TheJobScraperCFN.yaml

# W.I.P. CloudFormation template 

AWSTemplateFormatVersion: '2010-09-09'
Description: Creates all the needed resources to run the job scraper
Outputs:
  SSHPrivateKeyARN:
    Description: The ARN of the SSM parameter storing the private key
    Value: !Sub 'arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/jobscraper/privatekey' 

Resources:
  # IAM Role for Lambda
  PowerCycleLambdaRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: sts:AssumeRole
      Policies:
        - PolicyName: EC2PowerCyclePolicy
          PolicyDocument:
            Version: '2012-10-17'
            Statement:
              - Effect: Allow
                Action:
                  - 'ec2:StopInstances'
                  - 'ec2:StartInstances'
                  - 'ec2:DescribeInstanceStatus'
                Resource: !GetAtt JobScraperInstance.Arn  

  # EC2 Instance  
  JobScraperInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0149b2da6ceec4bb0 # Ubuntu 22.04
      InstanceType: t2.medium
      KeyName: !Ref EC2KeyPair
      UserData:
        Fn::Base64: "echo 'hello world'" # TO:DO replace this with the curl command that gets the setup.sh. Also modify the setup.sh script to handle environment variables so that http flask is not run as root.
      NetworkInterfaces:
        - AssociatePublicIpAddress: true 
          DeviceIndex: 0
          SubnetId: !Select [ 0, !GetAZs '' ]
          GroupSet: 
            - !Ref JobScraperSecurityGroup

  # SSH Key Pair  
  EC2KeyPair:
    Type: AWS::EC2::KeyPair
    Properties:
      KeyName: JobScraperKeyPair  

  # Security Group 
  JobScraperSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow SSH and HTTP/HTTPS 
      VpcId: !Ref 'VPC' # TO:DO make this reference the default VPC and or just create a basic one
      SecurityGroupIngress: 
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: your-ip-address/32  # TO:DO make this an input variable
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 443
          ToPort: 443
          CidrIp: 0.0.0.0/0

  # Parameter to Store Private Key
  PrivateKeyParameter:
     Type: AWS::SSM::Parameter
     Name: /jobscraper/privatekey  
     Type: String
     Value: !Ref EC2KeyPair

  # Lambda Function that power cycles our EC2 instance once a day in order to get a new IP and ensure no zombie processes are on the loose 
  PowerCycleLambda:
    Type: AWS::Lambda::Function
    Properties:
      Handler: index.handler 
      Runtime: python3.9 
      Role: !GetAtt PowerCycleLambdaRole.Arn
      Timeout: 180 
      Code: 
        ZipFile: |
          import boto3
          import time
          ec2_client = boto3.client('ec2', region_name='us-east-1')
          def handler(event, context):
              instance_id = event['instanceId']
              try:
                  # Stop the instance
                  ec2_client.stop_instances(InstanceIds=[instance_id])
                  print('Stopping instance')
                  # Wait for the instance to be fully stopped
                  params = {'InstanceIds': [instance_id], 'IncludeAllInstances': True}
                  while True:
                      response = ec2_client.describe_instance_status(**params)
                      if response['InstanceStatuses'] and response['InstanceStatuses'][0]['InstanceState']['Name'] == 'stopped':
                          break
                      else:
                          print('Instance not yet stopped, waiting...')
                          time.sleep(5)  # Wait 5 seconds
                  print('Instance stopped')
                  # Start the instance
                  ec2_client.start_instances(InstanceIds=[instance_id])
                  print('Instance started')
              except Exception as error:
                  print(error)

  PowerCycleSchedule:
    Type: AWS::Events::Rule
    Properties:
      ScheduleExpression: cron(0 15 ? * MON-SUN *)
      State: ENABLED
      Targets:
        - Arn: !GetAtt PowerCycleLambda.Arn
          Id: 'PowerCycleTarget'
          Input: '{"instanceId": "!REF JobScraperInstance"}' # TO:DO make this reference the instance id of the JobScraperInstance correctly