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Java Role

Overview

The java role installs Java (JDK or JRE) on target systems. This is a prerequisite for running Apache Cassandra, Elasticsearch, and AxonOps components.

Requirements

  • Ansible 2.9 or higher
  • Target system running a supported Linux distribution (RHEL, CentOS, Ubuntu, Debian)
  • Internet access or local package repositories

Role Variables

Basic Configuration

Variable Default Description
java_use_zulu false Use Azul Zulu Java instead of OpenJDK (Debian-based systems only)
java_install_epel false Install EPEL repository before installing Java (RHEL-based systems)
java_pkg - Specific Java package to install (defined in playbook)

Supported Java Distributions

OpenJDK (Default)

The role installs OpenJDK by default, which is available on all supported platforms.

Azul Zulu (Optional)

Azul Zulu OpenJDK builds can be installed on Debian-based systems by setting java_use_zulu: true.

Dependencies

None

Example Playbooks

Basic Java 11 Installation

- name: Install Java 11
  hosts: cassandra
  become: true
  vars:
    java_pkg: java-11-openjdk-headless

  roles:
    - role: axonops.axonops.java

Java 17 Installation (for Cassandra 5.x)

- name: Install Java 17
  hosts: cassandra
  become: true
  vars:
    java_pkg: java-17-openjdk-headless

  roles:
    - role: axonops.axonops.java

Using Azul Zulu Java (Debian/Ubuntu)

- name: Install Zulu Java 11
  hosts: cassandra
  become: true
  vars:
    java_use_zulu: true
    java_pkg: zulu-11

  roles:
    - role: axonops.axonops.java

With EPEL Repository (RHEL/CentOS)

- name: Install Java with EPEL
  hosts: cassandra
  become: true
  vars:
    java_install_epel: true
    java_pkg: java-11-openjdk-headless

  roles:
    - role: axonops.axonops.java

Complete Stack with Java

- name: Deploy Cassandra Stack with Java
  hosts: cassandra
  become: true
  vars:
    java_pkg: java-11-openjdk-headless
    axon_java_agent: "axon-cassandra4.1-agent"
    cassandra_version: 4.1.3

  roles:
    - role: axonops.axonops.java
      tags: java

    - role: axonops.axonops.agent
      tags: agent

    - role: axonops.axonops.cassandra
      tags: cassandra

Java Version Selection Guide

For Cassandra

Cassandra Version Recommended Java Version Package Name (RHEL/CentOS) Package Name (Debian/Ubuntu)
3.11.x Java 8 java-1.8.0-openjdk-headless openjdk-8-jre-headless
4.0.x - 4.1.x Java 11 java-11-openjdk-headless openjdk-11-jre-headless
5.0.x+ Java 17 java-17-openjdk-headless openjdk-17-jre-headless

For Elasticsearch

Elasticsearch Version Recommended Java Version
6.x Java 11
7.x Java 11 or 17
8.x Java 17

For AxonOps Server

Component Recommended Java Version
AxonOps Server Java 17
AxonOps Dashboard Not required (Node.js application)

Platform-Specific Examples

RHEL/CentOS/Rocky Linux

- name: Install Java on RHEL
  hosts: rhel_servers
  become: true
  vars:
    java_pkg: java-11-openjdk-headless

  roles:
    - role: axonops.axonops.java

Ubuntu/Debian

- name: Install Java on Ubuntu
  hosts: ubuntu_servers
  become: true
  vars:
    java_pkg: openjdk-11-jre-headless

  roles:
    - role: axonops.axonops.java

Amazon Linux 2

- name: Install Java on Amazon Linux 2
  hosts: amazon_linux
  become: true
  vars:
    java_pkg: java-11-amazon-corretto-headless

  roles:
    - role: axonops.axonops.java

Advanced Configuration

Multiple Java Versions

If you need multiple Java versions, you can use alternatives:

- name: Install and Configure Java Alternatives
  hosts: servers
  become: true
  vars:
    java_pkg: java-17-openjdk-headless

  roles:
    - role: axonops.axonops.java

  post_tasks:
    - name: Set Java 17 as default
      community.general.alternatives:
        name: java
        path: /usr/lib/jvm/java-17-openjdk-amd64/bin/java

Custom JAVA_HOME

- name: Install Java and Set JAVA_HOME
  hosts: servers
  become: true
  vars:
    java_pkg: java-11-openjdk-headless

  roles:
    - role: axonops.axonops.java

  post_tasks:
    - name: Set JAVA_HOME in environment
      ansible.builtin.lineinfile:
        path: /etc/environment
        regexp: '^JAVA_HOME='
        line: 'JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64'

Tags

  • java: Apply all Java installation tasks

Notes

  • Headless Packages: Use -headless packages (e.g., java-11-openjdk-headless) for server installations to avoid installing unnecessary GUI components
  • Package Names: Package names vary between distributions. Check your distribution's package repository for exact names
  • Cross-Platform Support: The role uses the generic package module for improved compatibility across different Linux distributions (RHEL, Debian, Ubuntu, etc.)
  • JAVA_HOME: Most modern installations automatically set JAVA_HOME, but verify if your application requires it
  • Updates: The role installs the latest available version of the specified Java package. Use package pinning if you need a specific minor version
  • Zulu Java: Only available on Debian-based systems through this role

Verification

After installation, verify Java is installed correctly:

java -version

Expected output (for Java 11):

openjdk version "11.0.x" 2023-xx-xx
OpenJDK Runtime Environment (build 11.0.x+x)
OpenJDK 64-Bit Server VM (build 11.0.x+x, mixed mode, sharing)

Troubleshooting

Issue: Package not found

Solution: Ensure the package name is correct for your distribution. Use the platform's package manager to search:

# RHEL/CentOS
yum search openjdk

# Ubuntu/Debian
apt-cache search openjdk

Issue: Multiple Java versions conflict

Solution: Use the alternatives command to manage multiple Java installations:

# RHEL/CentOS
alternatives --config java

# Ubuntu/Debian
update-alternatives --config java

License

See the main collection LICENSE file.

Author

AxonOps Limited