CS 61 Docker

The Docker container-based virtualization service lets you run a minimal CS 61 environment, including a virtual Linux host, on a Mac OS X or Windows host, without the overhead of a full virtual machine solution like VMware Workstation, VMware Fusion, or VirtualBox.

It should be possible to do all CS 61 problem sets on CS 61 Docker.

Advantages of Docker:

• Docker can start and stop virtual machines incredibly quickly.
• Docker-based virtual machines are leaner and take less space on your machine.
• With Docker, you can easily edit your code in your home environment, but compile and run it on a Linux host.

Disadvantages of Docker:

• Docker does not offer a full graphical environment. You will need to run all CS61 programs exclusively in the terminal.
• Docker technology is less user-friendly than virtual machines. You’ll have to type weird commands.
• You won’t get the fun, different feeling of a full Linux desktop.

Preparing CS 61 Docker

To prepare to build your Docker environment:

1. Download and install Docker.

2. Clone a copy of the cs61-lectures repository.

3. Change into the cs61-lectures/docker directory.

To build your Docker environment, run this command. It will take a couple minutes. You’ll want to re-run this command every time the Docker image changes, but later runs should be much faster since they’ll take advantage of your previous work.

$ docker build -t cs61:latest -f Dockerfile .

Running CS 61 Docker by script

Our handout repositories, including cs61-lectures and cs61-psets, contain a cs61-run-docker script that provides good arguments and boots Docker into a view of the current directory. We will update this script throughout the term.

For example:

$ cd ~/cs61-lectures/datarep1
$ echo Hello, Mac OS X
Hello, Mac OS X
$ ls
GNUmakefile     NOTES.md        README.md       add             add.cc          addf.cc
$ ../cs61-run-docker
cs61-user@a47f05ea5085:~/cs61-lectures/datarep1$ echo Hello, Linux
Hello, Linux
cs61-user@a47f05ea5085:~/cs61-lectures/datarep1$ ls
add  add.cc  addf.cc  GNUmakefile  NOTES.md  README.md
cs61-user@a47f05ea5085:~/cs61-lectures/datarep1$ exit
exit
$ 

The script plonks you into a virtual machine! A prompt like cs61-user@a47f05ea5085:~$ means that your terminal is connected to the VM. You can execute any commands you want. To escape from the VM, type Control-D or run the exit command.

The script assumes your Docker container is named cs61:latest, as it was above.

Running CS 61 Docker by hand

If you don’t want to use the script, use a command like the following.

$ docker run -it --rm -v ~/cs61-lectures:/home/cs61-user/cs61-lectures cs61:latest

Explanation:

• docker run tells Docker to start a new virtual machine.
• -it says Docker should run interactively (-i) using a terminal (-t).
• --rm says Docker should remove the virtual machine when it is done.
• -v LOCALDIR:LINUXDUR says Docker should share a directory between your host and the Docker virtual machine. Here, I’ve asked for the host’s ~/cs61-lectures directory to be mapped inside the virtual machine onto the /home/cs61-user/cs61-lectures directory, which is the virtual machine user’s ~/cs61-lectures directory.
• cs61:latest names the Docker image to run (namely, the one you built).

Here’s an example session:

$ docker run -it --rm -v ~/cs61-lectures:/home/cs61-user/cs61-lectures cs61:latest
cs61-user@a15e6c4c8dbe:~$ ls
cs61-lectures
cs61-user@a15e6c4c8dbe:~$ echo "Hello, world"
Hello, world
cs61-user@a15e6c4c8dbe:~$ cs61-docker-version
1
cs61-user@a15e6c4c8dbe:~$ exit
exit
$