How to Set Up a Secure Linux Server with JDK, Tomcat, and Docker

1. Enable Security Group

1.1 Open security group

In the cloud console, enable the security group and allow inbound traffic.

1.2 Obtain public IP and reset root password

Find the server’s public IP address, reset the root password, and reboot if required.

2. Install Baota (BT) Panel

2.1 Download and run installer

yum install -y wget && wget -O install.sh http://download.bt.cn/install/install_6.0.sh && sh install.sh

Answer “y” to all prompts.

2.2 Open required ports

Configure the security group to expose ports needed by subsequent services (e.g., 80, 8080, 22, 2375, etc.).

3. Install JDK, Tomcat and configure firewall

3.1 Remove existing OpenJDK packages (if any)

rpm -qa | grep java
yum -y remove java-1.7.0-openjdk-1.7.0.141-2.6.10.5.el7.x86_64
yum -y remove java-1.8.0-openjdk-1.8.0.131-11.b12.el7.x86_64

3.2 Install Oracle JDK 11

rpm -ivh jdk-11.0.8_linux-x64_bin.rpm
java -version

3.3 Install Tomcat 9

tar -zxvf apache-tomcat-9.0.37.tar.gz
cd apache-tomcat-9.0.37
./bin/startup.sh

3.4 Firewall configuration

# Check firewalld status
systemctl status firewalld

# Start / restart / stop firewalld
service firewalld start
service firewalld restart
service firewalld stop

# List current rules
firewall-cmd --list-all
firewall-cmd --list-ports

# Open a port permanently (example: 80/tcp)
firewall-cmd --zone=public --add-port=80/tcp --permanent
systemctl restart firewalld.service

Parameters: --zone defines the rule scope, --add-port=PORT/PROTOCOL adds the port, --permanent makes the rule survive reboots.

4. Install Docker CE via YUM

4.1 Prepare environment

yum -y install gcc gcc-c++

4.2 Remove older Docker packages

yum remove docker \
 docker-client \
 docker-client-latest \
 docker-common \
 docker-latest \
 docker-latest-logrotate \
 docker-logrotate \
 docker-engine

4.3 Install required utilities

sudo yum install -y yum-utils

4.4 Add Alibaba Cloud mirror for Docker CE

yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

4.5 Update YUM cache and install Docker CE

yum makecache fast
yum -y install docker-ce docker-ce-cli containerd.io

4.6 Start Docker and verify

systemctl start docker
ps -ef | grep docker

Reference Docker CE installation guide for CentOS: https://docs.docker.com/engine/install/centos/