AWS CloudFormation Introduction

CloudFormation is a declairative way of outlining your AWS infrastructure for any resources (most of them are supported!).

For example with a cloud example you can say:

• I want a security group
• I want 2 EC2 instances using this security group
• I want an S3 Bucket
• I want a Load Balancer (ELB) in front of these resources.

Then cloudformation creates those things for you in the right order with the exact configuration that you specify!

• No resources are manually created, which is excellent for control.
• Changes to infrastructure are reveled through code.

• Each resource within your stack is tagged with an identifier so you can easily see how much a stack costs to you!
• We can easily estimate the cost of your resources using the cloud formation template.
• Saving Strategy: In some enviornment you automate deletion of templates at 5:00pm & recreate at 8:00AM safely.

• Ability to destroy & recreate an infrastructure on the cloud on the fly.
• Automated generation of diagram for your templates.
• Declarative programming (No need to figure out ordering & orchestration)

• Leverage existing templates to the web.
• Leverage the documentation

• Everything we will see in the course is supported.
• You can use custom resources, for the resources that aren’t supported.

CloudFormation Stack Designer

• Design IaaC using GUI & Images
• We can see all the resources
• We can see the relationship between components.

For example :

# o-just-ec2.yaml file
Parameters:
	SecurityGroupDescription:
		Description: "Security group lorem ipsum other text"
		Type: String

Resources:
	MyInstance:
		Type: AWS::EC2::Instance
		properties:
			AvailablityZones: us-east-1a
			ImageId: ami-a4c7edb2
			InstanceType: t2.micro
			SecurityGroups:
				- !Ref SSHSecurityGroup
				- !Ref ServerSecurityGroup
	# An Elastic IP For our instance
	MyEIP:
		Type: AWS::EC2::EIP
		Properties:
			InstanceId: !Ref MyInstance
	# Our EC2 Security Group
	SSHSecurityGroup:
		Type: AWS::EC2::SecurityGroup
		Properties:
			GroupDescription: "Enable SSH access via ort 22"
			SecurityGroupIngress:
				- CidrIP: 0.0.0.0/0
				- FromPort: 22
				- IpProtocol: TCP
				- ToPort: 22
	# Our Second EC2 Security Group
	ServerSecurityGroup:
		Type: AWS::EC2::SecurityGroup
		Properties:
			GroupDescription: "Security Grp"
			SecurityGroupIngress:
				- IpProtocol: TCP
				FromPort: 80
				ToPort: 80
				CidrIP: 0.0.0.0/0
				- IpProtocol: TCP
				FromPort: 22
				ToPort: 22
				#your localmachine IP For SSH
				CidrIP: 192.168.1.1/32
# This section will print out allocated Elastic IP!
Outputs:
	ElasticIP:
		Description: ElasticIP Value
		Value: !Ref MyEIP