Installing Tomcat

English Hello everyone and welcome back. This is Ahmed again for Eduonix and this is beginning Jenkins section 2 Jenkins installation. In the previous lecture we have seen how we can install Jenkins on a myriad of options, myriad of hosts and platforms. Lets start by our first option here or one of our options which is installing Jenkins as servlet or inside a java container as it is sometimes called. Sometimes it's also called an application server and for this lab we have chosen Tomcat as our applications server because it's lightweight compared to other fully fledged application servers like WebSphere or Weblogic they're going to take a lot of time to install and configure. We just want to demonstrate Jenkins and not the application server itself. So we have chosen Tomcat for those purposes. Again Jenkins needs Java version 7 for a minimum and tomcat version 5 for the minimum. I could have gone through the steps of deploying Java 8 and downloading and installing tomcat. However vagrant has a box that has those components already installed. It can be used to for our Jenkins installation. So let's have a look at our example system. This is my terminal. This is my Mac. And I have already as you can see here I have already installed vagrant on this machine. So I could use it to create my machine that is going to be used for Jenkins. So in your home directory or whatever path you desire. In my case I'm going to use the home directory. I'm going to create a new directory. I'm going to call it a Tomcat. And vagrant actually works on a directory basis. This means that if I am inside this directory then the vagrant command I'm going to use is going to manage all the machines that are running inside this directory. Once I am outside the directory I cannot use vagrant to manage the machines that are inside this directory. I have to be inside the directory to manage the machines that are installed or are open and are running there. Okay so I'm going to create a directory for Tomcat because I want to host a machine that has Tomcat pre installed on this directory. So I want to have a friendly name or a descriptive name. The second step is to choose is to run vagrant init and vagrant init is the command that will create something called a vagrant file. A vagrant file is nothing more text file that i am going to show it to you in a moment. This text file contains all the instructions that vagrant needs to start the machine. It contains instructions like for example network cards. If you want to forward some port we're gonna come to this in a moment. If you want to have another user and the default user which is vagrant. If you want to change the memory or the CPU that is used in a machine in addition to other options even if you want to configure the machine automatically through a configuration management system like ansible or Chef or puppet or salt or even Docker you can do that using the vagrant file. So the vagrant init command is used to create this file and I need to add on I can actually pass in the name of the machine that I want to use. Or in our case the name of the box that I want to use and it's called emessiha. It's a strange name but it is the one that contains the Tomcat installation /ubuntu64-java and i can optionally pass in the box version 1.0.0. Once i click enter as you can see here It has informed me that I have vagrant file created in my directory. If I go inside directory and then this vagrant file I can see that it contains a lot of options. They are all well commented and they are all well explained. As you can see here one of the most important options here that I can configure or i can with is the config.vm Network. This one because this one is the option or the configuration that forwards ports from the machine. The guest machine to the host machine. The vagrant machine here is called guest while the Mac my machine my local machine is called the host because it is hosting this guest, it is hosting this machine on its system. OK so if you want to access any port inside the guest machine you cannot because by default it uses something that is called NAT that is short for network address translation. It is a way of protecting the network ports that are inside that are running inside the guest by preventing any access by preventing any external access to those ports except if you want to explicitly allow this access by forwarding the port internally to the host. In other words if I'm running web server inside the guest machine and this web server is running Of course by default on port 80. If I want to access this port from outside the vagrant host from the vagrant guest I would have to use port 8080 on the local host. So if I want to access this website I will have to go to my browser and navigate to a local host or 127.0.0.1 which is the address of the local host as you already know. Column 8080 and vagrant is going to translate or to forward any traffic that is coming to port 8080 to the guest on port 80 and the other way around. Any traffic that is coming from this guest to the source of the traffic or to the user or the client that is requesting the page it is going to be forwarded in the same channel to the requesting host. So why this is important because we are going to actually forwards the traffic that is coming to port 8080 on our guests because port 8080 is the new full port that Jenkins runs on or Tomcat runs on because tomcat as well runs on that 8080. Both of them actually run on 8080. Whether Jenkins is running as a standalone application or inside tomcat both of them use the 8080 port. So I'm going to forward traffic that is coming at Port 8080 on the host to the same port but on the guest. Why. Because the guest will be running Jenkins or tomcat on Port 8080. I want the user to enter the same port when he or she accesses this application via localhost. I don't want to change the port. I want it to be 8080 as well and that is possible I can forward the port to the same port or I can forward it to a different port. It's up to me so I'm going leave it like this 8080. And the next step is of course if you want to have any other configuration you are free to do so you can as you can see here change the memory you can change. You can even run a shell script that gets run as soon as the machine is up or running. This is called a provisioning the machine. Provisioning is one of the devops terms that are used by devops engineers. So you can for example choose to run a shell script that will install Apache for example when the machine gets started. You can also use as we said any of the configuration managers or providers such as puppet, chef, ansible, salt and docker. Okay so you feel free to change this file whatever however you want. Once done save the file and the next step is issuing vagrant up. And in issue vagrant up vagrant will do one of two things. It will search for the box and the box it refers to the templates by which vagrant pulls the image from and starts deploying it on your machine as a virtual machine or as a vagrant machine. If it finds this box on your system it is going to use it. If you haven't installed this box yet or if you haven't downloaded this box yet it is going to go and fetch that box from its default website which is Atlas.hashicorp.com. And once done once the box is done downloading it's going to use it for this installation as well as subsequent installations. So when I click enter on vagrant up and because I have already downloaded this box before before starting this lab you are going to see that it's gonna import the base box from my file system from my local machine instead of having to go and download it from an external website. And this of course will save a lot of time. So let's wait till the machines are running. Notice here that vagrant is forwarding ports the port that we have already configured 8080 is being forwarded to port 8080 and actually this machine is already is also preconfigured with some other software. It comes pre installed with Apache and also the MySql database server. We don't need those we just need the tomcat installation and now it's up and running. In order to access this machine all what we have to do is just issue vagrant. SSH like this and you are in. This is the machine. This machine already inside already has Tomcat installed. If you want to make sure Let's just clear the screen and we can run system CDL status tomcat. And as you can see here Tomcat is active and running. This means that if I go to a browser like this and use one of those windows that we have already and localhost 8080 if I click enter as you can see here I have an installation of Tomcat. It is Tomcat 9 and as we have said the latest the least version of Tomcat that were needed is 7 so we have version 9. It's already above the minimum requirements. So now we are ready to install Jenkins on our Tomcat server. And that is going to be a starting topic of our next lecture. So until then. See you next.