CODEWITHSUNDEEP
amazon-web-servicesaws-cloudformationamazon-elbamazon-vpc
129
129

Reputation: 3

AWS connect to EC2 through ELB in a VPC, how to configure?

I'm new on AWS and I'm playing around Cloudformation templates to have a working stack. My idea is to have a static hello world html page using EC2 as webserver not reachable from outside but only thorugh ELB (internet-facing). All in a VPC. I've deployed a stack but is still not working, I guess it depends on networking config. How can I set it up?

Starting from examples from awslabs and following Cloudformation docs for each resource, I've made up a yaml template and deployed the stack.

Here is only the EC2 and ELB config

  MYInstance1:
      Type: AWS::EC2::Instance
      Properties:
        DisableApiTermination: 'false'
        InstanceInitiatedShutdownBehavior: stop
        ImageId: ami-70edb016
        InstanceType: t2.micro
        Monitoring: 'false'
        UserData:
          Fn::Base64:
            !Sub |
            #!/bin/bash
            yum update -y
            yum install -y httpd24
            service httpd start
            chkconfig httpd on
            groupadd www
            usermod -a -G www ec2-user
            chown -R root:www /var/www
            chmod 2775 /var/www
            find /var/www -type d -exec chmod 2775 {} +
            find /var/www -type f -exec chmod 0664 {} +
            echo '<html><head><title>Test</title></head><body><p>Hello world!</p></body></html>' > /var/www/html/demo.html
        Tags:
          - Key: environment
            Value: demo-test
        NetworkInterfaces:
        - AssociatePublicIpAddress: 'true'
          DeleteOnTermination: 'true'
          Description: Primary network interface
          DeviceIndex: 0
          SubnetId: !Ref 'PublicSubnetA'
          GroupSet: [!Ref 'MYSGapp']

    MYelb:
      Type: AWS::ElasticLoadBalancing::LoadBalancer
      Properties:
        Subnets: [!Ref 'PublicSubnetB']
        Instances: [!Ref 'MYInstance1']
        SecurityGroups: [!Ref 'MYSGELB']
        Listeners:
        - LoadBalancerPort: '80'
          InstancePort: '80'
          Protocol: HTTP
        HealthCheck:
          HealthyThreshold: '2'
          Interval: '15'
          Target: TCP:443
          Timeout: '5'
          UnhealthyThreshold: '2'

You can find the full template with my current configuration here:

https://pastebin.com/PjDtiwfC

Looking at the console I'm a bit stuck with ACLs and routing.

I expect to be able to see the html page at ELB-Public-DNS.com/demo.html.

More details on where I am now: CloudFormation launch was OK, the server is running. I tried to open all traffic in Ec2 security group inbound rule and EC2 DNS/demo.html actually shows the page. But I need to access to it throug ELB DNS not EC2. From ELB interface I see that the instance is OutOfService as it fails the UnhealthyTreshold. In EC2 security group I've setup inbound rules TCP 80 & 443 from ELB security group but still not working.

Upvotes: 0

Views: 491

Answers (2)

krunal shimpi
krunal shimpi

Reputation: 1

If you're new to cloudformation you can give cloudkast a try. It is an online aws cloudformation template generator. It is very useful for anyone starting out in cloudformation.

Upvotes: 0

Mark B
Mark B

Reputation: 200617

You have configured the load balancer health check to use port 443, but you do not appear to have installed an SSL certificate on your EC2 server. Can you access the HTTPS URL of your EC2 server directly?

You probably want to use the Amazon Certificate Manager service to obtain an SSL certificate and install it on your load balancer, in which case your EC2 server will never have an SSL certificate and will never be listening on port 443, so you need to change the health check port to 80.

Upvotes: 0

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