Introduction to RHCE

0:00Hey friends and welcome to the Red Hat Certified Engineer course here on CBT N

0:05uggets.

0:05So what I want to do to begin is to first discuss the general exam objectives

0:11pretty

0:11much what should we actually be tackling within this particular course and

0:15discuss the format

0:16of the course as well as who this course actually should be for.

0:20So with that said let's dive in and look at some of the details.

0:24Now the very first thing to state about the RHC examination is that if you want

0:29to be

0:29eligible and achieve this particular certification you must first have a valid

0:35and current RHCSA

0:37certification.

0:38So if you've not quite yet got your Red Hat Certified System Admin

0:42certification then

0:43fear not we do actually have the RHCSA examination course here on CBT Nuggets

0:48also.

0:49So once you've got that box ticked and you are a valid RHCSA Certified Engineer

0:55you

0:55are therefore eligible to set this particular course. Now important to

0:59understand the RHCE

1:01certification is a performance based exam. There are no written questions, only

1:06written

1:07tasks that you have to perform on a virtual machine.

1:11So the question is what type of tasks should you be expected to know.

1:14Now really traditionally in older iterations of this particular exam you could

1:19expect to

1:19see very advanced Linux admin topics.

1:22However in the new modern version of the examination the actual tasks which you

1:27are asked to perform

1:28are really not that advanced. It is very much the type of content that you

1:33would expect

1:33to see in the RHCSA certification. The difference here in the RHCE exam is that

1:40we are performing

1:40all of these types of tasks that we would do in this particular exam.

1:44But now we are being asked to do those tasks via automation using Red Hat Ans

1:49ible Engine.

1:50So whilst the RHCSA examination might ask you to configure new users on the

1:54system the

1:55RHCE exam will ask you to do the same type of thing this time using Ansible.

2:01Now if we go into the actual objectives here we get a little bit more detail

2:04about what

2:05should actually be studying. Here are the actual tasks that we are expected to

2:08understand.

2:09Notice these are very very similar to what we see in RHCSA. Configuring local

2:15storage,

2:15managing users, basic security, configuring file systems, that type of thing.

2:20But doing

2:20it with this understanding of automation. So we are going to be looking at all

2:23of these

2:24components of Ansible. Things like the inventory, how we can use modules, what

2:28variables are,

2:28how to use loops and conditional statements, that type of thing. We are going

2:32to learn

2:32how we can use rows within Ansible and leverage something known as Ansible

2:36Galaxy. And how

2:37we can set up what is known as the Ansible control node which is basically the

2:41device

2:42on the system that is running Ansible that is performing the Ansible automation

2:46. And

2:47we are going to learn how we can perform those tasks on these managed nodes. So

2:51very important

2:51we will get to see how we can actually use SSH keys for passwordless

2:55authentication,

2:56how we can elevate a privileges on these managed devices that type of thing. We

3:00will talk about

3:00something known as Ansible Navigator, we will talk about creating plays and

3:04playbooks.

3:04As well as a whole bunch of other details including how we can also templatise

3:08configuration

3:09files and protect secret data using a utility known as Ansible Vault. So we are

3:15going to

3:15have a lot of fun within this course. However the very first thing that we are

3:18going to

3:18have to do is to begin building out our lab environment and that begins by

3:22getting a

3:23copy of Red Hat Enterprise Linux.

0:00So friends, one of the very first things that we have to do is we have to get a

0:04hold of

0:04Red Hat Enterprise Linux.

0:07This is the Linux distribution that we're going to be using in order to install

0:11Ansible.

0:11So with that said, let's just dive in.

0:13Now the first thing to say with respect to Red Hat Enterprise Linux is that you

0:18can actually

0:18run this and say for example a cloud environment, or if you so wish you could

0:22run this as a bare

0:24metal installation, pretty much meaning that you could just install it on your

0:28regular hardware,

0:29your laptop, your PC, whatever it may be, and run it just as a regular OS but

0:33that is not

0:35the way that I'm going to recommend that you begin your lab process.

0:38Instead, I'm going to suggest that you make use of virtual machines.

0:42Now perhaps you happen to have some type of software on your computer already,

0:45maybe you're

0:46using something like say VirtualBox.

0:48And if you are, feel free to use that virtualization solution.

0:52In my case though, my personal favorite and the software that I'm going to

0:56recommend you

0:57use is VMware.

0:58So in this particular video, we're going to go through the installation of

1:02getting VMware

1:03available to us.

1:04And then we're going to see how we can actually get a working copy of Red Hat

1:08Enterprise Linux

1:09in order to perform our labbing.

1:11So let's do with the first part of the problem and talk about VMware.

1:15Now the first thing to say is if you happen to be using a Windows machine as

1:19your host

1:19computer, what you should actually search for is VMware Workstation Player.

1:24And if we click on this link right here, notice this is the platform for

1:28running virtual machines

1:30on a Windows or Linux PC.

1:31So once again, even if your host machine happens to be a Linux machine and you

1:35want

1:35to run virtualization software on that machine, then just like with Windows,

1:39you would download

1:40VMware Workstation Player.

1:41Now notice it says you can buy a commercial license.

1:44We don't have to worry about that right here if we just scroll on down.

1:48We can actually try the player for free if we so wish.

1:50This is for non-commercial purposes for your own labbing, that type of thing.

1:54So if you're on Windows, click this link.

1:56If you happen to have a Linux machine as your host machine, you be click this

1:59one instead.

2:00Now in my case, I happen to be using a Mac.

2:02So we have to download VMware Fusion.

2:05So in this case here, we click this link.

2:08Notice it says here that VMware Fusion 13 allows support for Intel or Apple

2:13Silicon,

2:14meaning that if you happen to have an older MacBook with an Intel processor,

2:17you can use

2:18this solution.

2:19Or if you happen to have one of these M1 or M2 MacBooks, the new ones, you can

2:23all

2:24also use VMware Fusion 13.

2:26So in this case here, what I'm going to do, given that I have an M1 MacBook, I

2:30'm going

2:31to click Register for a Personal Use License.

2:33Now it takes us to this page here, VMware Fusion Personal Use License.

2:38If you already have a VMware account, you can just select "I have an account."

2:42If you haven't got that account set up, you first want to create that account

2:45very, very

2:46important.

2:47So all you would do is click this link here.

2:49And what you're going to have to do is to provide some information about

2:52yourself, such

2:53as your email address.

2:54Now just be aware, you can't just put in some dummy email, make sure it is a

2:58real email,

2:59because you're going to have to click a verification link within that email in

3:03order to activate

3:03that account.

3:04So really make sure you can access that email when it pops in.

3:07Then if you scroll on down, you can give your name, your address, job title,

3:10that type

3:10of thing.

3:11Fill out the capture and agree to the terms.

3:13And once you have done that, you will get an email in your inbox and you can

3:16click the

3:17link to verify your account.

3:19Going back to this particular page, you can now select "I have an account."

3:22So let's click this link here.

3:24And all you would do would be to enter that email registered with this account

3:27and pop

3:28in your subsequent password.

3:29So I will just log into mine right now.

3:31Perfect.

3:32Now I've logged in if I just scroll on down.

3:34Now it takes me to my license information.

3:36Now over here, this is where the license key happens to be now, because I don't

3:40want to

3:41share my license with absolutely everyone that's watching this video.

3:44I have just obscured this.

3:46But once you have registered, you will have your own license key.

3:49So all you want to do is to copy that particular key.

3:51Once you have done that, we can now go and click "Manually Download."

3:55And then simply save the download.

3:58And when the download completes, just double click.

4:01Run through all the prompts in the installation wizard and when you are asked,

4:04simply supply

4:05and copy in your own personal license key.

4:08And once you've done that, you will be presented with an interface quite like

4:11this.

4:12There on the left hand side, I've got a whole bunch of virtual machines that I

4:15have created

4:15prior to this course.

4:17If you have a brand new installation, you will not expect to see these down the

4:19left

4:20hand side, don't worry about it.

4:22We're going to create our own Red Hat Enterprise Linux from scratch using this

4:26VMware software.

4:27So now we have access to our VMware virtualization solution.

4:30What we now want to do is to get our hands on a Red Hat Enterprise Linux image

4:34in order

4:34to create that real machine.

4:36So with that said, let's do it.

4:38So in order to get this ISO image, we need to create a Red Hat account.

4:42The first place I'm going to go to is to developers.retat.

4:46So let's click this link right here.

4:48Now in the top right, if I just click log in, what I can do is pass in my Red

4:52Hat account

4:53details right here.

4:55However, if you do not already have that Red Hat account, you would just go

4:58down to

4:59the bottom here and register for a Red Hat account.

5:01So let's just click this link here and you will have to provide some basic

5:05login information

5:06such as your login ID.

5:08So choose a username, give it a password, fill in the personal information,

5:12your first

5:13name, last name, email that type of thing.

5:15Then accept the terms and choose create my accounts.

5:18Now once you actually have a valid Red Hat account, what I'm going to do is

5:22search for

5:23Red Hat Enterprise Linux downloads.

5:25So if you click this link right here.

5:27Now this part is important if you happen to have a regular Windows machine or

5:31an older

5:32MacBook, basically if you happen to have an Intel processor, you can just

5:36select download

5:37rail at no cost right here.

5:39In my case though, because I'm using an M1 MacBook, similarly if you happen to

5:43be using

5:43an M2 MacBook, the newer one, anything Apple Silicon, you're going to have to

5:48get a very

5:48specific version of rail and that is the ARM version, the ARM architecture.

5:53As such, we are going to select more ways to try.

5:56So depending on what you have at home, choose whatever one is appropriate.

5:59In my case here, I'm going to click this link.

6:01So if I just scroll on down right here, the one I want to get is Red Hat

6:05Enterprise Linux

6:07ISO for servers and workstations.

6:10So notice in my case here, I can choose the ARM 64 button, in fact you can also

6:14choose

6:15the regular Intel version if you so want from this page here too.

6:18Now when I click this particular link, if you aren't already logged in, it's

6:22going to

6:22prompt me to login.

6:23This is why it is very important that we have that Red Hat account created.

6:27So click the page, once you've logged in, you'll be presented with a download.

6:32In my case here, I will just choose save and now I'm going to be downloading

6:36Red Hat Enterprise

6:37Linux with the ARM architecture.

6:39So now whilst that download, we will soon have access to Red Hat Enterprise

6:43Linux as well

6:44as our virtualization solution in VMware, what we now want to do is to begin

6:48setting

6:48up our lab environments.

0:00So friends, now that we have access to Red Hat Enterprise Linux, as well as our

0:04virtualization

0:05software, what we want to do is to create three different virtual machines.

0:10Now in the case here, we're going to have one particular virtual machine which

0:14is going

0:14to act as our Ansible Control node.

0:17Pretty much this is going to be the machine that is responsible for managing

0:21all other

0:21machines.

0:22Don't worry about the terminology too much, we'll talk about an in an upcoming

0:26video.

0:26So this is going to be the machine that is responsible for doing all the

0:30automation.

0:30And quite simply Ansible is just software that we're going to install on a Red

0:34Hat Enterprise

0:35Linux machine.

0:36So once again, the first VM is going to be a Rail based and quite honestly, the

0:40next

0:41two machines, machines two and three are also going to be Rail based.

0:46Now just a point of note with respect to using Ansible, the machines that Ans

0:50ible manage

0:50do not all have to be Red Hat Enterprise Linux.

0:53They could for example be Ubuntu, they could be Rocky Linux, whatever it may be

0:58.

0:58The reason why we're using two more additions of Rail has quite simply on the

1:02examination,

1:03you can expect to be managing and dealing with Rail systems.

1:06So it just makes sense to have an entire lab environment all working with Rail.

1:11So like I say, we'll have three different Rail machines, the fourth Rail

1:14machine we

1:14will install Ansible.

1:16In this case here, I'm going to recommend that you install a graphical user

1:19interface

1:20based Rail machine.

1:22This makes things easier to operate.

1:23Now with respect to the machines that are going to be managed by Ansible, if

1:27you happen

1:27to be struggling for resources, then you could get away with just using a

1:31minimal install.

1:33This pretty much means that you're just going to get a basic command line

1:36interface, no

1:36nice graphics, no web browser, that type of thing.

1:39But honestly, it's going to be more than enough to practice working with Ans

1:42ible.

1:43Now in my case, the two other additional machines right here, I am also going

1:47to install them

1:48with a graphical user interface.

1:50The reason why I'm doing that is because I have plenty of resources on my

1:53personal computer

1:55and for the purposes of recording, visually for you at home watching, it just

1:58makes it

1:59nice that if you happen to be looking at a graphical user interface.

2:01But like I say, if you're struggling for resources by all means you can do that

2:05minimal

2:06install for those two.

2:07So let's first walk through the creation of our first machine here, which is

2:11going to

2:11have Ansible installed on it.

2:13So I will pull up my VMware.

2:16Depending if you happen to have a Windows based installation, the interface

2:19might look

2:19a little bit different, but ultimately the configurations are going to be the

2:23same.

2:24The first thing we want to do is to create a new virtual machine.

2:26So I will go to file here and then choose new.

2:29In the case here, I'm going to install from a disk or image.

2:31This is going to be the real image that we just downloaded in the previous

2:35video.

2:35Let's click continue.

2:36So in my case here, I will just choose the real image and then select continue.

2:41So right now we have some default settings as it transpires by default, I'm

2:45using 2Gig

2:46of RAM and 20Gig of hardware space that is going to be plenty fine for me.

2:51So if you so wish you can just choose finish.

2:53But if for example, if you happen to have more resource to despair, no harm in

2:57choosing

2:57customized settings, let's just give the device a name, which is called this

3:01rail control

3:02click save and then you can go into process as a memory.

3:05If you so wish you can crank the memory up to whatever you need.

3:08Allocate more processes that type of thing if you so wish but the default

3:11should suffice.

3:13So with that now done, I will just click play and then I'm just going to arrow

3:16up to actually

3:17install red hat enterprise Linux and just hit enter.

3:20Now just give it some time to boot up and load.

3:22Now the very first time we're going to have to do is to choose your own

3:25language.

3:26In my case here, I'm going to be selecting English and English United Kingdom,

3:30choose

3:31whatever is appropriate for you and then choose continue.

3:34Now the first thing I'm going to do is to choose the installation destination.

3:37Let's click this link here and then I'm going to select this 20 gig hard drive

3:41that I have

3:42cut out for this particular virtual machine.

3:44Once I have that highlighted, I'm going to click again to make sure I see a

3:48tick.

3:48There we go.

3:49And in the case here, I'm not going to worry about data encryption or storage

3:52configuration.

3:53I will leave that automatic and leave the others unchecked.

3:56Let me now just select done.

3:58So with that now done, it says automatic partition and selected.

4:01That's a good sign.

4:02The next one I'm going to go to is network and host name.

4:05So all I want to do is to make sure this ethernet connection is toggled on

4:08right now.

4:09It's on.

4:10If it was off, it would be gray.

4:11In this case here, I want to make sure it is blue.

4:14Once that is done, I will now select done.

4:16Then I'm going to go to software selection.

4:19In the case here, this is going to be my Ansible control mode.

4:22I'm going to recommend you select server with GUI to get that graphical user

4:26interface.

4:27With respect to the other installations, when you're making machine two and

4:30three, if you

4:30so wish, feel free to choose minimal install.

4:33I would select the graphical installation.

4:35So let's choose done.

4:36The next thing I'm going to do is to go down to root passwords.

4:39Let me just give a very bad password or password one, which is absolutely not

4:44secure.

4:45But nevertheless, just for lab and environments, let's just keep it simple.

4:47So again, I will say password one and then I will select done.

4:51Okay.

4:52So now we see the root password is set and then I will go down to user creation

4:56.

4:56Let's click this here and let's just give this a name.

4:59I'll just call this nugget user and I will also make this user and

5:02administrative.

5:03So we can use the pseudo commands and again, just to keep things all simple, I

5:07will just

5:07choose the password or password one.

5:09Like I say, never ever do this in a real live environment.

5:12That's just because it's a lab and any virtual machine.

5:15In the case here, though, I will click done.

5:16It gives me the warning.

5:17Let's click done again to accept it.

5:19And now what I want to do is I want to choose begin installation.

5:23So just give this some time to begin installing all the necessary information.

5:26And most it does that.

5:27I will just temporarily pause the video.

5:29Perfect. Everything has now installed.

5:31What I will now select is reboot system and give it a moment to just reboots.

5:35Okay.

5:36So now we are presented with a login page.

5:38Let's click on our nugget user and I'll type in password one.

5:41Now the first thing it's going to say is do we want to take the tour in this

5:44case here.

5:45I'm just going to select no thanks.

5:47Now notice up the very top here, it says please register your system to receive

5:51software

5:52updates.

5:53If you want to download external packages, easiest way to simply get this done

5:57is to well

5:58register the system.

5:59So let's do that.

6:00So the first thing I will do here is just click X and I'm going to go to my

6:04terminal.

6:05Now you can probably tell that the text is very, very small.

6:08What I want to do is to customize things.

6:10So I'll go to this option here and then go down to preferences.

6:13I will then go to unnamed and then I'll click custom fonts.

6:17And then all I'm going to do is to bump up the font size.

6:21Then I will just choose colors.

6:22I will uncheck this box and then I can select my own color theme.

6:26So in this case here, I will just make the background black and I'll make the

6:29text.

6:30Let's say a red color since it is red at now.

6:32This is certainly not necessary, but just to make things a little bit easier to

6:36follow.

6:36I'm just going to rename the actual computer itself.

6:39So I will just say siddle hostname cTL set hyphen hostname and I will just call

6:45the device

6:46red box.

6:47Now I'll type in my admin password, which is going to be password one.

6:50Now right now the name has not changed.

6:52But if I happen to close the terminal, go back up to activities, open up a

6:56brand new

6:56one.

6:57Notice the name has now changed now with respect to registration.

7:01We're only going to concern ourselves with registering the device that is going

7:05to be

7:05running Ansible, which in my case here is this particular machine.

7:09So what I'm going to do is say sudo subscription manager and then the word

7:13register.

7:14Now I'll have to type in my admin password, which is password one.

7:17And now what I'm going to have to do is to provide my red hat enterprise Linux

7:21details.

7:22Remember we created our accounts.

7:23So all I will do is type in my email associated with my red hat account, which

7:26in my case

7:26here is IPV zero.

7:28If I enter, what I'm now going to have to do is to provide the password that is

7:33associated

7:34with my red hat account.

7:35So this is not the password one that I created on this machine.

7:38It's the actual password that we created when we signed up with red hat.

7:42So I'll type it in and to enter give it a moment to register.

7:46And now it says the system has been registered.

7:48What I now want to do is to say sudo subscription manager, attach and to enter

7:53and we can see

7:53the registration has been successful.

7:55Perfect.

7:56So if I just say sudo dnf repo list, we now have access to these particular

8:00repositories.

8:01And now what I want to do is I want to install Ansible core.

8:04So let me just clear the screen and I will now say it's sudo dnf install and

8:08let me just

8:09access out to clear the screen.

8:11And I will just say Ansible hyphen core.

8:13If I hit enter, give it a moment to pull in the information, I will just say

8:17why and to

8:18enter and there we go.

8:20So with that now done, what I should be able to do is to say Ansible dash dash

8:24version.

8:25And we actually see the Ansible version information right here.

8:28Now you'll notice for the purposes of recording, just to make things a little

8:31bit easier on

8:32the eye, I changed the color of the prompt.

8:34But that is certainly not anything you have to worry about yourself.

8:37What I'm now going to do is simply shut down the machine right now.

8:40So if I say shut down dash H now and to enter, we have now created our control

8:45machine.

8:46Let's now quickly spin up a device that is going to be managed by Ansible.

8:49So let's go to fail and new once again, follow the same procedure, install

8:53image and just

8:54walk through the same type of process.

8:56Choose a disk.

8:57If you want to use a minimal install, you can reduce these resources greatly.

9:01But for me, I'm just going to leave them at the defaults.

9:04And I will just call this rail blue box.

9:06The name itself doesn't actually matter, but just choose anything you so wish.

9:10So I'll pull this up, choose install and I'm just going to follow the same type

9:14of options

9:14and continue.

9:16So like I said with software selection, feel free to choose minimal install if

9:20you so wish.

9:21Same again when it comes to the root passwords.

9:23I'm just going to keep things really simple, choosing password one and I will

9:27select done

9:27and done again for the user creation.

9:30I'm again going to select nugget user and again, keeping it simple, just use

9:34password

9:34one again, making this user the administrator.

9:37Once that's done, begin installation.

9:39So once again, reboot the system.

9:41So on this particular box, we do not have to worry about registering the system

9:46nor do

9:46we have to worry about actually installing Ansible.

9:49And all I did on this particular device was change the host name to blue box to

9:53make it

9:54easier to follow.

9:55Now what I'm going to do is stop the video and in the meantime, I will create

9:59one more

9:59managed device in the exact same way that I created the blue box.

10:03The only difference being is that it's going to have a different host name

10:06known as yellow

10:07box.

10:08From now, I will stop the video, continue the task and I will see you in the

10:12very next video

10:12where we talk about SSH authentication.

0:00So friends, in this particular video, what we're going to do is set up SSH keys

0:05so that we can

0:06authenticate into our managed devices, that is going to be the blue box and

0:10yellow box

0:11from the Ansible control node without having to enter any passwords. And now it

0:17's not just that.

0:18What we want to do is on each of our machines, that is the Ansible control node

0:22, as well as

0:23the managed devices, we want to create a user called Ansible. And this is going

0:28to be a dedicated

0:29user account for Ansible to operate. Now it's not absolutely essential that you

0:34create

0:35a Ansible user, but realistically for managing things such as security, having

0:39this dedicated

0:40account really does keep things a lot cleaner. So the very first thing is we

0:44will create that

0:45Ansible account, we'll say it's sudo user ads dash M, and I will just say Ans

0:49ible. And then I

0:50will say it's sudo pass wd and then specify the account I want to create the

0:55password for,

0:56which is Ansible. If I hit enter, now what I'm going to do is specify the

1:00password that I want

1:01to use for the Ansible account. Now just to keep things really, really simple,

1:05I will alter

1:06as call the password Ansible. Okay, once again, not exactly best practices, we

1:10can see we're getting

1:10a warning that this is a bad password, but nevertheless, let's just stick with

1:14the word

1:14Ansible again. Okay, so we now have created this Ansible user, let's do the

1:19same thing on the

1:20other two machines. So I'm here on the blue box, let me just say sudo user ad

1:26dash m Ansible,

1:27type in the password of password one for super user privileges. And now I will

1:31create the

1:32password for the Ansible user so sudo pass wd Ansible. Again, the password is

1:36simply going to be the

1:37word Ansible. And let's just confirm that and to enter. Now let's go to the

1:42yellow box. Once again,

1:43let's just create the Ansible user and we'll give the Ansible user password of

1:48Ansible and once

1:48again just confirm that password. Now what I also want to do is to give the Ans

1:52ible user account

1:54access to the sudo command without having to type a password. Once again, we

1:58will handle this a

1:59little bit different in a real environment, but for simplicity and for the

2:03purposes of the

2:03examination, we are absolutely fine to do so. So let's just say sudo vice sudo.

2:07And if we scroll

2:08all the way down just below this part here that says route all equals all, all

2:13I'm going to do

2:13here is say Ansible, which is the name of the user accounts, and then say all

2:17equals a name

2:18within parentheses all. And then I would just say no pass wd colon and then the

2:24word all. So if I

2:25just write and quit, let's do the same thing on blue box and yellow box. So

2:29once again, sudo vice

2:31sudo and just type in the exact same information again. Perfect. So colon

2:35writing quits. And lastly,

2:37on the yellow box machine, we just sudo vice sudo and again, just type in the

2:41exact same content.

2:43Once again, saving with a wq. So if on my main machine, I just type ipadder, we

2:48can see the ip address

2:49happens to be 192168160.133. And we want to be able to reach the blue box and

2:56yellow box. So

2:57let's see what their IP addresses are. So once again, we just do ipadder on the

3:02blue box, we can

3:02see this is 192168160.134. And over on the yellow box, we are on 160.135. What

3:11I actually want to do

3:12now is to create some SSH keys for login. Now what I'm going to do is I'm going

3:16to create these keys

3:17as the answerable user sources, sudo su hyphen answerable and I enter, we can

3:22now see the username

3:23has changed to answerable right here. And what I'm going to do is say SSH hyp

3:28hen key gen and

3:29enter. That's going to tell me the file where it's going to save automatically.

3:33That is fine. So

3:34I'll just hit enter. It's going to ask me for a passphrase. Now in the real

3:38world, once again,

3:39we absolutely want to be adding a passphrase but for simplicity for the

3:43examination.

3:44Absolutely find you to leave this blank. So let's just hit enter and enter

3:47again. And now we have

3:49automatically generated our SSH key pair, the public key as well as the private

3:54key. Now what

3:54we want to be able to do is to share the public key with the blue box and the

4:00yellow box. This

4:01is going to allow us to authenticate in as the answerable user to those devices

4:05without having to

4:06type in the password answerable, which is going to be much, much better for us

4:10when working an

4:11in automated fashion. So all I will say is SSH hyphen copy ID. And then I will

4:17say answerable at

4:18192.168.168.134, which is the first machine the blue box machine. If I enter, I

4:25will say yes.

4:26And I will type in the password of answerable the very first time I'm doing

4:29this authentication.

4:30Perfect. We have now added the key to that particular machine for the blue box.

4:35And similarly, if I arrow up and do 135, I answer, I now say yes to add the

4:40fingerprint. I type in

4:42answerable again. I now log into the yellow box and transfer my public key over

4:47to that particular

4:48device. So now moving forward whilst I'm on the red box itself, the answerable

4:52control node,

4:53if I now just want to authenticate into that particular device, say for example

4:57, the blue box,

4:58I can just say SSH, answerable, and then type in the IP address of 192.168.134.

5:05And to enter,

5:06notice we authenticate straight away without having to type in the passphrase.

5:10I'm now on the

5:10blue box. See that right there? And again, if I exit out, arrow up, type 135, I

5:15enter,

5:16automatically, we just slide directly into the yellow box without having to

5:20type the password.

5:20That is exactly what we want. So now we have the basic setup of our lab

5:24environments. We have

5:25our three virtual machines. We have now created a dedicated answerable user for

5:29all three devices

5:31and have now configured passwordless SSH key authentication. With that now done

5:36,

5:36we are ready to begin talking about answerable.

0:00So friends, let's talk a little bit about what Ansible actually is.

0:04Well quite simply, at its most basic level, Ansible is an automation tool that

0:09has been

0:09developed by Red Hat.

0:11So think about the tasks that you would do as a Linux administrator.

0:15Perhaps you're managing 1000 servers and you want to go in and maybe modify the

0:19DNS

0:20settings, as opposed to having to log in to each device one by one by one.

0:24To manually make those configuration changes yourself, utilising a tool such as

0:29Ansible,

0:30you can have that change be automated all at once and have the system updated

0:34in the

0:35blink of an eye.

0:36Now the way Ansible operates, it uses something known as a push model.

0:40Let me just describe what that looks like.

0:42So imagine over here we had a Red Hat based system.

0:44This could just be a virtual machine and on that system you happen to install

0:49Ansible

0:50Looker.

0:51Here is going to be the machine that is going to manage all of the devices in

0:54the network.

0:55To say for example you had a whole ton of different servers that you're

0:58managing.

0:59One could be an Ubuntu machine, one could have it be Red Hat enterprise Linux

1:03as well,

1:03one could be Fedora, one could be Kali Linux, it doesn't actually matter.

1:06The point is if you happen to be a system administrator responsible for

1:10managing all

1:11these devices, having Ansible installed on one particular control mode will

1:15allow you

1:16to connect all of these devices at the same time and push out those updates.

1:21Now the reason why we refer to Ansible as using a push model to make its

1:24configuration

1:25changes is if you happen to have let's maybe say two machines over here that

1:28you're managing,

1:30the cool thing is that these devices here that happen to be managed by Ansible,

1:34this

1:34device here, these machines do not have to install any particular software you

1:39don't

1:39have to install Ansible here or here.

1:42You simply install Ansible on the device that is going to be performing the

1:46automation

1:47in that Ansible enabled device simply pushes out those changes to these

1:51different nodes.

1:53So all happens from here and is pushed outward towards the network, that is

1:56what we're referring

1:57to.

1:58Now as we move through this particular course there's going to be a strong

2:00emphasis on

2:01something known as YAML, pretty much this is a file format that is designed to

2:05be very

2:06human readable but it allows us to actually utilise programmatic logic, just

2:10like you

2:11can do so with say for example Python code except this time the code that we're

2:15writing

2:16quote unquote really doesn't look like code, it is very very easy on the eyes,

2:20really

2:20really easy for system administrators to look at and understand.

2:24Now with respect to Ansible the actual architecture can be broken down into

2:28four core components.

2:30The first component is the configuration file, typically this is going to be

2:34called Ansible.cfg

2:36and using this particular file you can specify global system settings, we'll

2:41get to see

2:41what this looks like in the very next video.

2:44Crucially though within the configuration file we can also specify where abouts

2:48we can find

2:49the next component of the Ansible architecture and that is the Ansible

2:54inventory.

2:55Now the inventory basically tells Ansible what devices should be managed.

2:59Now in our lab environment we have created two particular machines that are

3:03going to

3:03be managed by Ansible so in order to let Ansible know about this we would

3:07specify information

3:08about those devices in the Ansible inventory so that could include things like

3:12the IP addresses

3:13of those particular devices or maybe their host names, that's how Ansible knows

3:17which

3:17devices it should actually be connecting to.

3:20Now as you progress throughout this course we're going to learn that the

3:22inventory can

3:23be really really valuable, it can use things such as groups as well as by the

3:27way groups

3:28within groups otherwise known as nested groups but for now as our introduction

3:33we don't

3:33have to worry about that quite just yet, just understand that as a part of the

3:37Ansible

3:37inventory and it's one of the reasons why Ansible is so powerful.

3:41Now the third component I want to talk to you about, this is something known as

3:45variables,

3:46this is a very well known concept within programming because when we happen to

3:50be automating things

3:52whilst a lot of the information might be very repetitive we can just

3:55effectively have the

3:56automation system push out the same changes to all devices, we understand that

4:01with respect

4:01to particular configurations on particular systems we have a requirement for

4:06some configurations

4:07to be unique, basically they're not going to be the same, they're actually

4:10going to be

4:11varied depending on the device we are connecting to.

4:14So say for example we're managing two devices right here, let's just call it

4:17device one

4:18and device two and let's just say this is our Ansible machine right here that

4:21can connect

4:22to these devices.

4:23Now some things may be very common perhaps we're going to push out the same

4:26change to

4:26both devices, maybe that'd be safe for example some DNS server information

4:30perhaps they're

4:31both going to be updated to use the server 8.8.8.8 that is absolutely fine,

4:36however maybe

4:37at the same time whilst we're giving both devices the same DNS we want to

4:42update their

4:42IP address information and the IP addresses on these devices actually have to

4:47be unique

4:47we can't give the same IP address to both devices, as you're going to see the

4:51way we

4:51solve for this particular problem is via the use of these variables now we can

4:55have things

4:56known as host variables which are variable values unique to a particular host

5:01in the

5:01inventory but we can also have group variables these could be values unique to

5:05a particular

5:06group of devices perhaps we happen to have four devices in the UK and all of

5:11those UK

5:11devices have to get a particular NTP server that is different from all of the

5:16servers

5:16in the United States we can specify those UK unique values as a group variable

5:22and target

5:22all of the UK devices in the inventory.

5:25Once again we'll get to see this in more detail later on as we progress now the

5:29fourth and

5:30final component here this is known as the playbook and really this is how we

5:34tie everything

5:35together it is inside the Ansible playbook which happens to be written in YAML

5:40where

5:40we actually tell Ansible what it is we want it to do this is where we write our

5:45instructions

5:46you know like go and configure a DNS server go and update the NTP

5:49configurations go and

5:50create a whole bunch of new users on all of these devices so now we have a

5:54rough idea

5:55about what Ansible is and what it can do what we want to now do is to begin

5:58setting up our

5:59system so that we can then slowly begin automating tasks across our managed

6:04devices now in this

6:05particular skill we're not going to be looking at playbooks quite just yet or

6:09the concept

6:10of variable values but in the very next video we're going to be talking about

6:13the creation

6:14of that Ansible configuration file as well as the construction of our Ansible

6:19inventory

6:20once we have done that we will run Ansible against those devices to test for

6:24basic connectivity

6:26and that will have our lab up and running and put us in a really good place to

6:29continue

6:30on this journey throughout this course when we will begin using these playbooks

6:34to automate

6:35a whole bunch of really cool and useful tasks so with that said let's get going

6:39.

0:00Okay friends, so let's get hands on with Ansible.

0:03So the first component that we are going to talk about is that Ansible

0:07configuration file.

0:08So if you happen to search for Ansible configuration file, you can click this

0:13top link right here.

0:14And notice it says here that certain settings in Ansible are adjusted with this

0:20particular

0:21file Ansible.cfg. Now one thing to note, Ansible is going to seek to find this

0:26particular configuration

0:28file in a variety of different places, each with a greater priority than the

0:32other.

0:33Now it says here the pass where the configuration file is searched and listed

0:36as in the reference

0:37documentation. If we just click this link here, this here is effectively the

0:42locations and priority

0:43levels in which Ansible will look for this particular configuration file. So

0:47the first thing is that

0:48if you happen to set your own environment variable and point it to a particular

0:52location,

0:53this is the first and primary location where Ansible is going to seek to find

0:57this particular

0:58file. Now if you have not set this environment variable, the next place it's

1:03going to be checked

1:04is for a file called Ansible.cfg in the current directory. So whatever you

1:09happen to be running

1:10Ansible from, it's going to say hey, is there a file in the same directory

1:14right here called

1:15Ansible.cfg and if it is, then it's going to look to use the configuration

1:20specified within that

1:21particular file. Now if you do not have the Ansible configuration file within

1:26the current directory

1:27where Ansible happens to be running, the next location is going to be in the

1:32user's home directory.

1:33So we can see this via the tilde character, which we know is their home

1:36directory. Now if

1:37you've got a key now, you'll notice that we happen to have a dot before the

1:41word Ansible.

1:41Denoting that in this case here, this would actually be a hidden file. Now

1:45suppose you have not created

1:47any of these environment variables or the files in these particular directories

1:51, the general

1:52system way configuration file is going to be found in the exit directory and

1:55then into the

1:56Ansible folder and the file itself will simply be just called Ansible.cfg. That

2:01is the order of

2:02operation. Now in my case here, the practice that I tend to follow is just

2:05simply putting an

2:06Ansible.cfg file within the directory in which I am working. You can specify

2:11anything you so

2:12wish, but that is the practice that I am going to be following. If you don't

2:16use that particular

2:17practice, just at least understand the order of operations and where Ansible is

2:20going to look to

2:21find that particular config. Now if we search Ansible inventory, let's collect

2:26this link here.

2:27If we scroll on down, we can see some examples of Ansible inventories. Here we

2:31happen to have

2:32what is known as an Ansible inventory in the I and I format. The way we

2:36construct this is we

2:37specify our group names in square brackets. We have a group here called web

2:42servers and inside of

2:43the web servers just below, we specify the actual nodes which belong to that

2:47particular group.

2:48So food.example.com and bar.example.com, they happen to be web server devices

2:54and below we have to have

2:55a grouping of database servers, DB servers, and the nodes belonging to that

2:59particular group is

3:01one dot example.com, two dot example.com, and three dot example.com. Now in my

3:06opinion,

3:07this happens to be the easier way to happen to construct your Ansible inventory

3:11, just as

3:11really simple, doesn't cause any hassle. But ultimately, I would say it's best

3:16suited for

3:17simple inventories. If you just happen to have some groups, a few nodes

3:20belonging to those groups,

3:22then it is a very good way to structure your Ansible inventory. Below though,

3:26we can see the same

3:27type of information specified in the YAML format. Now the interesting thing

3:32here is with respect

3:33to YAML, we have a lot of emphasis on indentation. We'll talk about that a lot

3:37more in an upcoming

3:38skill. But basically, the indentation is very, very important if you happen to

3:42get the indentation

3:43wrong. The way the information is ingested is going to be completely different.

3:47And in fact,

3:48it can just be invalid and well not work. So in my opinion, this is a little

3:52bit more complex

3:53because an armor rose to follow is easier to get the syntax wrong. However, if

3:57you happen to have

3:58groups within groups, i.e. nested groups in a much more complex inventory,

4:03having that information

4:04represented in YAML format is actually a lot easier to look at visually because

4:08you can easily see

4:10via the indentation, which group belongs to which group. And to quickly assess

4:14visually,

4:15the order of the hierarchy. Now like I say for error purposes, it's going to be

4:19really quite

4:19simple. So I'm just going to stick to the i and i format. If you so wish, if

4:23you're more comfortable

4:23with YAML, then feel free to construct your inventory in that manner. So with

4:29that said,

4:29let's go and begin configuring our Ansible configuration file. Once again, I'm

4:33going to specify mine

4:35within my working directory. So right now I'm inside of the Ansible Home

4:39Directory for the Ansible

4:40user. If we do a listing, we can see we have no files or directories within

4:44here. So what I'm

4:45going to do is I'm going to create a particular file just called Ansible.cfg.

4:49If I create that,

4:50do a listing, now that file exists. But as we know, there is no content within

4:54that particular

4:55file. Let's add to it. So I will just say them Ansible, CFG. If I hide for

5:00insert, I can go into

5:01insert mode. And similar to the Ansible inventory, this is also going to be

5:05written via the i and i

5:06format. So I'm going to say within my square brackets, I'm going to create my

5:10default group,

5:10which is going to effectively denote my default settings. Now the first

5:14directive I'm going to

5:15give is specifying where abouts my inventory can be located. Now by default, if

5:19you did not

5:20specify an inventory location, the default is going to be in the Etsy directory

5:25. And then within

5:26the Ansible directory, there should be a file called hosts. So if we don't

5:30specify it here,

5:31Ansible will look to this particular file. But in order to keep things simple,

5:36I'm going to

5:36specify the Ansible, she looked within the current directory for a particular

5:40file called inventory.ini.

5:42Now I'm going to specify the directive for the remote user. This is basically

5:46going to be the

5:47username. The answer was going to use in order to access the remote machines.

5:52Now remember,

5:52we created a dedicated Ansible user account on the devices that we're going to

5:56manage.

5:57So right here, we're going to specify that Ansible should actually use that

6:00particular account

6:01when logging in. Now I'm going to say host key checking, we're going to specify

6:05that as false.

6:06We don't really care about key checking. And then I'm going to say deprecation

6:09warning pretty much

6:10very often. Ansible is going to give you warnings about modules and whatnot

6:14that happened to be

6:15outdated. We don't want to have to worry about that. So I'll just leave these

6:18warning messages

6:19set to false. So these are our default configurations. What I now want to do is

6:23to specify how Ansible

6:24can actually elevate privileges. You know the way you do when you happen to

6:28have a shell within a

6:29device, you can just say, so do and then type in the super user password. That

6:34is how we could

6:34perform an administrative system wide task. In the case here, we want to tell

6:38Ansible how to do that.

6:39So I'm going to say with 10 miles square brackets, once again, privilege

6:43escalation,

6:44basically how we can escalate our privileges. What I'm going to say is become

6:48equals true,

6:49which means we are going to seek to become the root user. I will specify how we

6:53actually elevate

6:54our privileges by specifying the become method. And I'll say we do that via the

6:58sudo commands.

6:58And then I'll say the become user is simply the root user. And I will say

7:03become ask pass.

7:05And I'll set that to the value false. We don't want to be asking for passwords

7:08after all.

7:08So with that now done, if I press escape and then colon wq to writing quit and

7:13then hit enter,

7:14we have now written this configuration file. Now as per the configuration file,

7:18we specified

7:19that there should be a file called inventory.ini within the same directory

7:23right now that doesn't

7:24exist. So let's just create it by saying touch inventory.ini. If I don't LS and

7:29now that file exists,

7:30and we want to actually specify the content of that file. Okay, so the very

7:34first group that I'm

7:35going to create is going to be the all group that is going to comprise of all

7:38of my devices in the

7:39way specify this group is by using square brackets. Now below here, I will just

7:43add in all of my

7:44devices. Now there are different ways we can solve this particular problem. Let

7:47's maybe say we've

7:48got the blue box here, I can tell Ansible is IP address by saying Ansible

7:52underscore host.

7:53And then given IP address of the actual device, so 192 168 dot 160 and do 134.

8:00And then for the

8:00yellow box, I would just say yellow box, then specify the Ansible host value is

8:04going to be

8:05the IP address of 192 168 dot 160 dot 135. This is perfectly valid. What you

8:11can also do by the way,

8:13which I would not recommend is just putting in the IP addresses of the devices

8:17themselves

8:17without any type of resolution going on. So basically you can get away with it,

8:22but I certainly

8:22wouldn't recommend you do that. Now the way I'm going to show you is we can

8:26also do it another way.

8:27If I just delete this right here, and I just specify the names of the hosts I'm

8:32going to be

8:32managing. So I've got my blue box and my yellow box. Now right now here, we do

8:36not have any IP

8:38address information. We're going to have the system resolve this via my Etsy

8:42host file on the

8:43control mode. So let's just save this right here. And if I say pseudo vim

8:46forward slash Etsy,

8:47forward slash hosts and enter, here's what I'm going to do. I'm going to type

8:51in IP address

8:52of my devices to have a static mapping. So 192 168 dot 160 dot 134. This is

8:58going to be my

8:59blue box. So I will type in the domain for blue box, let's just make one up of

9:03blue box dot example

9:04dot com. This doesn't actually exist by the way. And we can also have an alias

9:08shorthand of blue box.

9:10Similarly, I will say 192 168 dot 160 dot 135. And this one here is going to be

9:17yellow box dot

9:18example dot com and have the shorthand alias of yellow box. So now we have this

9:23static mapping on

9:24the system. So when Ansible looks up the name of blue box or yellow box, which

9:29it finds within

9:30its inventory right now, it's going to know to resolve that to the

9:34corresponding IP addresses.

9:36If I just happened to say, for example, paying blue box, notice what is

9:39actually happening.

9:40We're getting the resolution right here. We're actually getting back the

9:43correct IP address.

9:44And similarly, if I ping the yellow box, now we're getting the correct

9:48resolution and response

9:50from that particular machine. And if you swished, if you had many more devices,

9:54you could add in

9:55more groups. So for example, a UK group, and then add in all devices that were

9:59part of the UK group,

10:00if you swished, and again, add the USA group, like devices three, four and five

10:04. But as you know,

10:05right now, I don't have any of those devices. So let me just remove them for

10:09the moment.

10:09So with that now configured Ansible is ready to rock. We are all set up and

10:14ready to automate

10:15our lab environments.