occurs when a program attempts to use an object reference that has the null value. In Java, "null" is a special value that can be assigned to object references to indicate the absence of a value.Reasons for Null Pointer ExceptionA NullPointerE
5 min read
Exception Handling with Method Overriding in JavaIn Java, an exception is an unwanted or unexpected event that occurs during a program's execution, i.e., at runtime, and disrupts the normal flow of the programâs instructions. Exception handling in Java handles runtime errors and helps maintain the program's normal flow by using constructs like try
5 min read
Java Advanced
Java Multithreading TutorialThreads are the backbone of multithreading. We are living in the real world which in itself is caught on the web surrounded by lots of applications. With the advancement in technologies, we cannot achieve the speed required to run them simultaneously unless we introduce the concept of multi-tasking
15+ min read
Synchronization in JavaIn multithreading, synchronization is important to make sure multiple threads safely work on shared resources. Without synchronization, data can become inconsistent or corrupted if multiple threads access and modify shared variables at the same time. In Java, it is a mechanism that ensures that only
10 min read
File Handling in JavaIn Java, with the help of File Class, we can work with files. This File Class is inside the java.io package. The File class can be used to create an object of the class and then specifying the name of the file.Why File Handling is Required?File Handling is an integral part of any programming languag
6 min read
Java Method ReferencesIn Java, a method is a collection of statements that perform some specific task and return the result to the caller. A method reference is the shorthand syntax for a lambda expression that contains just one method call. In general, one does not have to pass arguments to method references.Why Use Met
9 min read
Java 8 Stream TutorialJava 8 introduces Stream, which is a new abstract layer, and some new additional packages in Java 8 called java.util.stream. A Stream is a sequence of components that can be processed sequentially. These packages include classes, interfaces, and enum to allow functional-style operations on the eleme
15+ min read
Java NetworkingWhen computing devices such as laptops, desktops, servers, smartphones, and tablets and an eternally-expanding arrangement of IoT gadgets such as cameras, door locks, doorbells, refrigerators, audio/visual systems, thermostats, and various sensors are sharing information and data with each other is
15+ min read
JDBC TutorialJDBC stands for Java Database Connectivity. JDBC is a Java API or tool used in Java applications to interact with the database. It is a specification from Sun Microsystems that provides APIs for Java applications to communicate with different databases. Interfaces and Classes for JDBC API comes unde
12 min read
Java Memory ManagementJava memory management is the process by which the Java Virtual Machine (JVM) automatically handles the allocation and deallocation of memory. It uses a garbage collector to reclaim memory by removing unused objects, eliminating the need for manual memory managementJVM Memory StructureJVM defines va
4 min read
Garbage Collection in JavaGarbage collection in Java is an automatic memory management process that helps Java programs run efficiently. Java programs compile to bytecode that can be run on a Java Virtual Machine (JVM). When Java programs run on the JVM, objects in the heap are created, which is a portion of memory dedicated
7 min read
Memory Leaks in JavaIn programming, a memory leak happens when a program keeps using memory but does not give it back when it's done. It simply means the program slowly uses more and more memory, which can make things slow and even stop working. Working of Memory Management in JavaJava has automatic garbage collection,
3 min read
Practice Java
Java Interview Questions and AnswersJava is one of the most popular programming languages in the world, known for its versatility, portability, and wide range of applications. Java is the most used language in top companies such as Uber, Airbnb, Google, Netflix, Instagram, Spotify, Amazon, and many more because of its features and per
15+ min read
Java Programs - Java Programming ExamplesIn this article, we will learn and prepare for Interviews using Java Programming Examples. From basic Java programs like the Fibonacci series, Prime numbers, Factorial numbers, and Palindrome numbers to advanced Java programs.Java is one of the most popular programming languages today because of its
8 min read
Java Exercises - Basic to Advanced Java Practice Programs with SolutionsLooking for Java exercises to test your Java skills, then explore our topic-wise Java practice exercises? Here you will get 25 plus practice problems that help to upscale your Java skills. As we know Java is one of the most popular languages because of its robust and secure nature. But, programmers
7 min read
Java Quiz | Level Up Your Java SkillsThe best way to scale up your coding skills is by practicing the exercise. And if you are a Java programmer looking to test your Java skills and knowledge? Then, this Java quiz is designed to challenge your understanding of Java programming concepts and assess your excellence in the language. In thi
1 min read
Top 50 Java Project Ideas For Beginners and Advanced [Update 2025]Java is one of the most popular and versatile programming languages, known for its reliability, security, and platform independence. Developed by James Gosling in 1982, Java is widely used across industries like big data, mobile development, finance, and e-commerce.Building Java projects is an excel
15+ min read