Last week during my session of the Ops&Bytes Terraform boot camp, I ran into an interesting challenge: setting up SSH access to an EC2 instance on my Windows machine using WSL. When I tried to change file permissions for my SSH key (chmod 400 public-instance-key.pem), everything seemed fine until I checked with ls -ltrh – the permissions still showed as -r-xr-xr-x (555), not the expected 400. This caused an issue when trying to SSH into my EC2 instance! 😬

🏗️ Expected Flow

Below is the High Level expect traffic flow

🔍 The Problem

Windows Subsystem for Linux (WSL) doesn’t fully support Unix-style permissions on files stored in Windows directories (/mnt/c/...). This means chmod commands may appear to work, but the permissions aren’t set the way they would be on a native Linux system, which SSH needs for secure connections.

💡 Solution

The fix? Move the SSH key file to a native WSL directory (like ~/) where Linux permissions are properly enforced:

1. Copy the file to your WSL home directory:

    cp /mnt/c/path/to/your/public-instance-key.pem ~/
   

2. Change the permissions to read-only:

    chmod 400 ~/public-instance-key.pem
   

3. Use the key from the WSL directory to SSH into your instance:

    ssh -i ~/public-instance-key.pem your_ec2_user@your_public_ec2_ip
   

👨🏿‍💻 How did I get to the solution?

All it took was a carefully constructed prompt for ChatGpt to explain my issue.

⚠️ Caution

If you're working with WSL and need strict permission settings, always move sensitive files like SSH keys to WSL-native directories. This will save you some headaches and keep things secure! 😊

📚 Resources

• Here is a link to my terraform BootCamp code: https://github.com/Thab310/terraform-bootcamp-week-2

• Slack: https://lnkd.in/dV4sp7GB

• Telegram: https://lnkd.in/d9MSpCEc

Hope this helps others working with Terraform, WSL, and AWS!