Why do we need Tomcat for Jenkins?

Tomcat is a Servlet Java Container to run web applications. Additionally, Java and setting the path environment variables are pre-requisite to install the Tomcat server. Moreover, after downloading and running the tomcat server, we need to put jenkins.

Why is Tomcat needed?

Essentially it’s an open-source Java servlet and Java Server Page container that lets developers implement an array of enterprise Java applications. Tomcat also runs a HTTP web server environment in which Java code can run.

How does Tomcat integrate with Jenkins?

Jenkins – Tomcat Setup

1. Step 1: Verifying Java Installation. To verify Java installation, open the console and execute the following java command.
2. Step 2: Verifying Java Installation.
3. Step 3: Download Tomcat.
4. Step 4: Jenkins and Tomcat Setup.

What is the difference between Tomcat and Jenkins?

Jenkins allows you to do Continuous Integration and development, for example whenever you push any changes to github it will build that project and deploy to your server. Tomcat on the other hand is Application Server that executes Java Servlets and renders the Web Page.

Can Jenkins and Tomcat same port?

In Tomcat, the default HTTP Connector port is 8080. If Jenkins was using 8080 by default, then the HTTP Connector port is probably what you changed to 8081 in /etc/sysconfig/jenkins .

What is the JDK requirement for Jenkins installation?

Pre-Requisites

• Hardware Requirements: You need a minimum of 1 GB+ of RAM and 50 GB+ of drive space to install Jenkins.
• Software Requirements: Java 8, either a Java Runtime Environment (JRE) or a Java Development Kit (JDK) is fine.

What is Tomcat process?

Normally Tomcat is running in one process and the web servers runs in another; this however requires the web server to communicate using some IPC mechanism such as TCP/IP. When Tomcat is running inside the web server process, requests for servlet execution are passed using JNI (and performance improves).

What is Tomcat and how it works?

Tomcat receives a request from a client through one of its connectors. If it has not, Tomcat compiles the servlet into Java bytecode, which is executable by the JVM, and creates an instance of the servlet. Tomcat initializes the servlet by calling its init method.

How does Tomcat deploy war with Jenkins?

To recap, here is a summary of the steps required to perform a Jenkins Tomcat WAR file deployment:

1. Add a user with WAR deployment rights to the tomcat-users.
2. Add the Deploy to container Jenkins Tomcat plugin.
3. Create a Jenkins build job with a Deploy to container post-build action.
4. Run the Jenkins build job.

Can Jenkins run without Tomcat?

Jenkins is typically run as a standalone application in its own process with the built-in Java servlet container/application server (Jetty). Jenkins can also be run as a servlet in different Java servlet containers such as Apache Tomcat or GlassFish.

What is plugin in Jenkins?

Plugins are the primary means of enhancing the functionality of a Jenkins environment to suit organization- or user-specific needs. There are over a thousand different plugins which can be installed on a Jenkins controller and to integrate various build tools, cloud providers, analysis tools, and much more.

Does Jenkins need JDK or JRE?

Generally, Jenkins allows ANY version of JRE/JDK to be invoked during the build. It includes: Execution of Java commands from CLI. Installation and execution of build steps using JDK managed by JDK tool installers.

How to install Jenkins on Apache Tomcat server?

Navigate to Jenkins Download page and download LTS – Jenkins WAR file as shown below:- Copy jenkins.war file and go to extracted Apache tomcat folder. There you will find a folder named “webapps”. Copied jenkins.war file. Navigate to bin folder of Apache Tomcat Server.

Is Tomcat ready to receive deployments?

Now we will advance to the next level which is making Tomcat ready to receive deployments and enabling TEXT based and GUI based management interface. All the tomcat application servers come with the manager application by default. If you look at the webapps directory of your downloaded tomcat server. You can see it.

How to start Tomcat server on other port?

Note – To start tomcat server on other port, go to conf folder in Apache tomcat folder. You will find a server.xml file. Change port to whatever you want. This is optional step. To start tomcat server, click on “startup” window batch file. It will open command prompt and start server. Notice that it will deploy war file as well.

Where is the manager application in Tomcat server?

All the tomcat application servers come with the manager application by default. If you look at the webapps directory of your downloaded tomcat server. You can see it. At the first time, you may not be able to access it cause the manager application needs some security elements to be configured prior to being accessed.