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Welcome back to BackSpace Academy. In
this lab we're going to be creating a

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Nodejs
Lambda function using the Lambda

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console. Once we've done that we're going
to edit that that Lambda function with

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our own nodejs application code and then
we're going to invoke and test that

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Lambda function by sending a request to
it and seeing what it responds to and we

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can do all that again using the Lambda 
console. Let's get into it. okay so

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starting off in the Lambda console. Again
we get there from services and select

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Lambda. Not a problem there. I'm just
going to open up this toolbar on the

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left here and go to functions and then
create function. We're going to be

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authoring this from scratch. We're going
to be using our own code so it will

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provide us with just a blank canvas to
use we will call the function 

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backspace - Lambda- lab and we're going to be
using the nodejs runtime and we need to

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choose or create an execution role.
I've got an existing role here you

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probably will have this as well called
lambda basic execution. If you don't

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already have this role then there are
instructions in the lab notes on how to

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create that role. So that looks fine now
and we're going to create that function.

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Okay so that has successfully created
our backspace - Lambda lab function.

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If we scroll down we can see that 
bare bones code that has been put in

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here by AWS. We're not going to use it.
We're going to use our own code which

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I'm just now going to copy from the lab
notes and paste that in there. I'll just

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bring this down a little bit so we can
see it better. Okay so what we've got

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here is that we've got our our handler
function or handler module. So we 

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have an exports
and it's going to export this handler

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and that name handler can be anything
you want. It doesn't have to be called

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handler but you need to remember what
you call it so you can refer to it later

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on.
So this handler module is going to be

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receiving and something called an event.
So it's going to receive it a JSON

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object we're calling it event here and
inside that will have key one key two and

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key three. So we need to, when we send
that to it, we need to make sure that

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those fields of key one key two and key
three are there. So the first thing we're

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going to do is create that variable
called response and then we're going to

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console log out that the function was
invoked successfully. Now obviously a

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Lambda function doesn't have a screen so
it's not going to be a console log

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screen that we can view, other than in
the the actual management console here.

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So those console logs will be output
to a cloudwatch log group. So what

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we're going to do now is we're going to
try and create the response which will

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be consisting of item 1 item 2 at item 3
and we're just going to say received and

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whatever key one key two and key 3 are. So
what did we receive. We're just going to

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send back to the requester. We're going
to console out the returned response and

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then we're going to turn that response
into a string so we can read it and

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again that will go to the cloudwatch
logs group and then we're going to

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return that response.
If there's an error we'll just

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console.log out the error and then
return the response. So that all looks

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fine and that should work perfectly.
First thing that we need to do now that

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we've modified our Lambda function is
that we need to save it. So now that

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we've saved it we can scroll up and we
can test our Lambda function. So what

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we're doing here is we're configuring a
test event. So what lambda or what the

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lambda console will do for us, it will
send that request to our lambda function

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in the format that we that we specify
here. So we'll give it a name first just

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going to call a test and I'm going to
change this key one key two and

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key three values from value one value two

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and I'm just copying here from the lab
notes and I'm going to change that. I'm

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going to change that to milk eggs and
bread. So we can clearly see that the

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actual test has worked and our code has
worked. Just going to click on create to

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create that test. Now that the test has
been created we can run that. So I just

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click on test and here we can see that
the execution results are successful.

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We'll expand the details. Now this here
is what was returned from our Lambda

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function. It's item one received bread
received eggs received milk, exactly how

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we expected from our code. What we can
also see is it is the output from our

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console.log commands are going to be
listed here. So we can see here

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we've got function loaded successfully
and then returning response and then the

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string of that response
converted to a string and outputted here

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to the console and also that it's been
stored in a cloudwatch log group. So we

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click here that will open CloudWatch
and we can have a look at that 

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Cloudwatch log group. So there it is. There
that top one and there we can see that

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the function loaded successfully and
also console logged out returning

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response and then the string of that
response. So that's a very handy tool if

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you have any issues with your Lambda 
function, you can have a look at your

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logs and see what the console log output
is and see if there's any errors coming

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up here that will be output it to the
console or to the CloudWatch log group.

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So just going to close that out there
now that brings us to the end of this

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lab what I'll do now is clean it all up.
So actions delete that function and

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there we go it's gone. So that brings us
to the end of this quite a quick clip

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and I look forward to seeing you in the
next one.