Launching an EC2 instance in AWS - Mini Project: Build & Apply

Launching an EC2 instance

📖 Scenario: You are setting up a simple virtual server in the cloud using Amazon Web Services (AWS). This server will run a basic web application. To do this, you need to launch an EC2 instance, which is like renting a computer in the cloud.

🎯 Goal: Create a configuration to launch an EC2 instance with a specific name, instance type, and Amazon Machine Image (AMI) ID.

📋 What You'll Learn

Create a dictionary called ec2_instance with keys 'Name', 'InstanceType', and 'ImageId'.

Add a variable called instance_count to specify how many instances to launch.

Write a loop that creates a list called instances containing instance_count copies of ec2_instance.

Add a final configuration dictionary called launch_config that includes instances and a Region key.

💡 Why This Matters

🌍 Real World

Launching EC2 instances is a common task when deploying applications or services in the cloud. This project simulates preparing the configuration before actually launching servers.

💼 Career

Cloud engineers and developers often write scripts or use configuration files to automate launching and managing cloud resources like EC2 instances.

1

Create the EC2 instance data

Create a dictionary called ec2_instance with these exact entries: 'Name': 'MyWebServer', 'InstanceType': 't2.micro', and 'ImageId': 'ami-0abcdef1234567890'.

AWS

# Create the EC2 instance dictionary with Name, InstanceType, and ImageId
# Your code here

Hint

Use curly braces to create a dictionary with the exact keys and values.

2

Set the number of instances to launch

Create a variable called instance_count and set it to 3 to specify launching three instances.

AWS

ec2_instance = {
    'Name': 'MyWebServer',
    'InstanceType': 't2.micro',
    'ImageId': 'ami-0abcdef1234567890'
}
# Set instance_count to 3
# Your code here

Hint

Just assign the number 3 to the variable instance_count.

3

Create a list of instances

Use a for loop with variable i and range(instance_count) to create a list called instances containing instance_count copies of ec2_instance.

AWS

ec2_instance = {
    'Name': 'MyWebServer',
    'InstanceType': 't2.micro',
    'ImageId': 'ami-0abcdef1234567890'
}
instance_count = 3
# Create an empty list called instances
instances = []
# Use a for loop to add ec2_instance copies to instances
# Your code here

Hint

Start with an empty list and add the same dictionary multiple times using a loop.

4

Add the final launch configuration

Create a dictionary called launch_config with keys 'Region' set to 'us-east-1' and 'Instances' set to the instances list.

AWS

ec2_instance = {
    'Name': 'MyWebServer',
    'InstanceType': 't2.micro',
    'ImageId': 'ami-0abcdef1234567890'
}
instance_count = 3
instances = []
for i in range(instance_count):
    instances.append(ec2_instance)
# Create launch_config dictionary with Region and Instances keys
# Your code here

Hint

Use a dictionary with the exact keys and values as specified.

Practice

1. What does launching an EC2 instance in AWS create?

easy

A. A storage bucket

B. A virtual server in the cloud

C. A database instance

D. A physical server in your office

Solution

1. Step 1: Understand EC2 purpose

   EC2 stands for Elastic Compute Cloud, which provides virtual servers.

2. Step 2: Identify what launching means

   Launching an EC2 instance means creating a virtual server in AWS cloud.

3. Final Answer:

   A virtual server in the cloud -> Option B

4. Quick Check:

   EC2 instance = virtual server [OK]

Hint: EC2 = virtual server, not physical hardware [OK]

Common Mistakes:

• Confusing EC2 with physical hardware
• Thinking EC2 creates storage or database
• Mixing EC2 with S3 storage

2. Which AWS CLI command is used to launch a new EC2 instance?

easy

A. aws ec2 run-instances

B. aws ec2 start-instance

C. aws ec2 create-instance

D. aws ec2 deploy-instance

Solution

1. Step 1: Recall AWS CLI commands for EC2

   The correct command to launch EC2 instances is 'run-instances'.

2. Step 2: Eliminate incorrect commands

   Commands like 'create-instance', 'start-instance', and 'deploy-instance' do not exist or are incorrect.

3. Final Answer:

   aws ec2 run-instances -> Option A

4. Quick Check:

   Launch EC2 = run-instances command [OK]

Hint: Remember 'run-instances' to start EC2 instances [OK]

Common Mistakes:

• Using 'create-instance' which is invalid
• Confusing 'start-instance' with launching
• Assuming 'deploy-instance' is a valid command

3. What will happen if you run this command?

aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro --key-name MyKeyPair --security-groups MySecurityGroup

medium

A. Deletes the specified AMI image

B. Creates a new security group named MySecurityGroup

C. Launches one t2.micro EC2 instance with specified settings

D. Starts an existing stopped EC2 instance

Solution

1. Step 1: Analyze the command parameters

   The command uses 'run-instances' with image ID, count=1, instance type, key pair, and security group.

2. Step 2: Understand the command effect

   This command launches one new EC2 instance of type t2.micro with the given AMI and security settings.

3. Final Answer:

   Launches one t2.micro EC2 instance with specified settings -> Option C

4. Quick Check:

   run-instances with parameters = launch instance [OK]

Hint: run-instances with --count 1 launches one instance [OK]

Common Mistakes:

• Thinking it deletes or modifies AMI
• Confusing security group creation with usage
• Assuming it starts an existing instance

4. You run this command but get an error: InvalidKeyPair.NotFound. What is the likely cause?

aws ec2 run-instances --image-id ami-87654321 --count 1 --instance-type t3.small --key-name WrongKey --security-groups Default

medium

A. The key pair named 'WrongKey' does not exist in your AWS account

B. The AMI ID is invalid

C. The instance type t3.small is not supported

D. The security group 'Default' is missing

Solution

1. Step 1: Understand the error message

   'InvalidKeyPair.NotFound' means the specified key pair is not found in your AWS account.

2. Step 2: Match error to command parameters

   The key-name 'WrongKey' likely does not exist or is misspelled, causing the error.

3. Final Answer:

   The key pair named 'WrongKey' does not exist in your AWS account -> Option A

4. Quick Check:

   InvalidKeyPair error = missing key pair [OK]

Hint: Check key pair name spelling if InvalidKeyPair error occurs [OK]

Common Mistakes:

• Assuming AMI or instance type caused the error
• Thinking security group 'Default' is missing
• Ignoring key pair existence in the region

5. You want to launch 3 EC2 instances with the same settings but different subnet IDs for high availability. Which approach is best?

hard

A. Use aws ec2 create-subnet to create three subnets and launch one instance

B. Run one aws ec2 run-instances command with --count 3 and a single --subnet-id

C. Launch one instance and then clone it twice manually

D. Run three separate aws ec2 run-instances commands, each with a different --subnet-id

Solution

1. Step 1: Understand subnet and instance launch

   Each EC2 instance can be launched in only one subnet at a time.

2. Step 2: Plan for multiple subnets

   To launch instances in different subnets, run separate commands specifying each subnet ID.

3. Step 3: Evaluate options

   Run three separate aws ec2 run-instances commands, each with a different --subnet-id. This runs three commands with different subnet IDs, ensuring instances spread across subnets.

4. Final Answer:

   Run three separate aws ec2 run-instances commands, each with a different --subnet-id -> Option D

5. Quick Check:

   One subnet per instance, multiple commands for multiple subnets [OK]

Hint: One subnet per instance, use multiple commands for multiple subnets [OK]

Common Mistakes:

• Trying to launch multiple subnets in one command
• Assuming cloning instances copies subnet settings
• Confusing subnet creation with instance launch