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Okay friends, so now that we understand the general logic behind the

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conditional statement,

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let's now see how Ansible actually implements these conditional statements.

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So let's go directly to the Ansible documentation.

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So let's go to the big Google machine and if you just search for Ansible

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conditionals,

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you will be taken to this particular link here. So let's click on this.

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So it says here in a playbook, you may want to execute different tasks or have

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different

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goals depending on the value of a fact, a variable or the result of a previous
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goals depending on the value of a fact, a variable or the result of a previous

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task.

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Basically, at its core, all we're seeing here is we may want to do different

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things

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depending on certain conditions. Now we can see here that Ansible uses

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something known as

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Ginger2Tests and filters, we'll talk about that in a later scale. But for now,

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what we are going

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to focus in on is this part here, basic conditionals with when. Quite simply,

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the when keyword is

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going to allow us to specify when something is true, it really kind of similar

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to what we talked

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about in the previous video, when we asked the question if something is true.
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about in the previous video, when we asked the question if something is true.

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So let's just look

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at the documentation here to see some examples. Let's maybe go to conditions

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based on variables.

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So we can see we have a really silly but fun example here within the Ansible

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docs, we have a

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variable with a key called epic and the corresponding value true. We also have

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a key called monumental

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and the corresponding value. Yes. So let's look at the task. Now the first one

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here happens to use

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multiple conditions. Let's just forget about that for the moment. Let's focus

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on this one here.

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The name of the task is run the command if epic happens to be false. So all we
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The name of the task is run the command if epic happens to be false. So all we

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're going to do

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here is to use the Ansible built in shell module to accurate the command. This

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certainly is an epic

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only when we have a particular condition. Now in the case here, as per the

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example, we actually

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have some type of inversion, we say not epic, which is pretty much just syntax

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specifying

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that the epic value should be false. Now right now the epic value is set to

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true. And as such,

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this particular condition here doesn't actually match the condition specified
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this particular condition here doesn't actually match the condition specified

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within the variable.

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Therefore this particular shell command is not going to execute. So it's really

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all about the use

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of this when keyword and specifying a particular condition, which is going to

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inform what is going

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to happen with the task specifying the condition. Now just below we saw this

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use of the word not

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and correspondence with the condition epic. What we actually saw here was a

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logical operator in

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use. So the logical operators are the and operator, the or operator. And as we
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use. So the logical operators are the and operator, the or operator. And as we

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just saw there,

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the not operator. Now by default, when we have multiple conditions, the logical

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operator at

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play that is going to be assumed as the and operator. And the way you pass this

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to Ansible is in the

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form of a list. So let's take this particular example that we have right here.

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Okay. So the

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name of the task is to shut down sent to us six systems. So this is something

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we're testing for

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very, very explicitly. It has to be a sent to a system. And it also has to have

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version six.

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See that both of these have to be true. So let's look at the actual condition
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See that both of these have to be true. So let's look at the actual condition

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here as specified

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via the when keyword once again, as highlighted in the documentation, we

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specify this via a list.

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So here we have it right here and array object. So the conditions that have to

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be true here

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is the answerable distribution. And don't worry about this syntax. Ansible

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facts,

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we'll talk about that later on. This is just simply a way to gather information

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about an

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Ansible system. So in this case here, we're just testing the distribution. If

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that returns the

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values sent to us, that is one condition. And because this is true, we can now
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values sent to us, that is one condition. And because this is true, we can now

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test the next

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condition, which is as the distribution major version equal to the value six,

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if that is also true,

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then as a consequence, we have passed the test, because in this case here, we

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have the and operator,

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this has to be true. And this has to be true. And when that happens, what we're

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going to do is

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send the shutdown dash T no command to any devices that match that criteria.

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And essence,

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shutting down all sent to us version six systems. So let's take a look at a
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shutting down all sent to us version six systems. So let's take a look at a

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simple example. Then,

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okay. So like I say, a classic example to use with respect to a conditional

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statement is to

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highlight the differences in package management across Linux systems. We use D

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NF for Red Hat

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devices, and we would use apt for the Debian based devices. Now, as it trans

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pires, both of the

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devices in our inventory happen to be Red Hat enterprise Linux. Therefore, they

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both use DNF.

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So we're not going to use this as an example. What I'm going to do is I'm going

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to go into my

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inventory, and I'm going to add in some additional groups. So let's imagine we
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inventory, and I'm going to add in some additional groups. So let's imagine we

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have a UK group,

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and imagine that the blue box is located in the United Kingdom. And similarly,

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let's have a USA

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group. And let's imagine that yellow box resides in the USA. Now, of course,

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that says very, very

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trivial. We only have two devices, one of each in each group. But you could

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easily imagine if we

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happen to have thousands of devices, maybe say purple box and green box. They

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could be in the USA.

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Whereas in the UK, we can have blue box, pink box and a whole bunch of others.

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You kind of get

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the drift. We don't have to be limited to one device per group. But in this
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the drift. We don't have to be limited to one device per group. But in this

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case here, we only

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have two devices to manage. So let's just write out the changes. Here we can

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see we have now

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updated the inventory. What I want to do is I want to test it via a conditional

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statement. So

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let's just call this condition dot yml. If I go into insert mode, have my three

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items at the top,

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give my play a name, creating files based on location. So what I'm going to do

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is I'm going to target

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all of my devices. And I will specify the tasks that I want to happen. So the

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name of the task

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is going to be create UK file for UK devices. And I'm going to use the Ansible
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is going to be create UK file for UK devices. And I'm going to use the Ansible

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built in shell module.

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And all I'm going to do is say echo, I am a UK device. And I'm going to

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redirect that

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into the 10th directory. And I'll put it into a file called location dot txt.

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Now similarly,

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I'm going to have another one, a rather another task. And I'll just say create

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USA file for USA

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devices. Similarly, we're going to use the same module Ansible built in shell.

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And we're just

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going to echo this time. I am a USA device and redirect that into temp location
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going to echo this time. I am a USA device and redirect that into temp location

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once again.

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Now the crucial thing to note here is that we don't want this to happen for

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both devices as

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it's going to happen right now. So here is the condition that I'm going to test

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. I'm going to use

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the condition when I'm going to have the keyword UK. And I'm going to specify

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that when we have UK

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inside of the group underscore names. Now where on earth am I getting group

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underscore names from?

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That just happens to be what is known as a magic variable. Basically, this is

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just one of the
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just one of the

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special variables that Ansible comes shipped with that holds particular

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information about the

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device within the inventory. Now we'll talk more about magic variables later on

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. So definitely

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don't get worried thinking I would never known to use that particular magic

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variable. So all I'm

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doing here is looking at all the groups that the device happens to be a member

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of. And if there

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happens to be a group called UK in the list of groups to which they are a

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member, that condition

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therefore would be true. And as a consequence, we are going to run this

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particular shell command.

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I am a UK device and redirect into location.txt. So if you happen to have a
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I am a UK device and redirect into location.txt. So if you happen to have a

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device in the USA,

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which is not in the UK group for that particular device, this condition here is

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going to be false.

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And when it's false, that means that the command above, i.e. echo, I am a UK

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device is not going

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to execute. Now we also want to do a similar thing for the below task. So we'll

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add in the when keyword.

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Again, we'll have our double quotation marks with single quotation marks

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contained within

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specifying USA once again in the group names, magic variable. So therefore,
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specifying USA once again in the group names, magic variable. So therefore,

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this particular

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command is only going to execute for devices that belong to the USA group. Okay

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, so let's just

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write and quit. If I just say answerable playbook condition dot yml and to

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enter

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answerable executes. And as it transpires, answerable is actually skipped

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absolutely everything. So

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that wasn't supposed to happen, but I know exactly why it did happen. And this

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is quite good actually.

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This is very, very important. We can see here for the task create UK file for
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This is very, very important. We can see here for the task create UK file for

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UK devices.

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Answerable has skipped both the yellow box and the blue box. And for the next

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task, create a USA

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file for USA devices. Answerable once again has skipped both devices. Pretty

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much answerable has

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denoted that the when condition in both cases happened to be false. Now why

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exactly is that?

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Well, let's just look briefly at the inventory once again, if we cat the file.

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Check this out. The UK group happens to be UK in lower case and the USA group

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happens to be in

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lower case as well. Whereas if we look at the actual conditions as specified
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lower case as well. Whereas if we look at the actual conditions as specified

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via the answerable

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playbook, the condition here is USA in capital letters and UK in capital

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letters. So pretty much

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we don't have a capital letter UK group. So this is false for both devices and

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we don't have a

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capital letter USA group for both devices. So it's going to be skipped twice.

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So let's just briefly fix this. And if I go into insert mode and I'll just

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change this to

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lower case, scroll on down and also change USA to lower case. Let's just exit

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to the

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scape, right and quit, clear the screen, arrow up and let's rerun the playbook.
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scape, right and quit, clear the screen, arrow up and let's rerun the playbook.

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Aha, this is much better this time to look at the output here. It says for the

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task creating UK

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file for UK devices, it has skipped the yellow box but it changed the blue box.

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That's because

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the blue box happened to be a member of the UK group. Whereas when you go down

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to the next task,

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create a USA file for the USA devices, the inverse is true. We have skipped the

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blue box,

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whereas we have changed the yellow box again based on the conditions. So if we

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go to say,
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go to say,

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for example, the blue box, we should have a UK file as specified like a say in

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our inventory,

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blue box is UK, yellow box is USA. So and say the blue box, we go to the 10th

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directory,

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we have this file called location dot txt. If we cat this fail, it says here, I

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am a UK device,

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as expected. Let's go to yellow box here, we see the enter the 10 directory, do

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an LS,

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we have the location fail, let's cat this fail and as we can see here, for the

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yellow box,

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we have applied the text, I am a USA device.