Inner SSH Server in Docker Container for X11 Forwarding in a Password-Disabled AWS SSH Server

Inner SSH Server in Docker Container for X11 Forwarding in a Password-Disabled AWS SSH Server

If you are using an AWS SSH server with password authentication disabled, you might encounter difficulties when trying to use X11 forwarding. X11 forwarding allows you to run graphical applications on the server and display them on your local machine. To overcome this limitation, you can set up an inner SSH server within a Docker container. In this article, we will guide you through the process of setting up an inner SSH server for X11 forwarding in a password-disabled AWS SSH server.

Prerequisites

Before we begin, make sure you have the following:

• An AWS SSH server with password authentication disabled
• Docker installed on your local machine

Step 1: Create a Dockerfile

First, create a file named Dockerfile in a new directory on your local machine. Open the file and add the following lines:

FROM ubuntu:latest
RUN apt-get update && apt-get install -y openssh-server
RUN mkdir /var/run/sshd
RUN echo 'root:password' | chpasswd
RUN sed -i 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config
RUN sed -i 's/UsePAM yes/UsePAM no/' /etc/ssh/sshd_config
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]
  

Save the file and exit the text editor.

Step 2: Build the Docker Image

In the same directory where you created the Dockerfile, open a terminal or command prompt and run the following command:

docker build -t inner-ssh-server .
  

This command will build a Docker image named inner-ssh-server based on the instructions in the Dockerfile.

Step 3: Run the Docker Container

Once the Docker image is built, you can run a container from it. Run the following command:

docker run -d -p 2222:22 --name inner-ssh-container inner-ssh-server
  

This command starts a Docker container named inner-ssh-container from the inner-ssh-server image. The container will be accessible on port 2222 of your local machine.

Step 4: Configure SSH Forwarding

Now, you need to configure SSH forwarding to connect to the inner SSH server running inside the Docker container. Open a new terminal or command prompt and run the following command:

ssh -X -p 2222 root@localhost
  

This command establishes an SSH connection to the inner SSH server on port 2222 of your local machine.

Step 5: Test X11 Forwarding

To test X11 forwarding, you can run a graphical application on the inner SSH server and display it on your local machine. For example, run the following command:

xeyes
  

This command will open a simple graphical application called xeyes on your local machine, but it is actually running on the inner SSH server.

Conclusion

By setting up an inner SSH server within a Docker container, you can enable X11 forwarding even on a password-disabled AWS SSH server. This allows you to run graphical applications on the server and display them on your local machine. Follow the steps outlined in this article to easily configure and use X11 forwarding in your AWS SSH server setup.

References