Setting Up For 6.101 on GNU/Linux

Table of Contents

• 1) Command Line
• 2) Python
• 3) Text Editor or IDE
• 4) Pytest
• 5) Lab Submission Script
• 5.1) Installing the Submission Script
• 5.2) Configuring SSH Keys
• 5.3) Testing

1) Command Line§

Note that the instructions below (and throughout 6.101) will often refer to using your computer's command line to run programs. We don't expect you to be familiar with using the command line before starting 6.101, and we'll try our best to explain exactly what needs to be done. If you are not familiar with the command line, we suggest reading the section of our course readings about some command-line basics before proceeding.

With time, using the command line will start to feel more comfortable. But it can feel like a lot, especially right away at the start of 6.101! If it feels overwhelming, please don't fret; we're here to help! If you have questions about any of the steps described on this page, please feel free to ask for help, either in person during lab hours or over e-mail at 6.101-help@mit.edu.

2) Python§

6.101 requires you to access Python for completing the lab assignments, and a local Python installation can also be helpful for following along with live sessions, trying things out on your own, etc.

The lab checkers for this class will use Python version 3.11. It is important that you use Python 3.9 or newer, and we strongly recommend that you install and use Python 3.11 (in part because the error messages from Python 3.11 are much better). You can follow the instructions below (which vary depending on your choice of operating system):

From Package Manager

Most major GNU/Linux distributions will have a recent-enough Python available in their repositories, and so it may be possible to install an appropriate Python version from its package manager. If so, it is fine to install from there. For example:

$ sudo apt install python3.11 

On Debian GNU/linux, you can also install IDLE from the idle3 package, e.g.,

$ sudo apt install idle-python3.11 

From Source

It is also possible to compile Python from source if you would prefer to install a more recent version of Python. Below is the sequence of commands necessary to compile Python 3.11.1 on Debian GNU/Linux:

$ sudo apt -y build-dep python3
$ sudo apt -y install build-essential libncurses5-dev libncursesw5-dev libreadline6-dev libdb5.3-dev libgdbm-dev libsqlite3-dev libssl-dev libbz2-dev libexpat1-dev liblzma-dev zlib1g-dev tk-dev uuid-dev libffi-dev
$ wget https://www.python.org/ftp/python/3.11.1/Python-3.11.1.tar.xz
$ tar xvf Python-3.11.1.tar.xz
$ cd Python-3.11.1
$ ./configure --enable-optimizations
$ make
$ sudo make altinstall

These commands first install the software necessary to build Python and then compile and install it. You can test that it worked by running python3 from a command prompt (note that it should report its version as 3.11.1).

3) Text Editor or IDE§

You will also need a program for editing your Python source files. Depending on where you learned Python and how far along you are, you may or may not already have a preferred text editor (or Integrated Development Environment) for working with Python code. If you already have something you are familiar with, feel free to use that! If not, we recommend using the "IDLE" program (which is included with most Python installations) for editing your files.

4) Pytest§

For all labs, you will also need the pytest module installed to run our test cases. Certain labs may have additional requirements (which will be described in the writeups for those labs), but for now, pytest is all we'll need. You can install pytest from the command line using a command like the following:

$ pip3 install pytest

(depending on your setup, you may need to type pip instead of pip3; or you may need to include sudo at the front, i.e. sudo pip3 install pytest)

After having done so, if you make a small Python file containing only the line import pytest, then evaluating that file with Python should work without error.

You should also be able to run pytest from the command line; if not, look for a warning from the pip3 install pytest command of the following form:

WARNING: The scripts py.test and pytest are installed in '...' which is not on PATH.

In this case, you'll want to add the specified directory to your PATH environment variable, or use python3 -m pytest as a workaround.

5) Lab Submission Script§

Throughout 6.101, every time you are ready to submit an assignment to our server to be officially tested and scored, you will run a program from the command line to make that submission.

5.1) Installing the Submission Script§

In order to be able to run the program, we will first need to install it on your machine. You should be able to do so using the following two commands on Debian or Ubuntu (or similar commands on other GNU/Linux distributions):

$ sudo curl -o /usr/local/bin/6.101-submit https://py.mit.edu/_static/spring23/6.101-submit
$ sudo chmod a+rx /usr/local/bin/6.101-submit

You can test whether the installation succeeded by running the following command:

$ 6.101-submit -t

If everything is working, that command should have produced some output, ultimately ending with the message: "labs@py.mit.edu: Permission denied (publickey)." If you see that message, the script was installed successfully!

Note: if you get an error something like "ssh: command not found" then you might need to install an ssh client:

$ sudo apt install -y openssh-client

5.2) Configuring SSH Keys§

The "permission denied" message from the previous step happened because, as of right now, we do not know how to tell that it is you who is running the submission script. In order to be able to tell who you are, we will need one or more "SSH public keys" from you (one for each machine you plan to submit from).

Depending on your previous experience, you may already have one or more SSH keys installed on your machine. You can test for their presence by running the following command:

$ cat ~/.ssh/*.pub

If that command produced any output (typically a line starting with ssh-), you already have an SSH key on your machine! In that case, copy-and-paste the output into this form in order to let us know about this SSH key.

If the command above did not produce any output, that's OK, too; it just means that we'll need to take a few steps to set up a new SSH key. You can do that by running the following command:

$ ssh-keygen -t ed25519

That command should ask you several questions. If you do not have a reason to change your answers to those questions, it should be fine to accept the default values for each (by hitting "Enter" at each question without typing anything). If you do choose a password here, be sure to remember it, as you will need to enter it every time you submit an assignment to the 6.101 server!

Once you have generated a key, rerun the command above (cat ~/.ssh/*.pub) and copy/paste the output into this form.

5.3) Testing§

Once we have your SSH public keys, running the following command should produce slightly different results from before:

$ 6.101-submit -t

Now it should report back your username, as well as your role within 6.101. If you see your username there, you should be all set!