How does the process from pushing to a branch to deploying an image on a stand technically occur?

After pushing to a branch, a CI/CD pipeline usually triggers, automating the build and deployment process. Technically, it works as follows:

1. Pipeline trigger: The CI system (e.g., Jenkins, GitLab CI, GitHub Actions) monitors pushes to a specific branch.
2. Project build: The Java application is built, including compilation, running tests, and static analysis.
3. Creating a Docker image: After a successful build, a Docker image with the application is created and tagged (e.g., by commit number or version).
4. Publishing the image: The image is pushed to a Docker Registry (Docker Hub, Nexus, Artifactory).
5. Deploying to the environment: The deployment system (e.g., Kubernetes, Ansible, Helm) pulls the new image and updates the service on the environment.

An example of a simplified Jenkinsfile:

pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                sh './gradlew build'
            }
        }
        stage('Docker Build & Push') {
            steps {
                script {
                    def image = "myapp:${env.GIT_COMMIT}"
                    sh "docker build -t ${image} ."
                    sh "docker push ${image}"
                }
            }
        }
        stage('Deploy') {
            steps {
                sh 'kubectl set image deployment/myapp myapp=myapp:${env.GIT_COMMIT} -n staging'
            }
        }
    }
}