14/10/2021, 17:21 lab-7-elb

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Exercise: ELB
The exercises are designed to be completed in your AWS account, and will have an associated cost.
For this reason, in addition to the written instructions, this course includes video recordings of the
exercises. If you intend to attempt the exercises, familiarize yourself with AWS pricing, specifically
Amazon EC2 pricing, Amazon S3 pricing, and Amazon DynamoDB pricing and the AWS Free Tier.
For this scenario, you have been tasked with setting up an Elastic Load Balancer and an
AutoScaling group, so your application can horizontally scale.
In this exercise, you will create an Application Load balancer and a launch template. Then, you will
set up an AutoScaling group that uses the Load Balancer and launch template you created. Finally,
you will test and stress the application and watch your application scale in real time.

Lab Steps
Stage 0 - Launch an EC2 Instance
1. Search for EC2 in the search bar at the top. Choose EC2.
2. Choose Instances under Instances at the left side panel.
3. Select the employee-directory-app-lab6 instance. Which should be in the Stopped state.
4. Choose Actions. Image and templates and Launch more like this.
5. At the top, choose 3. Configure instance.
6. Next to Auto-assign Public IP, choose Enable.
7. At the top, choose 5. Add Tags. Remove lab6 at the end of the value and append lab7
instead.
Example:

employee-directory-app-lab7

8. Choose Review and Launch. Choose Launch.

9. Leave the app-key-pair selected under Select a key pair. Select the acknowledgement.
10. Choose Launch Instances.
11. Choose View Instances. The instance should now show up under Instances. Wait for the
Instance state to change to Running and the Status check to change to 2/2 checks passed.
12. Next to Name, choose the checkbox to select the employee-directory-app-lab6 instance.
Under the Details tab copy down the Public IPv4 address.
13. Paste it into a new browser tab/window. You should see a Employee Directory placeholder.
Right now you will not be able to interact with it as it's not currently connected to the
database.
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Stage 1 - Create Load Balancer

1. In the EC2 console, on the left side panel under Load Balancing, choose Load Balancers.
2. Choose Create Load Balancer. Choose Create under the Application Load Balancer.
3. For the Name paste in app-elb . Under Availability Zones for the VPC, choose the app-vpc .
Select both Availability Zones.
Example: If you are in US West (Oregon) you would choose both us-west-2a and us-west-2b.
4. Choose Select a subnet and choose Public Subnet 1 for the first AZ and Public Subnet
2 for the second AZ.

5. Choose Next: Configure Security Groups.

6. Again choose Next: Configure Security Groups. Next to Assign a security group choose
Create a new security group. Next to Security group name paste in load-balancer-sg .
7. Remove the existing rule by clicking on the X at the right.
8. Choose Add Rule. For the Type choose HTTP. For Source choose Anywhere.
9. Choose Next: Configure Routing.
10. Under Target group next to Name paste in app-target-group .

11. Under Health checks expand Advanced health check settings.

12. Change the Healthy threshold to 2 . Change the Unhealthy threshold to 5 .

13. Change the Timeout to 30 . Change the Interval to 40 . Choose Next: Register Targets.

14. Under Instances select the checkbox next to the employee-directory-app-lab7 instance
and choose Add to registered.
15. Choose Next: Review. Choose Create. Once it's successfully created choose Close.
Note: Wait for the State to change from provisioning to active. Refresh the page while you
wait.
16. Select the app-elb and copy the DNS name and paste it into a notepad. Edit the DNS name
to include an http:// in front of the URL, to look like the following:
http://app-elb-000000000.us-west-2.elb.amazonaws.com

17. Copy the DNS name with http:// and paste it into a new browser tab or window. You should
see the employee directory application.

Stage 2 - Create launch template

Now that you can access your application from a singular DNS name, it's time to horizontally scale!
To do this, the first thing you need is a launch template.
1. Back in the AWS Management Console, search for EC2 in the service search bar. Then, choose
EC2. On the left side panel, choose Launch Templates under the Instances header.
2. Choose Create launch template. Under Launch template name paste in app-launch-
template .

3. Under Template version description paste in A web server for the employee directory
application .

4. Under Auto Scaling guidance check the box for Provide guidance to help me set up a
template that I can use with EC2 Auto Scaling.
5. Under AMI choose the Amazon Linux 2 AMI (HVM), SSD Volume Type.
6. Under Instance type choose the t2.micro.
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7. Under Key pair name choose the app-key-pair .

8. Under Network settings and Security group choose the web-security-group .

9. Expand Advanced details and under IAM instance profile. Choose

S3DynamoDBFullAccessRole .

10. Scroll down to User data and paste in the following information:

#!/bin/bash -ex
wget https://aws-tc-largeobjects.s3-us-west-2.amazonaws.com/DEV-AWS-MO-
GCNv2/FlaskApp.zip
unzip FlaskApp.zip
cd FlaskApp/
yum -y install python3 mysql
pip3 install -r requirements.txt
amazon-linux-extras install epel
yum -y install stress
export PHOTOS_BUCKET=${SUB_PHOTOS_BUCKET}
export AWS_DEFAULT_REGION=<INSERT REGION HERE>
export DYNAMO_MODE=on
FLASK_APP=application.py /usr/local/bin/flask run --host=0.0.0.0 --port=80

Change the following line to match your region:

Note: You can find this at the top right next to your user name.

export AWS_DEFAULT_REGION=<INSERT REGION HERE>

Example:
Note: US West (Oregon)

export AWS_DEFAULT_REGION=us-west-2

Also change the bucket variable to match your bucket:

export PHOTOS_BUCKET=<INSERT_BUCKET_NAME>

Example:
export PHOTOS_BUCKET=employee-photo-bucket-al-007

11. Finally choose Create launch template.

Stage 3 - Create ASG

1. Choose View Launch templates. On the left side panel, under the Auto Scaling header,
choose Auto Scaling Groups.
2. Choose Create Auto Scaling group. Under Auto Scaling group name paste in app-asg .
3. Under Launch template choose the app-launch-template . Choose Next.
4. Under Network and VPC choose the app-vpc . Choose Public Subnet 1 and Public
Subnet 2 . Choose Next.
5. Under Load balancing choose Attach to an existing load balancer. Under Attach to an
existing load balancer choose Choose from you load balancer target groups.
6. Under Existing load balancer target groups choose Select target groups. Choose the app-
target-group .

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7. Under Health checks choose ELB. Choose Next.

8. Under Group size change the Desired capacity to 2 .
9. Change the Minimum capacity to 2 .
10. Change the Maximum capacity to 4 .
11. Under Scaling policies choose Target tracking scaling policy.
12. Change the Target value to 60 . Change the Instances need to 300 . Choose Next.
13. Under Add notifications choose Add notification.
14. Under SNS Topic choose Create a topic. Under Send a notification to: paste in app-sns-
topic . Under With these recipients paste in your email address. Choose Next.
15. Choose Next. Choose Create Auto Scaling group.
16. You should have received an AWS Notification - Subscription Confirmation. In the email,
choose Confirm subscription.

Stage 4 - Test the application

1. Under Load Balancing on the left side panel, choose Target Groups. Select the name of the
app-target-group . Choose the Targets tab. You should see two additional instances
launching. Wait until the Status shows as healthy.
2. Under Load Balancing on the left side panel, select Load Balancers and select the app-elb .
Again, copy the DNS name and append http:// to the beginnng of it.
3. Paste it into a new browser tab or window. Append /info to the URL.
Example:

http://app-elb-0000000000.us-west-2.elb.amazonaws.com/info

You should be presented with Instance Info which will show you which instance_id and
availability_zone you are being routed to. Refresh the page a few times and you will notice
you are being routed to a different instance_id and availability_zone.
4. Now, you will need to stress the CPU of the instance in order to test Auto Scaling.
5. Next to Stress cpu: choose 10 min. At the top you will notice it now says Stressing CPU.
Note: Go grab a beverage as you wait :)
6. After the 10 minutes are up, go back in the EC2 Console. Under Load Balancing on the left
side panel, choose Target Groups. Choose the app-target-group . Choose the Targets tab.
7. You should see additional instances being spun up due to the stress test. You should also see
a notification email as well.

Stage 5 - Delete Course Resources

1. To ensure that you don't incur additional costs, please ensure that you delete all resources in
the AWS account you created.
2. In the EC2 console, on the left side panel, choose Auto Scaling groups. Select the app-asg
and select delete. Type delete in the text box to confirm your deletion.
3. In the EC2 console, on the left side panel, choose Load Balancers. Select the app-elb and
select Actions and then delete. Choose Yes, Delete.
4. In the EC2 console, on the left side panel, choose Target Groups. Select the app-target-
group and select Actions and then delete. Choose Yes, Delete
5. In the EC2 console, on the left side panel, choose Instances. Terminate all EC2 instances you
created in this course. Select the checkbox next to the instances you want to delete (all
instances starting with employee-directory-app ) and then select Instance State. Then,
choose Terminate Instance.
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6. In the DynamoDB console, on the left side panel, click on Tables. Then, click the circle next to
the Employees table. Choose Delete Table. Type in the word delete and select Delete.
7. In the S3 console, find the employee-photo-bucket. Select the circle next to the bucket you
created. Then, choose Empty. Type in permanently delete in the text field. Select Empty.
Choose Exit. Now, choose Delete. Type in the name of your bucket in the text field and
choose Delete bucket.
8. In the VPC console, on the left side panel, click on Route Tables. Select the checkbox next to
app-route-table-public and click on the Subnet Associations tab. Select Edit subnet
associations. Deselect the boxes next to both Public Subnets and click save. Select Actions
and then Delete. Then, choose Delete Route Table again. Follow the same steps for app-
route-table-private.
9. In the VPC console, on the left side panel, click on Internet Gateways. Select the app-igw and
choose Detach from VPC and choose Detach Internet Gateway. Then, click Actions and
select Delete Internet Gateway. Type in delete in the text field and select Delete Internet
Gateway.
10. In the VPC console, on the left side panel, select Subnets. Select the boxes next to Public
Subnet 1, Public Subnet 2, Private Subnet 1, and Private Subnet 2. Select Actions and then
delete subnet. Type delete in the text field. Then, choose Delete.
11. In the VPC console, on the left side panel, select Your VPCs. Select the checkbox next to app-
vpc. Select Actions and then Delete VPC. Type delete in the text field and then choose
Delete.

Lab Complete
Congratulations! You have completed the lab.
For feedback, suggestions, or corrections, please contact us at:https://support.aws.amazon.co
m/#/contacts/aws-training

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