Note: SSH to EC2 without specifying .pem

To avoid specifying .pem A key file is created each time you connect to an EC2 instance. You can configure the SSH client to automatically use this key by editing the SSH configuration file.

Steps to set up SSH to automatically use keys

1. find your .pem document
   Make sure your private key (.pem files) are stored securely and have the correct permissions:

   chmod 400 /path/to/your-key.pem

1. Edit or create an SSH profile
   Open or create an SSH profile ~/.ssh/config:

   nano ~/.ssh/config

1. Perform individual new configurations for your EC2
   Add an entry for your EC2 instance to the file:

   Host your-ec2-alias
       HostName 
       User ec2-user
       IdentityFile /path/to/your-key.pem

replace:

• your-ec2-alias Give your instance a nickname (for example, my-ec2).
• The public IP or hostname of the individual instance associated with your EC2 execution.
• /path/to/your-key.pem and your full path .pem document.

1. Save and exit
   Save the file and exit the editor (for Nano, press CTRL+O, EnterThen CTRL+X).

2. Test configuration
   Connect using alias without specifying .pem document:

   ssh your-ec2-alias

Example: SSH configuration file

If you have multiple instances, your ~/.ssh/config The file might look like this:

Host my-first-ec2
    HostName 192.0.2.1
    User ec2-user
    IdentityFile /home/username/.ssh/first-key.pem

Host my-second-ec2
    HostName 203.0.113.2
    User ec2-user
    IdentityFile /home/username/.ssh/second-key.pem

Extra tips

• Add a new default key: If most of your EC2 instances use the same key, you can set a global default:

  Host *
      IdentityFile /path/to/default-key.pem

• Avoid permission issues: make sure .pem files and ~/.ssh/config The file can only be read by your user:

  chmod 600 ~/.ssh/config
  chmod 400 /path/to/your-key.pem

After completing this setup, you will not need to specify .pem File manually every time.