Install an Apache Web-Server on EC2 using IAC

In this tutorial I will give you a guided walk-through on how to install an Apache Web Server on an EC2 Linux Instance using EC2 user data. All resources will be provisioned by CloudFormation (IAC). With that being said, let's get straight into it.

Define our parameters to be used in our CloudFormation Stack.

---
Parameters:
  AppName:
    Type: String
    Description: Enter the name of your resource you are creating.
    Default: ApacheWebServer
  Stage:
    Type: String
    Description: Enter the staging environment of you resource.
    Default: dev

We then define our resources. The resources that we need are, an SSH Key, an EC2 Instance and a Security Group.

Resources:
  ## Our EC2 SSH Key
  SSHKey:
    Type: 'AWS::EC2::KeyPair'
    Properties:
      KeyName: !Join ['-', [!Ref AppName, 'key-pair', !Ref Stage] ]

  ## EC2 Instance    
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-009d6802948d06e52
      InstanceType: t2.micro
      KeyName: !Ref SSHKey
      SecurityGroups:
        - !Ref SSHSecurityGroup
      # we install our web server with user data
      UserData: 
        Fn::Base64: |
          #!/bin/bash -xe
          yum update -y
          yum install -y httpd
          systemctl start httpd
          systemctl enable httpd
          echo "Hello World from user data" > /var/www/html/index.html
      Tags:
        - Key: Name
          Value: !Ref AppName
        - Key: Environment
          Value: !Ref Stage


  # Our EC2 security group
  SSHSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: SSH and HTTP
      SecurityGroupIngress:
      - CidrIp: 0.0.0.0/0
        FromPort: 22
        IpProtocol: tcp
        ToPort: 22
      - CidrIp: 0.0.0.0/0
        FromPort: 80
        IpProtocol: tcp
        ToPort: 80

Note: The key take away here is the block of code we wrote for user data. We are using "Fn::Base64" followed by a vertical pipe to pass an entire bash script to the instance. The vertical pipe is used so the script can be recognized as one string.

Complete Template File

---
Parameters:
  AppName:
    Type: String
    Description: Enter the name of your resource you are creating.
    Default: ApacheWebServer
  Stage:
    Type: String
    Description: Enter the staging environment of you resource.
    Default: dev

Resources:
  ## Our EC2 SSH Key
  SSHKey:
    Type: 'AWS::EC2::KeyPair'
    Properties:
      KeyName: !Join ['-', [!Ref AppName, 'key-pair', !Ref Stage] ]

  ## EC2 Instance    
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-009d6802948d06e52
      InstanceType: t2.micro
      KeyName: !Ref SSHKey
      SecurityGroups:
        - !Ref SSHSecurityGroup
      # we install our web server with user data
      UserData: 
        Fn::Base64: |
          #!/bin/bash -xe
          yum update -y
          yum install -y httpd
          systemctl start httpd
          systemctl enable httpd
          echo "Hello World from user data" > /var/www/html/index.html
      Tags:
        - Key: Name
          Value: !Ref AppName
        - Key: Environment
          Value: !Ref Stage


  # Our EC2 security group
  SSHSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: SSH and HTTP
      SecurityGroupIngress:
      - CidrIp: 0.0.0.0/0
        FromPort: 22
        IpProtocol: tcp
        ToPort: 22
      - CidrIp: 0.0.0.0/0
        FromPort: 80
        IpProtocol: tcp
        ToPort: 80

Upload CloudFormation Stack to the console.

First, navigate to the directory where you have your template file stored. You can use the below terminal command to upload your stack to AWS.

aws cloudformation deploy 
  --template-file <TEMPLATE NAME> 
  --stack-name <STACK NAME> 
  --profile <AWS PROFILE NAME>

If the stack was uploaded successfully, you should see this message "Successfully created/updated stack - ".

Navigate to AWS Console

If you are in the console, go to EC2 Dashboard, you should see the instance you created. Select the instance and click on connect. Connect to the instance using EC2 Instance Connect.

Inspect Cloud Init Logs

Now we are going to inspect the logs to view the scripts that ran when the instance was booted up.

First, we need root privileges. Execute the following command so we can have root privileges in our instance.

sudo su 

Second, we're gonna run the command to view the actual log files.

 cat /var/log/cloud-init-output.log

Now you should be able to see a complete list of logs from the scripts that were executed.

Lastly, to test that our web server is properly hosting our html web page. You can copy the public DNS of the instance, paste it in your web browser. By doing this you should be able to access the web page we created.

That's it, we successfully provisioned an EC2 instance and installed an Apache Web Server on it using user-data. Now, the last step is to clean up all the resources that were used.

Clean Up Resources
In your terminal execute the following command. Since, we created our resources using CloudFormation by deleting the stack, all resources that were in the stack will be deleted as well.

aws cloudformation delete-stack 
 --stack-name <STACK NAME>

This was just a small demonstration of what you can accomplish with EC2 user data. Please feel free to explore beyond this tutorial and add extra features.

I do hope this tutorial was useful for you. Stay curious, keep learning, and keep building. Thank you.