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So friends, now that we know how to use basic variable substitution within our

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Ginger 2 templates,

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let's now take a look at a little bit more of an advanced subject, and that is

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utilizing

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loops within our templates. So with that said, let's just get to it. Now, one

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of the best places

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that I would reference that you go to if you want to learn how to use Ginger

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templating any more

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expressive manner, and that is to go to the actual Ginger 2 documentation

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itself. So if we collect

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the link for Ginger 2 documentation here. So as we can see here, we are
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the link for Ginger 2 documentation here. So as we can see here, we are

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presented with a table of

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contents. There are a whole number of different sections that we can explore,

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but if we scroll

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down to list of control structures right here and click this link, what it says

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here is that a

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control structure refers to all things that control the flow of a program. So

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we have things like

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conditional statements, but the thing that we want to be looking at is this one

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right here, a for loop.

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So a key point to understand is that when we want to utilize a loop within Ans

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ible,

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we just use the loop keyword. But ultimately, Ansible is acting as an
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we just use the loop keyword. But ultimately, Ansible is acting as an

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abstraction layer presenting a

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yaml interface to interact with the underlying Python code and the underlying

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Python code is

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utilizing a for loop. So we can actually see here the syntax is using the

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keyword for and then we

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specify a variable here, which can be any name you so wish, although is a good

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idea and good practice

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to have something sensible, some descriptive. And then we have the keyword in,

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and then we target

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the iterable object that we want to loop over. So an iterable object, that is

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anything that can be

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broken down into smaller components, such as an array can be broken down into
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broken down into smaller components, such as an array can be broken down into

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individual elements

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within the array. This is what we're talking about here. Now, when we happen to

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utilize the

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variable here, given the name user, and then this particular variable here, as

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denoted by the name

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user gives us access to each individual element. So if that element also has

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multiple keys, we can,

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in this example here, use dot notation to access the username key. Now the

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interesting thing to

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note is that if you happen to have experience with Python, this part here looks

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very, very familiar.
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very, very familiar.

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But with Python, the for loop is going to automatically close itself. In the

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case of ginger too, that is

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not true. We actually have to be very explicit and manually close each for loop

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that we happen to open.

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And we do this as we can see here with this end for statement, again, within

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the colubracing

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percentage signs. So if we happen to have multiple loops, ie nested loops, we

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're also going to happen

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to have multiple end for statements. That's kind of the rules here at play. Now

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, very, very important.

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Recall with respect to our variable substitution, we could just use our double
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Recall with respect to our variable substitution, we could just use our double

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curly braces.

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When we want to be using these control structures here within ginger too, we're

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going to have our

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curly brace and then our percentage sign. See that? Colubrace percentage. And

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then the actual control

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structure, whereas when we're actually referencing the actual variable, which

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we're looping through

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here, we still use the double curly braces. That is the gist of it. Now, if you

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happen to have

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familiarity with Python, this will be much more natural to you. Whereas if your

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only exposure is

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to answerable itself directly, this might take a few tries just to get
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to answerable itself directly, this might take a few tries just to get

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comfortable. But like I say,

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with everything, it just is a little bit of practice to get familiar. So let's

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actually add to our

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variable files and begin building out a larger configuration file rendered via

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the use of loops

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within our logic. So check this out then. So let's go into the host files here

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and let's go into

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blue box dot yml. So all I will do is I'll add in some new information. Okay.

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So let's add in some

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users here. Now this doesn't actually have to be accurate. Like you say, we're

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just creating some

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dummy configurations just to test out how we can use these templates. So let's
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dummy configurations just to test out how we can use these templates. So let's

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just say on the

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blue box here, let's imagine we happen to have a user called Ansible, which we

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actually do.

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And then we'll specify the group to which Ansible belongs to. So we'll say it

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belongs to the Ansible

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group, as well as at the real group. Again, we're not caring about the actual

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accuracy here,

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I think they're a little bit off. Let's add a new name. We'll have the nugget

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user. The group's

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belonging here is going to be nugget user, as well as let's just say the real

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group as well.

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And let's imagine it's also part of the, oh, I don't know, let's say the

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marketing department.
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marketing department.

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Okay. And let's maybe add another name, let's just say go with James, add to

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the grips of James.

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We have the primary James group, James can be part of the real group, and James

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can be also in the

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engineer group. Okay. So write and quit, let's go into the yellow box here, let

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's do a similar

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thing. So we'll add in the users, add the name of once again the grips will be

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Ansible, as well as

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we'll add in the nugget user as well here, add on nugget user and we'll, and

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let's just say on this

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particular device, instead of James, we have a user called Knox. In fact, let's
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particular device, instead of James, we have a user called Knox. In fact, let's

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just add marketing

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here just for a little bit of consistency, not that it matters. So Knox is in

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the Knox primary

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group, Knox is also part of the wheel, and let's say Knox is in the programming

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department. Okay.

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So check this out. Let's go back to our template right here. So I want to

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invoke my loop. Now remember

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how to do this, curly brace percentage time. And now I specify my loop

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contracts, I'll say four,

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and now I can choose a variable of any name I so wish. So I could say for pizza

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, and the users,

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then I have my percentage sign and curly brace. And the reality is this is
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then I have my percentage sign and curly brace. And the reality is this is

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absolutely valid.

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We have our four keyword, the N keyword, and the actual object we're going to

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look through,

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which is going to be the users key, which is corresponding here, this

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particular key here.

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So that gives us access to each element, which is this one here, the first

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element,

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and then the second elements. And then we can call the individual keys within

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that particular

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elements of say, for example, upon first iteration, we could grab the name key.

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The key point to know,

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though, is that each element in the array is going to be represented with

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whatever keyword you use
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whatever keyword you use

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here. Now right now, I'm using pizza just to show how flexible this can be. It

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's not actually a

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very good thing because it's not actually descriptive of what we're looking

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through,

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not exactly best practice, but it can work just to show you. So if I wanted to

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actually get the

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variable here, I could just have my double curly braces and say pizza, which

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gives me access to

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each iteration and then call the key that I want to target, which in this case

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here would be the

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name key. Okay, this would actually print out the names. Now what am I going to

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do here? Because I

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have opened my for loop, I'm going to have to close it. So I'll have my curly
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have opened my for loop, I'm going to have to close it. So I'll have my curly

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brace and then

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a percent and then I will say end for and then again, curly brace percent. This

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here should be

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absolutely valid. So let's try this. And if I just press escape, colon wq,

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writing quits,

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let's see the back. If I clear the screen and I rerun the same playbook, which

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we'll call the

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same template just a modified version of the templates, let's hit enter and see

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what happens.

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Okay, we seem to have a change on both devices. Let's go and confirm. So on the

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yellow box,

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we're going to the 10 directory that's done LS and great for config. Once again
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we're going to the 10 directory that's done LS and great for config. Once again

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, that version

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that be overwritten with the new config and check this out right here, we

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actually have rendered

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the correct template. Here is all the original stuff. But down here we have on

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my system, I have

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the following users, Ansible, nugget user and Knox. Notice the way we were able

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to correctly parse

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out the names, despite using a rather poorly worded variable name and pizza.

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Okay, didn't

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actually matter. Again, we go to the blue box here. Let's cd into temp. Let's

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cat config.txt.

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This time we have the original text. And then again, we have added on on my
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This time we have the original text. And then again, we have added on on my

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system, I have

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the following users, Ansible, nugget user and James this time. Now here is an

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interesting thing.

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Suppose you want to have another loop that's going to look through all of the

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groups that

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each member belongs to. This is going to require a nested loop. This actually

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is quite interesting

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and may be confusing when you first see it because we have two different loops.

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We're going to have

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to close both of them with two end four statements. So let's go and check this

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out. So let's go back

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into the template. Now what I'm going to do here is I'm going to just change
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into the template. Now what I'm going to do here is I'm going to just change

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the name of the variable

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pizza to something that actually is descriptive now I've actually highlighted

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the ability of

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being able to choose anything user wish. And I'll just use a much more

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conventional name such as

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the word user. So I'll say for user and users. Okay, now I'm going to have to

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change what I'm

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calling here and reference the name of the variable so that it's match up. So

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we have user dot name.

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As I loop through each of these users, I also want to add in the group

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membership for each user. Okay,

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and that was just a little bit of indentations to make things a little bit
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and that was just a little bit of indentations to make things a little bit

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clearer. And I'll just

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say groups colon and then I'm going to have my programmatic logic once again.

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So color brace percent

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and now I'll say for and again choose any variable use a wish but because it's

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a little bit more

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descriptive, I will say group and and what am I actually looping through? Well,

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I'm actually within

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a nested loop. So I'm going to have to call the user variable here which access

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es each elements

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again before this would have actually been pizza as I discussed but now it's

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back to being user.

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And what is the actual key that gives me all of the array objects? I eat all of
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And what is the actual key that gives me all of the array objects? I eat all of

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the groups what we

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can see here from the actual documentation. This is the first iteration and if

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we grab the groups key

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that gives us access to this iterable object which is answerable and we'll

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which we'll look through

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and then upon second iteration we get the nugget user again grab the groups key

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and then we get

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this element which we can look through. So we're going to say user dot groups

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and again we're

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going to have a percentage sign and color brace and just to make things a

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little bit more readable

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I'll have let's say a hyphen and then just give the name of the actual group.
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I'll have let's say a hyphen and then just give the name of the actual group.

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So I'll have my double

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color brace and then give the variable name group. Once again choose any name

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you so wish for this

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group just happens to be descriptive now because we have opened our four

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statements here. This is

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actually now being closed off with this particular four statement the next one

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to it the one below

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but we still have this particular four statement opened up and that means we're

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going to have to

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close it again so it's going to be closed at the very end. So we just say in

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four percentage

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and color brace if I now escape writing quits clear the screen say answerable
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and color brace if I now escape writing quits clear the screen say answerable

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hyphen playbook

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render test at YML hit enter and we can see from the recap we have updated the

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files.

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Let's go to the yellow box here let's cut the file if I hit enter look at this

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right here.

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Now we have the original text followed by on my system I have the following

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users

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answerable and then the groups here and then we have iterated through all of

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the groups

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then we have nugget user iterated through all the nugget user groups and then n

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ox we have iterated

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through all of noxes groups now if we go on to the other machine we should see

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something very

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similar but this time actually we should see the James user in amongst the
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similar but this time actually we should see the James user in amongst the

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configuration.

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So let's cut the file as we can see here there we go right there we have answer

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able with the

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answerable groups nugget user with all of their groups and James with all of

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James's groups.

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So that is how we can utilize groups within ginger tool like I say if this is

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your first exposure

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this can be a little bit overwhelming the key here as always is just a little

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bit of practice a

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little bit of familiarity but now that we've got that under a belt the next

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thing I want to talk

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to you about is how we can use conditional logic again this time within our
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to you about is how we can use conditional logic again this time within our

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ginger tool templates.