Connecting to the EC2 instance using SSH

The main goal of this chapter is to create a simple Hello World web application. Since we are starting with a Vanilla OS, we need to connect to the host to make the necessary changes to turn our standard server into a web server. In order to SSH our instance, we need to find the DNS name of our running instance, as follows:

$ aws ec2 describe-instances \
    --instance-ids i-057e8deb1a4c3f35d \
    --query "Reservations[*].Instances[*].PublicDnsName"

[
    [
        "ec2-34-201-101-26.compute-1.amazonaws.com"
    ]
]      

We now have the public DNS name of our instance and the private key to SSH into it. The last thing to know is that, for the OS that we selected while choosing our AMI in Amazon Linux, the default user account is called ec2-user:

$ ssh -i ~/.ssh/EffectiveDevOpsAWS.pem ec2-user@ ec2-34-201-101-26.compute-1.amazonaws.com

The authenticity of host 'ec2-34-201-101-26.compute-1.amazonaws.com (172.31.22.52)' can't be established.

ECDSA key fingerprint is SHA256:V4kdXmwb5ckyU3hw/E7wkWqbnzX5DQR5zwP1xJXezPU.

ECDSA key fingerprint is MD5:25:49:46:75:85:f1:9d:f5:c0:44:f2:31:cd:e7:55:9f.

Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'ec2-34-201-101-26.compute-1.amazonaws.com,172.31.22.52' (ECDSA) to the list of known hosts.

       __| __|_ )
       _| ( / Amazon Linux AMI
      ___|\___|___|


https://aws.amazon.com/amazon-linux-ami/2018.03-release-notes/

1 package(s) needed for security, out of 2 available

Run "sudo yum update" to apply all updates.
[ec2-user@ip-172-31-22-52 ~]$

If you experience any issues, add the -vvv option in your SSH command to troubleshoot it.