NTHU Operating Systems Tutorials

Set Up VPN connection

For security reasons, our server must be accessed via SSH. Below is an example of how to connect to our course VPN:

VPN connection steps

1. Download wireguard.
2. Open WireGuard and select "Import tunnel from file."
3. Choose the .conf file provided in the TA's email.
4. Click "Activate" to connect.

Introduction

Having a nice ssh setting makes connection to server much more easier. Originally, connecting to server requires the following steps

1. Run ssh command with username and ip address specified

   ssh os24team99@192.168.5.2

2. Enter password

But with ssh config and authorized_keys, you can connect to the server with just a short command, for example

ssh nachos

Besides, you can also use Visual Studio Code to connect to the server with just a click after configuring ssh config.

Terminology

• Client: The machine you are using to connect to the server, for example your laptop.
• Server: The machine you are connecting to, for example the server provided by the course.
• To run a command on the client means to run the command on your PC terminal.
• To run a command on the server means to ssh to the server and run the command on the server terminal.

SSH Config - To simplify the connection

1. Open terminal (Client)

2. Run the following command to create a new ssh config file and open it (Client)

   # For MacOS
   touch ~/.ssh/config
   open ~/.ssh/config
   # For Windows cmd
   notepad %userprofile%\.ssh\config
   # For Windows powershell
   notepad $env:userprofile\.ssh\config

3. Add the following content to the file. (Replace os24team99 with your username) (Client)

   Host nachos
       HostName 192.168.5.2
       user os24team99

4. Save and close the file

5. Then you can connect to the server with the following command (Client)

   ssh nachos

SSH Key - To log in without password

1. Open terminal (Client)

2. Run the following command to generate a new ssh key (Client)

   ssh-keygen

3. Copy your public key (Client)

   # For MacOS
   ssh-copy-id nachos
   # For Windows cmd
   type %userprofile%\.ssh\id_rsa.pub | ssh nachos "cat >> ~/.ssh/authorized_keys"
   # For Windows powershell
   Get-Content $env:userprofile\.ssh\id_rsa.pub | ssh nachos "cat >> ~/.ssh/authorized_keys"

4. Now you can connect to the server without entering password (Client)

   ssh nachos

Visual Studio Code - To connect to server with just a click

You can choose to use mobaxterm in Windows, but you can also use vscode, a much more convenient choice.

1. Install Remote - SSH extension in vscode link

   

2. Click on the icon at the left

   

3. Connect to host

   

Congratulations! Now you can connect to the server with just a click.

Working on Nachos

Copy Nachos to your user directory

1. Connect to the server

2. Copy the nachos folder to your home directory (Server)

   cp -r /home/os2024/share/NachOS-4.0_MP1 .

Open Nachos in Visual Studio Code

1. Connect to the server with vscode
2. Hit cmd+o for MacOS or ctrl+k ctrl+o for Windows, type /home/os2024/os24team99/NachOS-4.0_MP1/code and click ok
3. Now you can edit the nachos code in vscode

Git

We have already set up git in the NachOS-4.0_MP1 folder. It is recommended to use git to manage your code.

Some useful git commands:

• Create a commit

  git add .
  git commit -m "Your commit message"

• Push your code to the remote repository if you have added your remote repository

  git push

Trace Code Tools and Configuration

It is recommended to install the extension C/C++, and Makefile tools, and set up the file NachOS-4.0_MP1/code/.vscode/c_cpp_properties.json (We have already set up this file for you)

{
    "configurations": [
        {
            "name": "Linux",
            "intelliSenseMode": "gcc-x64",
            "includePath": [
                "${workspaceRoot}",
                "${workspaceRoot}/filesys",
                "${workspaceRoot}/lib",
                "${workspaceRoot}/machine",
                "${workspaceRoot}/network",
                "${workspaceRoot}/test",
                "${workspaceRoot}/threads",
                "${workspaceRoot}/userprog"
            ],
            "compilerPath": "/usr/bin/gcc",
            "defines": [
                "FILESYS_STUB", // Comment in MP4
                "RDATA",
                "SIM_FIX",
                "CHANGED",
                "LINUX",
                "x86"
            ],
            "configurationProvider": "ms-vscode.makefile-tools"
        }
    ],
    "version": 4
}

This file is used to provide intellisense for vscode, so that you can have code completion and go to definition.

There are also convenient shortcuts to use in vscode.

• keyboard-shortcuts-macos
• keyboard-shortcuts-windows

To build and run nachos

Build nachos

# Build test programs
# in code/test directory
make clean
make add
# Example to run a test
../build.linux/nachos -e add

# Build test programs
# in code/test directory
make clean
make add
# Example to run a test
../build.linux/nachos -e add

Run Nachos on your local machine with Docker

What is Docker?

Docker is an open platform for developing, shipping, and running applications. Docker enables you to separate your applications from your infrastructure so you can deliver software quickly. With Docker, you can manage your infrastructure in the same ways you manage your applications. By taking advantage of Docker's methodologies for shipping, testing, and deploying code, you can significantly reduce the delay between writing code and running it in production. Docker

Why use Docker?

• You can run the same environment on your local machine as the server, without installing the dependencies on your local machine.
• To stop relying on network connection to the server, and prevent power cut (which happens a lot recently).

Pre-requisites (Windows)

1. Install WSL2 link

   wsl --install

2. Install a Linux distribution from Microsoft Store, for example Ubuntu and setup your username and password

   wsl --install -d Ubuntu

3. (Optional) Use WSL2 as the default version for better performance

   wsl --set-default-version 2
   wsl --set-version Ubuntu 2

4. Install Docker Desktop link

5. Enable WSL2 integration for your linux distribution in Docker Desktop

   

6. Start wsl

   wsl

7. Make sure docker is running in wsl

   docker --version

8. (Important) Do not be under /mnt/ directory when performing the following steps, , as it will cause issues. If you are not sure, run the following command to go to your home directory

   cd ~

9. Download NachOS-4.0_MP1 from your github repository or copy from the server to your directory, and you can start building and running nachos in the docker container.

Pre-requisites (MacOS)

1. Install Docker link
2. Download NachOS-4.0_MP1 from your github repository or copy from the server to your directory, and you can start building and running nachos in the docker container.

Instructions

1. Install Docker link

2. Download NachOS-4.0_MP1 from your github repository or copy from the server.

3. Run the following command to build the docker image (Client)

   cd NachOS-4.0_MP1
   make build # to build the image yourself
   # or
   make pull # to pull the built image from docker hub

4. Run the following command to start and get into the docker container (Client)

   make run

5. Now you are in the docker container under code/test

6. Now you can build and run nachos in the docker container (Docker)

   bash build_nachos.sh -j
   # or clean and build
   bash build_nachos.sh -cj
   # or clean and build without showing make outputs
   bash build_nachos.sh -cqj

7. To run a test program (Docker)

   # Build test programs
   # in code/test directory
   make clean
   make add
   # Example to run a test
   ../build.linux/nachos -e add

8. To exit the docker container, run the following command (Docker)

   exit