Can't connect to an AWS EC2 instance with cURL

Question

Can anyone tell me why can't I connect to an AWS EC2 instance?

I am using cURL to connect like this:

curl ec2-54-xxx-xx-xxx.eu-west-1.compute.amazonaws.com

But I am getting the following error:

curl: (7) couldn't connect to host

Can anyone tell me what might be wrong? I haven't previously worked with AWS.

Answer 1

This could be many things:

1. Review the AWS Security Groups . You probably need to add an incoming traffic exception rule for port 80 in the Security Group that's attached to your instance. For more information refer to the documentation .

2. If your EC2 instance is in a VPC, you need to make sure networking has been set up properly with an Internet Gateway and proper Routing Table rules. For reference, there is a nice example of a typical VPC setup here .

3. Additionally, if the above don't solve the issue, check the EC2 instance's OS firewall rules and that the HTTP server is running.

Answer 2

Check for the firewall on your server which is blocking the connection. Are you able to curl any other website

Answer 3

If you are curling an FTP URL then you may need to set the FTP Passive port range and open the range in your Security group.

Credit: Setting up FTP on Amazon Cloud Server