How to Add SSH on an Existing Google Compute Engine

Adding SSH to an existing Google Compute Engine instance can be daunting, especially for those new to the Google Cloud Platform.

However, it is an essential step in accessing and managing your instance, as SSH allows you to connect securely to your virtual machine and execute commands remotely.

This article will walk you through add SSH on an existing Google Compute Engine instance.

We will cover everything from generating SSH keys to adding them to your instance using the Google Cloud Console. So, let’s get started!

Add SSH on an Existing Google Compute Engine

Step 1: Generate Your SSH Key Pair

Before you can add SSH to your existing Google Compute Engine instance, you need to generate your SSH key pair.

Your SSH key pair consists of a private key that you keep on your local machine and a public key that you add to your virtual machine.

The private key is used to authenticate you when you connect to your instance, while the public key is used to authorize you to access your instance.

You can use the terminal on your local machine to generate your SSH key pair. Open your terminal and type the following command:

ssh-keygen -t rsa -f ~/.ssh/my-ssh-key

This command generates an RSA key pair named “my-ssh-key” in the “~/.ssh” directory. You can choose a different name and directory if you prefer.

Step 2: Add Your Public SSH Key to Your Instance

Now that you have generated your SSH key pair, you must add your public key to your Google Compute Engine instance. You can do this using the Google Cloud Console.

First, navigate to the VM instances page in the Google Cloud Console. Find the instance you want to add SSH to and click the “Edit” button.

In the “Edit” panel, scroll down to the “SSH Keys” section and click on the “Add item” button. Paste your SSH key in the “Public key” text box. You can find your public key by typing the following command in your terminal:

cat ~/.ssh/my-ssh-key.pub

Replace “my-ssh-key” with the name of your key pair.

After you have pasted in your public SSH key, click on the “Save” button to save your changes. Your public SSH key is now added to your instance.

Step 3: Connect to Your Instance Using SSH

Now that you have added your public SSH key to your instance, you can connect to your instance using SSH. To do this, you need to know the internal IP address of your instance.

You can find the internal IP address of your instance in the Google Cloud Console. Navigate to the VM instances page and click on the name of your instance.

In the “Details” panel, you can find the internal IP address under the “Network interfaces” section.

To connect to your instance using SSH, open your terminal and type the following command:

ssh -i ~/.ssh/my-ssh-key [USERNAME]@[INTERNAL_IP_ADDRESS]

Replace “my-ssh-key” with the name of your key pair, “[USERNAME]” with your username, and “[INTERNAL_IP_ADDRESS]” with the internal IP address of your instance.

Using Windows, you can use a tool like PuTTY to connect to your instance using SSH.

Step 4: Troubleshooting SSH Connection Issues

If you are having trouble connecting to your instance using SSH, there are a few things you can try:

• Check that your public SSH key is added to your instance correctly. You can do this by navigating to the VM instances page in the Google Cloud Console and clicking on the name of your instance. In the “Details” panel, scroll down to the “SSH Keys” section and make sure your public key is listed.
• Check that your private SSH key is in the correct directory on your local machine and has the correct permissions. Your private key should be in the “~/.ssh” directory and have permission to “600”. You can check the permissions of your private key by typing the following command in your terminal: ls -l ~/.ssh/my-ssh-key
• Replace “my-ssh-key” with the name of your key pair.
• Check that your firewall rules are configured correctly. If you cannot connect to your instance using SSH, it could be because your firewall rules are blocking the SSH traffic. You can check your firewall rules in the Google Cloud Console by navigating to the “Firewall rules” page.
• Check that your SSH agent is running. If you use an SSH agent to manage your SSH keys, ensure it runs and that your key is added to the agent. You can check if your agent is running by typing the following command in your terminal: eval “$(ssh-agent -s).”

This command starts the SSH agent and outputs the agent’s environment variables.

Conclusion

Adding SSH to an existing Google Compute Engine instance is crucial in managing and accessing your virtual machine.

Following the steps outlined in this article, you can generate your SSH key pair, add your public key to your instance using the Google Cloud Console, and connect to your instance using SSH.

Remember to check your firewall rules, ensure your SSH agent is running, and that your private key has the correct permissions before connecting to your instance.

If you encounter any issues, various resources are available to help you troubleshoot and resolve the problem. The cloud.google.com documentation is an excellent resource for step-by-step instructions and troubleshooting tips.

Additionally, the Google Cloud Platform has a support team you can contact if you encounter any issues you cannot resolve.

In conclusion, adding SSH to an existing Google Compute Engine instance is a simple but crucial step in managing and accessing your virtual machine.

Following the steps outlined in this article and using the Google Cloud Console, you can quickly and easily generate your SSH key pair, add your public key to your instance, and connect to your instance using SSH.