Ansible real-time project - Installing and configure Tomcat 10

 Hey DevOps or DevSecOps or SRE Guys!!

What's up? in the automation journey one more wonderful learning here! 

In this post we will be implementing all our Ansible modules one after other to build a complete solution for Java based Application server installation and running using Ansible playbook.

At present Tomcat latest version is 10.0.27 so I've used same 

Pre-requisites: 

• To install Apache Tomcat there is separate JDK/JRE compatibility we need to validate before we proceed
• Create a dedicated user account as 'tomcat' with shell as bash to manage Tomcat application server
• Create a separate directory for tomcat server to be installed

Execution of multiple tasks in the Playbook will be as follows:

• Download the Tomcat software from Apache Tomcat 10.0.27.tar.gz
• Uncompressing the tomcat tar.gz file
• Change the file permissions and ownership
• Cleanup after unarchive the tar.gz file
• Start the Tomcat server
• Have a task to stop the Tomcat server

---
- name: Installation and setup Apache Tomcat 10
  hosts: "{{ targets | default('localhost') }}"
  become: yes
  gather_facts: no
  tasks:
  
    - name: Install openjdk
      yum:
        name: java-1.8.0-openjdk
        state: present
      tags: install_openjdk

    - name: Create user as tomcat
      user:
        name: tomcat
        state: present
        home: /home/tomcat
        shell: /bin/bash
      tags: pre-install

    - name: Create a directory - /opt/tomcat
      file:
        path: /opt/tomcat
        state: directory
        mode: 0755
        owner: tomcat
        group: tomcat
      tags: pre-install

    - name: Download tomcat - apache-tomcat-10.0.27.tar.gz
      get_url:
        url:  https://dlcdn.apache.org/tomcat/tomcat-10/v10.0.27/bin/apache-tomcat-10.0.27.tar.gz
        dest: /opt/tomcat
      tags: pre-install 

    - name: Extract tomcat inside directory and set ownership, permissions
      unarchive:
        src: /opt/tomcat/apache-tomcat-10.0.27.tar.gz
        dest: /opt/tomcat
        extra_opts: [--strip-components=1]
        remote_src: yes
        owner: tomcat
        group: tomcat
        mode: "u+rwx,g+rx,o=rx"
      tags: tomcat-install

    - name: Remove gz file apache-tomcat-10.0.27.tar.gz
      file:
        path: /opt/tomcat/apache-tomcat-10.0.27.tar.gz
        state: absent
      tags: post-install

    - name: Start the Tomcat server
      become_user: tomcat
      shell:
        cmd: nohup ./startup.sh
        chdir: /opt/tomcat/bin
      tags: start-tomcat

    - name: Stop the Tomcat server
      become_user: tomcat
      shell:
        cmd: nohup ./shutdown.sh
        chdir: /opt/tomcat/bin
      tags: stop-tomcat, never
      

You can run the playbook in multiple ways

1. Use the target as webserver group to install Tomcat only on them.   

ansible-playbook tomcat-solutoin.yaml -e targets=webservers

2. Use the tags to stop the Tomcat servers.   

ansible-playbook tomcat-solutoin.yaml -t stop-tomcat -e targets=webservers

3. Use the tags to start the Tomcat server.   

ansible-playbook tomcat-solutoin.yaml -e targets=webservers

Finding & Terminating a process on remote VM

The play can be having two tasks where you need to find the running process by process name or command used to run it. If there is any error ignore them. Try to catch the result into a variable to pass it to next task.
Example - find process which is started with java
Second task is to terminating a process which is identified in the first task. Here we can use 'shell' module where we can use 'kill' running process.

---
 - name: Find Java process and Terminate
   hosts: "{{ targets | default ('localhost') }}"
   gather_facts: false

   tasks:
     - name: Get the running Java process
       shell: "ps -ef|grep tomcat |grep -v grep | awk {'print $2'}"
       register: JavaProcessID

     - name: Print Java Process
       debug:
         msg: "{{ JavaProcessID.stdout }}"

     - name: Terminating Java Process
       become: yes
       become_user: tomcat
       shell: "kill -9 {{ JavaProcessID.stdout }}"

Execute the playbook as follows:

ansible-playbook find_killtomcat.yaml -e targets=webservers

The output Image:

Using shell module to find and kill tomcat process