Install OpenJDK 21

Download the JDK binary:

wget https://mirrors.huaweicloud.com/openjdk/21/openjdk-21_linux-x64_bin.tar.gz

Extract and relocate to /usr/local:

sudo tar -xzf openjdk-21_linux-x64_bin.tar.gz -C /usr/local/
ls /usr/local/jdk-21/

Update system-wide environment variables by editing /etc/profile:

export JAVA_HOME=/usr/local/jdk-21
export PATH=$JAVA_HOME/bin:$PATH

Apply chenges and verify installation:

source /etc/profile
java --version

Configure Apache Maven 3.9.10

Download and extract Maven:

wget https://dlcdn.apache.org/maven/maven-3/3.9.10/binaries/apache-maven-3.9.10-bin.tar.gz
sudo tar -xzf apache-maven-3.9.10-bin.tar.gz -C /usr/local/

Add Maven to your environment in /etc/profile:

export MAVEN_HOME=/usr/local/apache-maven-3.9.10
export PATH=$PATH:$MAVEN_HOME/bin

Customize Maven settings by editing $MAVEN_HOME/conf/settings.xml:

<localRepository>/usr/local/mvn-repo</localRepository>

<mirror>
  <id>aliyun-central</id>
  <url>https://maven.aliyun.com/repository/public</url>
  <mirrorOf>central</mirrorOf>
</mirror>

Reload profile and test:

source /etc/profile
mvn --version

Compile and Install Git 2.28 from Source

Remove any outdated version:

sudo yum remove git -y

Install build dependencies:

sudo yum install -y curl-devel expat-devel gettext-devel openssl-devel zlib-devel gcc perl-ExtUtils-MakeMaker

Download and compile Git:

wget https://www.kernel.org/pub/software/scm/git/git-2.28.0.tar.xz
tar -xf git-2.28.0.tar.xz
cd git-2.28.0
make prefix=/usr/local all
sudo make prefix=/usr/local install

Update PATH and verify:

echo 'export PATH="/usr/local/bin:$PATH"' >> /etc/profile
source /etc/profile
git --version

Deploy Jenkins via Docker

Pull the official Jenkins image:

docker pull jenkins/jenkins:lts

Create persistent volume directory:

sudo mkdir -p /var/jenkins_data
sudo chmod 777 /var/jenkins_data

Launch container with port mapping and volume mounts:

docker run -d \
  --name ci-server \
  -p 8080:8080 \
  -p 50000:50000 \
  -v /var/jenkins_data:/var/jenkins_home \
  -v /etc/localtime:/etc/localtime:ro \
  jenkins/jenkins:lts

Verify container status and view startup logs:

docker ps
docker logs ci-server

Access Jenkins at http://<server-ip>:8080 after retrieving the initial admin password from logs.