Appliance

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The CS50 Appliance (aka "CS50 in a Box") is a virtual machine (VM) that lets anyone on the Internet (like you!) tackle the problem sets at cs50.tv, even if they're not students at Harvard.

It's based on Ubuntu JeOS, "an efficient variant of the Ubuntu Server operating system, configured specifically for virtual appliances." It is an appliance in the sense that we've preconfigured this VM for a specific purpose: enabling folks (like you!) to tackle CS50's problem sets.

In other words, if you don't have an account on nice.fas.harvard.edu or cloud.cs50.net (because you're not a student in CS50), you can still play along at home. The CS50 Appliance will let you compile source code from lectures and implement problem sets without having to figure out how to configure GCC, etc. yourself. Having the CS50 Appliance on your computer is like having your own, local version of nice.fas.harvard.edu and cloud.cs50.net! Put another way, the CS50 Appliance lets you run (Ubuntu) Linux inside of a window on your own computer, even if you're already running (some other version of) Linux, Mac OS, Solaris, or Windows!

Make sense? (If not, you may want to watch, at least, Week 0's and Week 1's lectures. :-)

Incidentally, this appliance is a work in progress, so please forgive any bugs! We've documented known issues down below. Do turn to the course's Google Group if you run into problems, and we'll do our best to improve the experience.

Contents

Instructions

show summary »

How to Install Appliance

  1. To use CS50 in a Box, you'll first need to install VirtualBox 3.2.6, a free program (known as a hypervisor) from Oracle (formerly Sun Microsystems) that will let you run virtual machines on your own computer, whether you run Linux, Mac OS, Solaris, or Windows. Go ahead and download the version for your OS from http://www.virtualbox.org/wiki/Downloads. Then install it. (If you run into trouble, there's a video that might help. On Windows, you may need to click Install, OK, or the like one or more times if prompted, and if the installer appears to hang, try dragging the installer's window to the side to see if there's a dialogue waiting for your input hidden behind it.)
  2. Next, download the latest CS50 Appliance at http://cdn.cs50.net/2009/fall/vms/cs50-1.4.zip. Then unzip it.
  3. Finally, launch VirtualBox (as by clicking its icon wherever you installed it). Select Import Appliance... from VirtualBox's File menu. Click Choose. Navigate your way to that unzipped cs50-1.4 folder, highlight the cs50-1.4.ovf file within, and click Open. Then click Next. You should see a summary of the appliance's settings. Click Import. Then click Agree if you agree with the license. Within a few seconds or minutes, you should see CS50 in a Box 1.4 in VirtualBox's left-hand menu. Highlight it, then click Start.

OMG, you just booted your own copy of Ubuntu Linux.

How to Use Appliance

The first thing you should see when the appliance boots up is a login screen. Hit Enter or click John Harvard's name. (Oh, henceforth, you are John Harvard. Your initial password is crimson. And here's what you look like.) When prompted for a password, type your password, then hit Enter or click Log In. After a few seconds, you should see your desktop. Even though you may think of Linux as having only a command-line interface, graphical user interfaces do exist. We've installed GNOME, one of the most popular, for you. However, we installed as few programs as possible to keep the appliance small. You're welcome to install additional programs via System → Administration → Add/Remove Applications.

How to Change Name

As much as you might not like being called John, allow us to suggest that you not change your name (or username) yet. Life will be simpler as John.

How to Change Password

Select System → Preferences → About Me, then click Change Password.... Or, open a terminal and execute passwd at the prompt.

With that said, allow us to suggest that you not change your password yet. (Life will be simpler with crimson.) The appliance has been configured in such a way that only someone with access to your computer (e.g., you) can access the appliance. Even though the appliance can connect to the Internet, the Internet cannot connect to the appliance.

How to Change Language

If English is not your native language, you may want to change the appliance's default language. Some things will remain in English, but you might find yourself more at home nonetheless. Select System → Administration → Language Support. Click OK if prompted to download additional languages. Then click Install/Remove Languages, click the box next to your preferred language, then click Apply Changes. Click OK if prompted. Then select your language from the menus beneath For my menus and windows and For everyone at startup and login. Then close the window and select → Restart... from the appliance's top-right corner.

How to Change Keyboard Layout

If you have a non-U.S. (or non-standard) keyboard, you may want (or need!) to change your keyboard's layout. Select System → Preferences → Keyboard. Then click the Layouts tab and configure as desired.

How to Change Timezone

If you don't live in Cambridge, Massachusetts, USA, you may want to change the appliance's timezone. Select System → Administration → Time and Date. To unlock the window that appears, you may need to click the keys next to Click to make changes. Enter your password if prompted. Then make any changes you'd like.

How to Open a Terminal

Select Applications → Accessories → Terminal (or simply right-click anywhere on your desktop and select Open in Terminal). Ta da! You should see a command-line interface much like the one you've probably seen in lectures! It's at this blinking prompt that you'll be able to type commands like cd, gcc, ls, and nano, as discussed in lectures and problem sets.

When a problem set tells you to "ssh to nice.fas.harvard.edu" or "ssh to cloud.cs50.net", you can simply open a terminal instead (or you can SSH to the appliance).

Just realize that when you open a terminal by right-clicking your desktop, you'll start in your ~/Desktop/ directory instead of your home directory (i.e., ~).

How to SSH to Appliance

If you'd like to SSH to the appliance from your own computer (as with Terminal on Mac OS or with PuTTY on Windows), you can SSH from your computer to 192.168.56.50, which is the appliance's static IP address. (The appliance actually has a second IP address, obtained via DHCP, but it uses that IP to access the Internet.)

If you'd instead like to SSH from the appliance to your computer (assuming your computer is running an SSH server), you can SSH from the appliance to 192.168.56.1, which is the static IP address that VirtualBox has secretly assigned to your computer.

How to Release Keyboard and Mouse

Once you click inside of the appliance, it "captures" (i.e., "owns") your keyboard's keystrokes and your mouse's movements. To release your keyboard and mouse from the appliance's clutches, hit VirtualBox's "host key": on a Mac, VirtualBox's host key is your keyboard's left-Command key; on any other OS, VirtualBox's host key is your keyboard's right-Control key. Once you hit that key, should be able to move your mouse anywhere on your screen.

How to Install Guest Additions

"Guest additions" are device drivers and system applications that come with VirtualBox that can improve the performance and usability of the CS50 Appliance. Not only will those additions allow you to change the appliance's resolution and enter/exit seamless mode, they may also eliminate the need to "release" your keyboard and mouse via VirtualBox's "host key."

To install them, select Install Guest Additions... from VirtualBox's Devices menu while the appliance is running. (This menu is outside of the appliance, not inside of it. You may need to release your keyboard and mouse first.) Then open a terminal and execute the commands below. Input your password if prompted. (For security, you will not see your password as you type it.) 

sudo su -
aptitude install dkms
mount /dev/cdrom /mnt
/mnt/VBoxLinuxAdditions-x86.run

Once the software has been installed, execute the command below: 

umount /mnt

Then select CD/DVD Devices → Unmount CD/DVD Device from VirtualBox's Devices menu. (This menu is outside of the appliance, not inside of it. You may need to release your keyboard and mouse first.) Then reboot the appliance by selecting → Restart... in the appliance's top-right corner.

How to Change Resolution

By default, the appliance's resolution is 800 x 600, but, odds are, your own screen's resolution is higher. But if you try to make VirtualBox's window bigger, the appliance itself won't grow. At least not yet! You'll first need to install guest additions if you haven't already. Then you'll be able to click and drag the appliance's bottom-right corner to resize it.

How to Enter/Exit Fullscreen Mode

For fullscreen mode to work (well), you'll first need to install guest additions if you haven't already.

To enter fullscreen mode thereafter, select Fullscreen Mode ... from VirtualBox's Machine menu while the appliance is running. (This menu is outside of the appliance, not inside of it.) Or hit VirtualBox's "host key" and F together: on a Mac, VirtualBox's host key is your keyboard's left-Command key; on any other OS, VirtualBox's host key is your keyboard's right-Control key.

To exit fullscreen mode, hit VirtualBox's "host key" and F together again.

How to Enter/Exit Seamless Mode

Seamless mode lets you "extract" windows (e.g., a Terminal window) from the CS50 Appliance and position them right alongside your computer's own windows; in seamless mode, the appliance's windows are no longer confined to the appliance's own rectangular window.

For seamless mode to work, you'll first need to increase the appliance's video memory. With the appliance powered off, highlight CS50 in a Box 1.4 in VirtualBox's list of VMs, then click Settings. Click Display. Then ensure that Video Memory is at least 17 MB. Then click OK, start the appliance, and proceed to install install guest additions if you haven't already.

To enable seamless mode thereafter, hit VirtualBox's "host key" and L together: on a Mac, VirtualBox's host key is your keyboard's left-Command key; on any other OS, VirtualBox's host key is your keyboard's right-Control key.

To exit seamless mode, hit VirtualBox's "host key" and L together again.

How to Use phpMyAdmin

Visit http://192.168.56.50/phpmyadmin/ using Firefox within the appliance or using your own computer's browser. You will automatically be logged in as John Harvard for whom we have created two databases (jharvard_pset7 and jharvard_pset8) by default; you are welcome to create others.

How to Transfer Files between Appliance and Your Computer

If you'd like to SFTP to the appliance from your own computer (as with Cyberduck on Mac OS or with WinSCP on Windows), you can SFTP from your computer to 192.168.56.50, which is the appliance's static IP address. (The appliance actually has a second IP address, obtained via DHCP, but it uses that IP to access the Internet.)

Alternatively, you can create a "shared folder" on your own computer's hard drive that the CS50 Appliance can access directly, thereby allowing you to share files between your computer and the appliance without having to use SFTP.

To create a shared folder, select Shared Folders... from VirtualBox's Devices menu while the appliance is running. (This menu is outside of the appliance, not inside of it. You may need to release your keyboard and mouse first.) In the window that appears, click the little folder icon with a plus (+) sign. In the Add Share window that appears, click the downward-pointing arrow next to Folder Path and select Other.... Navigate your way to a folder on your own hard drive that you'd like to share with the appliance, creating a new folder if desired; once you've selected that folder, click Choose. (For simplicity, select a folder whose name is entirely alphanumeric; don't select a folder with spaces or punctuation in its name. If you create a new folder, you may need to highlight some other file or folder after creating it, then re-highlight that new folder in order for the Choose button to work.) In the Add Share window, be sure that the folder you selected now appears next to Folder Path. Next to Folder Name, confirm that the name does not have any spaces or punctuation; remember this name. Click OK. You should now see your choice of shared folders in the Shared Folders window. Then click OK.

Next, open a terminal and execute these commands, where sharename is the name of your shared folder: 

mkdir ~/Desktop/sharename/
sudo modprobe vboxsf
sudo mount -t vboxsf -o uid=1000,gid=1000 sharename ~/Desktop/sharename/

Because these commands require superuser privileges, you may be prompted to provide your password. (For security, you will not see your password as you type it.)

Your shared folder should now be "mounted" inside of the appliance right on your desktop. To confirm, create a file inside of that shared folder on your own computer (e.g., drag some file from your desktop into that folder). Then double-click the mounted folder on the appliance's desktop. That same file should be listed.

Next create a file inside of that shared from within the appliance by executing a command like this one: 

touch ~/Desktop/sharename/foo

Then open that shared folder on your own computer. You should see both foo and whatever other file you put there.

At this point, you can transfer files between the appliance and your own computer by way of that folder.

To unmount (i.e., unshare) that folder, you can execute this command: 

sudo umount ~/Desktop/sharename/

If you'd like this shared folder to be permanent (and exist every time you boot the appliance), select Shared Folders... from VirtualBox's Devices menu while the appliance is running. Highlight the shared folder. Click the little folder icon with a circle (below the little folder icon with a plus (+) sign and above the little folder icon with a minus (-) sign). Check Make Permanent in the Edit Share window that appears, then click OK. Confirm that your shared folder is now under Machine Folders instead of Transient Folders, then click OK. Next, open a terminal and execute this command: 

sudo nano /etc/fstab

Add this line to the bottom of that file, taking care not to change anything else: 

sharename /home/jharvard/Desktop/sharename/ vboxsf uid=1000,gid=1000 0 0

Save the file by hitting Ctrl-x followed by y. Then restart the appliance to confirm that the shared folder gets mounted automatically at startup. Note that /home/jharvard/Desktop/sharename/ (aka ~/Desktop/sharename/) must exist; the shared folder's contents get mounted inside of that directory.

How to Shut Down

Select → Shut Down... in the appliance's top-right corner.

How to Compile Source Code from Lectures

To compile some lecture's source code, figure out the URL of the file you'd like to download, as by browsing the "index" for some lecture's source code (e.g., http://cdn.cs50.net/2009/fall/lectures/1/src/). Then download that URL (e.g., http://cdn.cs50.net/2009/fall/lectures/1/src/hai1.c) with this command: 

wget http://cdn.cs50.net/2009/fall/lectures/1/src/hai1.c

Odds are you can then compile the file with: 

gcc hai1.c

And you can then run the program with this command: 

a.out

Caveats

  • Some source code might require tweaks to get it to compile inside of the appliance. If you run into a compilation error, simply turn to the course's Google Group for assistance!

How to Do Problem Sets

You'll first want to install the CS50 Appliance. Then you'll want to download and read the problem set's PDF, which is available at cs50.tv. Perhaps needless to say, ignore any sentences that appear to be intended only for CS50's own students. You'll notice that most problem sets instruct you to "SSH to nice.fas.harvard.edu" or "SSH to cloud.cs50.net". If you're not a CS50 student, you won't have an account on either server, but that's what the CS50 Appliance is for! Anytime you're told to SSH to nice.fas.harvard.edu or cloud.cs50.net, instead just open a terminal or SSH to your appliance.

Anyhow, for problem sets that come with distros (i.e., source code), figure out the URL of the source code's ZIP (e.g., http://cdn.cs50.net/2009/fall/psets/3/pset3.zip), as by right-clicking or Ctrl-clicking the link at cs50.tv and selecting Copy Link or the like. Then launch the appliance, open a terminal, and execute a command like the below: 

wget http://cdn.cs50.net/2009/fall/psets/3/pset3.zip

Unzip that ZIP with this command: 

unzip pset3.zip

And then "cd into" the unzipped directory with this command: 

cd pset3/

Then proceed to follow the PDF's directions!

Caveats

  • For problem sets that involve phpMyAdmin, you should use your appliance's own installation.
  • For problem sets that involve web programming, your home will be http://192.168.56.50/~jharvard/, once you've created a ~/public_html/ directory.
  • Some commands mentioned in PDFs may not work inside of the appliance (e.g., challenge). We've made sure that the pedagogically important ones do, though.
  • Some source code might require tweaks to get it to compile inside of the appliance. If you run into a compilation error that's not discussed in the PDF, simply turn to the course's Google Group for assistance!

Implementation Details

Below are details on how we implemented the CS50 Appliance in case you're curious or would like to reproduce these steps yourself. You do NOT need to follow these directions to if you simply want to USE the CS50 Appliance: you only need to follow the instructions above.

We built the appliance with Ubuntu's vmbuilder, "a script that automates the process of creating a ready to use VM based on Ubuntu." Even though vmbuilder doesn't officially support creation of VirtualBox appliances, it does support creation of VMware appliances. But VirtualBox can read VMware virtual disks (*.vmdk files), so, by transitivity, you can use vmbuilder to create VirtualBox appliances!

It took us a while to figure everything out, but now that we (and you) know what we're doing, it only takes about 20 minutes to build the appliance (and most of that time is spent waiting for vmbuilder to run).

The directions below assume familiarity with Ubuntu and installation thereof as well as with VirtualBox. If you have questions, you may want to join CS50's Google Group at cs50.tv.

Install Ubuntu

First, you'll need a running instance of Ubuntu 10.04 with which to build the appliance. If you don't have such, download Ubuntu 10.04 from http://www.ubuntu.com/GetUbuntu/download (32-bit or 64-bit) and install it on a physical machine or in a virtual machine. Boot the OS, then make sure it's up-to-date: 

sudo aptitude update
sudo aptitude full-upgrade

Install vmbuilder

Installing vmbuilder is easy: 

sudo aptitude install python-vm-builder

Unfortunately, vmbuilder's --firstboot option is broken in Ubuntu 10.04 LTS, but a fix is available: 

sudo su -
wget http://launchpadlibrarian.net/47840185/vm-builder.bug536942.patch
cd /usr/share/pyshared/
patch -p1 < ~/vm-builder.bug536942.patch

Configure vmbuilder

If you're not (still) already, you might as well become root for simplicity: 

sudo su -

Provide your password if prompted.

Then, to speed things up (especially if you build the appliance multiple times) install APT's caching proxy: 

aptitude install apt-proxy

Then create a file called boot.sh in /root/ with these contents: 

############################################################################
# regenerate SSH keys (so that every user doesn't have same)
############################################################################

/bin/rm -f /etc/ssh/ssh_host*key*
/usr/sbin/dpkg-reconfigure -fnoninteractive -pcritical openssh-server


############################################################################
# remove MOTD
############################################################################

/bin/rm -f /etc/motd


############################################################################
# customize /etc/skel/
############################################################################

/bin/cat >> /etc/skel/.bashrc <<"EOF"

if [ -f /home/cs50/pub/etc/bashrc ]; then
  . /home/cs50/pub/etc/bashrc;
fi
EOF

/bin/cat >> /etc/skel/.profile <<"EOF"

if [ -f /home/cs50/pub/etc/profile ]; then
  . /home/cs50/pub/etc/profile;
fi
EOF
/bin/cp -f /etc/skel/.profile /home/jharvard/

/bin/cat >> /etc/skel/.bash_logout <<"EOF"

if [ -f /home/cs50/pub/etc/bash_logout ]; then
  . /home/cs50/pub/etc/bash_logout;
fi
EOF

/bin/chown -R jharvard:jharvard /home/jharvard


############################################################################
# configure cs50
############################################################################

/usr/sbin/adduser --disabled-login --system --uid 50 cs50
/bin/mkdir -p /home/cs50/pub/bin
/bin/mkdir -p /home/cs50/pub/etc

/bin/cat > /home/cs50/pub/bin/cs50ci <<"EOF"
#!/usr/bin/tcsh

onintr -

if ($#argv == 0) then
    /bin/echo "Usage: ci file"
    exit 1
else
    set files = "$argv[1*]"
endif

# ensure RCS directory exists
if ( ! -d RCS) then
    if ( -e RCS ) then
        mv -f RCS RCS.old
    endif
    /bin/mkdir RCS
endif

# check in file(s)
foreach file ( $files)
    if ( -f $file) then
        set type = `/usr/bin/file $file | grep text`
        if ( "$type" != "") then

            if ( ! -e RCS/$file,v ) then
                /usr/bin/rcs -i $file
                /usr/bin/rcs -U $file
            endif
            /usr/bin/ci -l $file
        endif
    endif
end

exit 0
EOF
/bin/chmod 0755 /home/cs50/pub/bin/cs50ci

/bin/cat > /home/cs50/pub/bin/cs50co <<"EOF"
#!/usr/bin/tcsh

onintr -

# ensure proper usage
if ($#argv == 0) then
    /bin/echo "Usage: co [-rversion] file"
    exit 1
else
    set files = "$argv[1*]"
endif

# handle versions
if ( "$argv[1]" == "-r" ) then
    if ( $#argv < 3 ) then
        echo "Usage: co [-rversion] file"
        exit 1
    endif

    set version = $argv[2]
    set files   = "$argv[3*]"

else if ( `/bin/echo $argv[1] | /bin/grep '^-r'` != "" ) then
    if ( $#argv < 2 ) then
        echo "Usage: co [-rversion] file"
        exit 1
    endif

    set version = `/bin/echo $argv[1] | /bin/sed -e 's/^-r//'`
    set files   = "$argv[2*]"
else
    set version = ""
    set files   = "$argv[1*]"
endif
endif

# ensure RCS directory exists
if ( ! -d RCS) then
    exit 1
endif

# check out file(s)
foreach file ( $files )
    if ( -e $file ) then
        /bin/rm -f .$file.bak
        /bin/cp $file .$file.bak
    endif
    /usr/bin/co -u$version $file
end

exit 0
EOF
/bin/chmod 0755 /home/cs50/pub/bin/cs50co

/bin/cat > /home/cs50/pub/etc/banner <<"EOF"

           ____   ___               _
   ___ ___| ___| / _ \   _ __   ___| |_
  / __/ __|___ \| | | | | '_ \ / _ \ __|
 | (__\__ \___) | |_| |_| | | |  __/ |_
  \___|___/____/ \___/(_)_| |_|\___|\__|

                 This is CS50. In a box.

                      CS50 Appliance 1.4


EOF

/bin/cat > /home/cs50/pub/etc/bashrc <<"EOF"
# set BASH_ENV
export BASH_ENV=~/.bashrc

# set umask
umask 0077

# configure prompt
export PS1="\u@\h (\w): "

# protect user
alias cp="cp -i"
alias mv="mv -i"
alias rm="rm -i"

# RCS
alias ci="/home/cs50/pub/bin/cs50ci"
alias co="/home/cs50/pub/bin/cs50co"

# allow core dumps
ulimit -c unlimited

# disable auto-logout
export TMOUT=0

# configure gcc
export CC=gcc
export CFLAGS="-ggdb -std=c99 -Wall -Werror -Wformat=0"
export LANG=C
export LDLIBS="-lcs50 -lm"
alias gcc="gcc $CFLAGS"

# if not running interactively, don't do anything else
[ -z "$PS1" ] && return

# show banner
if [ -f /home/cs50/pub/etc/banner ]; then
    /bin/cat /home/cs50/pub/etc/banner
fi
EOF

/bin/cat > /home/cs50/pub/etc/profile <<"EOF"
# prepend . to path
PATH=.:$PATH
export PATH
EOF

/bin/chown -R cs50:nogroup /home/cs50/
/bin/chmod 0711 /home/cs50
/bin/chmod -R a+rX /home/cs50/pub/


############################################################################
# configure jharvard
############################################################################

/bin/cp -f /etc/skel/.bashrc /home/jharvard/
/bin/cp -f /etc/skel/.profile /home/jharvard/
/bin/cp -f /etc/skel/.bash_logout /home/jharvard/


############################################################################
# configure rsnapshot (to automatically back up jharvard's C and PHP code
# every 10 minutes)
############################################################################

/bin/cat > /etc/rsnapshot.conf <<"EOF"
config_version	1.2
snapshot_root	/.snapshots/
cmd_rm		/bin/rm
cmd_rsync	/usr/bin/rsync
cmd_logger	/usr/bin/logger
interval	minutely	6
verbose		2
loglevel	3
lockfile	/var/run/rsnapshot.pid
include	*/
include	*.c
include	*.h
include	*.inc
include	*.php
exclude	*
include	Makefile
backup	/home		./
EOF
/bin/cat > /etc/cron.d/rsnapshot <<"EOF"
*/10 * * * * root /usr/bin/rsnapshot minutely
EOF


############################################################################
# configure Nano
############################################################################

/bin/cat > /etc/nanorc <<"EOF"
set autoindent
set const
set fill 80
set matchbrackets "(<[{)>]}"
set nowrap
set smooth
set suspend
set tabsize 4
include "/usr/share/nano/c.nanorc"
include "/usr/share/nano/html.nanorc"
include "/usr/share/nano/nanorc.nanorc"
EOF


############################################################################
# configure network
############################################################################

/bin/cat > /etc/network/interfaces <<"EOF"
auto lo
iface lo inet loopback

# NAT
auto eth0
iface eth0 inet dhcp

# Host-only Adapter
auto eth1
iface eth1 inet static
address 192.168.56.50
netmask 255.255.255.0
network 192.168.56.0
broadcast 192.168.56.255
EOF
/usr/bin/service networking restart


############################################################################
# configure suPHP
############################################################################

/bin/cat > /etc/apache2/mods-available/suphp.conf <<"EOF"
<IfModule mod_suphp.c>
	AddType application/x-httpd-suphp .php .php3 .php4 .php5 .phtml
	suPHP_AddHandler application/x-httpd-suphp

    <Directory />
        suPHP_Engine on
    </Directory>

    # By default, disable suPHP for debian packaged web applications as files
    # are owned by root and cannot be executed by suPHP because of min_uid.
    #<Directory /usr/share>
    #    suPHP_Engine off
    #</Directory>

# # Use a specific php config file (a dir which contains a php.ini file)
#	suPHP_ConfigPath /etc/php4/cgi/suphp/
# # Tells mod_suphp NOT to handle requests with the type <mime-type>.
#	suPHP_RemoveHandler <mime-type>
</IfModule>
EOF

/bin/sed -i -e 's/^docroot=.*/docroot=\//' /etc/suphp/suphp.conf
/bin/sed -i -e 's/^check_vhost_docroot=true/check_vhost_docroot=false/' /etc/suphp/suphp.conf
/bin/sed -i -e 's/^min_uid=.*/min_uid=1/' /etc/suphp/suphp.conf
/bin/sed -i -e 's/^min_gid=.*/min_gid=1/' /etc/suphp/suphp.conf
/bin/sed -i -e 's/^suPHP_Engine off/suPHP_Engine on/' /etc/apache2/mods-available/suphp.conf


############################################################################
# configure phpMyAdmin
############################################################################

/bin/chown -R www-data:www-data /usr/share/phpmyadmin
/bin/cat >> /etc/phpmyadmin/config.inc.php <<"EOF"

$cfg["Servers"][1]["AllowNoPassword"] = TRUE;
$cfg["Servers"][1]["auth_type"] = "http";
$cfg["Servers"][1]["hide_db"] = "information_schema";

EOF
/bin/ln -s /etc/phpmyadmin/apache.conf /etc/apache2/conf.d/phpmyadmin.conf


############################################################################
# configure Apache 
############################################################################

/bin/sed -i -e 's/^;session\.save_path = .*/session.save_path = "\/tmp"/' /etc/php5/cgi/php.ini
/usr/sbin/a2enmod userdir
/usr/bin/service apache2 restart


############################################################################
# configure MySQL (for pset7 and pset8)
############################################################################

/bin/cat | /usr/bin/mysql -u root <<"EOF"
CREATE USER 'jharvard'@'%' IDENTIFIED BY 'crimson';
GRANT USAGE ON *.* TO 'jharvard'@'%' IDENTIFIED BY 'crimson';
GRANT ALL PRIVILEGES ON `jharvard_%`.* TO 'jharvard'@'%';
CREATE DATABASE `jharvard_pset7`;
CREATE TABLE `jharvard_pset7`.`users` (
 `uid` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
 `username` VARCHAR(255) NOT NULL,
 `password` VARCHAR(255) NOT NULL,
 PRIMARY KEY (`uid`),
 UNIQUE KEY `username` (`username`)
) ENGINE = MYISAM;
INSERT INTO `jharvard_pset7`.`users` (`uid`, `username`, `password`) VALUES 
 (1, 'julius', '13'),
 (2, 'skroob', '12345'),
 (3, 'wbrandes', 'voice'),
 (4, 'baravelli', 'swordfish'),
 (5, 'blaise', 'FOOBAR'),
 (6, 'gcostanza', 'Bosco'),
 (7, 'malan', 'ftw!!!111');
CREATE DATABASE `jharvard_pset8`;
EOF
/usr/bin/mysqladmin -u root password "crimson"


############################################################################
# purge unused packages
############################################################################

/usr/bin/aptitude -q -y purge

This file, boot.sh, is a bash script that will be run the very first time the appliance boots up. You're welcome to alter the file as you see fit, especially if you don't need or like our customizations.

Create VMware Appliance

Now create the VMware (vmw6) appliance by executing the below in /root/: 

/usr/bin/vmbuilder vmw6 ubuntu --addpkg=acpid,apache2,build-essential,ethtool,firefox,ftp,gcc,gdb,gdm,gnome-app-install,gnome-core,gnome-system-tools,indicator-applet-session,language-selector,libapache2-mod-suphp,linux-headers-generic,lynx,make,manpages-dev,menu,mysql-client,mysql-server,nano,nautilus-open-terminal,ncftp,libapache2-mod-php5,libapache2-mod-suphp,libncurses5-dev,openssh-server,php5-cli,php5-mysql,phpmyadmin,rcs,rsnapshot,tcsh,unattended-upgrades,valgrind,vim,wamerican,wget,xorg,zip --arch=i386 --components=main,universe --copy=copy.txt --firstboot=boot.sh --flavour=generic --hostname=appliance --install-mirror=http://127.0.0.1:9999/ubuntu --lang=en_US.UTF-8 --name="John Harvard" --pass=crimson --removepkg=emacs,emacs22-gtk,emacs22-nox,gnome-media,gwibber,indicator-me,indicator-messages,libapache2-mod-php5,ubuntuone-client --rootsize=16384 --suite=lucid --swapsize=1024 --timezone=America/New_York --user=jharvard

20+ minutes later, you should have a directory called ubuntu-vmw6 in /root/, inside of which are two files: tmpm9biYE.vmdk (or something similarly pseudorandom) and appliance.vmx. Together, those files represent a VMware appliance: tmpm9biYE.vmdk is the appliance's virtual disk (hard drive), and appliance.vmx is the appliance's configuration. You're welcome to delete appliance.vmx; we're only going to use tmpm9biYE.vmdk to create our VirtualBox appliance.

Create VirtualBox Appliance

Rename tmpm9biYE.vmdk to disk0.vmdk and move it to a physical machine that has VirtualBox 3.2.6 or higher installed. (You may find it easiest to scp the file to that machine.) Launch VirtualBox and create a new VM as follows:

  1. Click New.
  2. Click Next.
  3. Input CS50 in a Box 1.4 for Name. Select Linux and Ubuntu for Operating System and Version respectively. (Do not select Ubuntu (64 bit).) Click Next.
  4. Input 512 MB for Base Memory Size.
  5. Leave Boot Hard Disk (Primary Master) checked. Select Use existing hard disk, then click the folder icon. Click Add, navigate your way to disk0.vmdk, click Open. (If you get an error message explaining that VirtualBox "Failed to open the hard disk," odds are you already have another VM using disk0.vmdk or you once had a VM that used disk0.vmdk. If the former, click Cancel and go delete that VM; if the latter, click Remove and remove disk0.vmdk from the Virtual Media Manager. Then resume or restart these steps.) It may take a few seconds for disk0.vmdk to appear in the list of Hard Disks. Once it does, make sure it's highlighted, then click Select. Then click Next.
  6. Click Finish if everything looks correct.
  7. Highlight CS50 in a Box 1.4 in VirtualBox's list of VMs, then click Settings.
  8. Click Network. On the Adapter 1 tab, make sure Enable Network Adapter is checked and that NAT is selected for Attached to. Click Adapter 2. Check Enable Network Adapter. Select Host-only Adapter for Attached to. Click OK.
  9. Select Export Appliance... from VirtualBox's File menu.
  10. Highlight CS50 in a Box 1.4 in the Appliance Export Wizard. Click Next.
  11. Click Next.
  12. Click Choose.... Create a new folder somewhere for the appliance. Input cs50-1.4.ovf for Save As. Click Save. Do not check Write legacy OVF 0.9.
  13. Click Export.
  14. An inaccurate number of seconds later, you should find three files in the folder you created: cs50-1.4.mf (which contains SHA1 hashes for cs50-1.4.ovf and cs50-1.4.vmdk), cs50-1.4.ovf (which contain's the VM's configuration), and cs50-1.4.vmdk (which is the VM's hard disk).
  15. Open cs50-1.4.ovf with a text editor and delete:
    1. the xmlns:vbox attribute in the Envelope element's start tag;
    2. the vbox:uuid attribute in the Disk element's tag;
    3. the entire Item element for ideController1 (i.e., everything between that IDE Controller's <Item> and </Item> tags);
    4. the entire vbox:Machine element (i.e., everything between <vbox:Machine ...> and </vbox:Machine>).
  16. Delete cs50-1.4.mf (or update the hash within for cs50-1.4.ovf).
  17. Create a ZIP file containing, at least, cs50-1.4.ovf and cs50-1.4.vmdk, and the appliance is ready for distribution!

Troubleshooting

If you are having problems that aren't addressed under Known Issues, turn to the course's Google Group for help.

Known Issues

  • 1.0.0
    • alias gcc gcc in /etc/csh.cshrc should be alias gcc gcc -ggdb -std=c99 -Wall -Werror -Wformat=0.
    • $PATH was incorrectly defined in /etc/csh.cshrc.
  • 1.0.1
    • /etc/csh.cshrc invokes `/bin/cat /etc/banner` for non-interactive shells, which breaks SFTP (which errs with, e.g., "Received message too long 169877536").
    • In /etc/network/interfaces, "broadcast" is misspelled.
    • On first boot, eth0 obtains DNS server(s) via DHCP, which then get saved permanently in /etc/resolv.conf, even if user moves to different network.
    • jharvard_pset7 database lacks users table.
  • 1.1
    • On (some) Windows hosts, when the appliance is first booted, VirtualBox displays a VERR_INTERNAL_ERROR, describing it as "Inexistent host networking interface, name 'vboxnet0'". This appears to be a bug in VirtualBox 3.2.x, but a workaround exists.
  • 1.2
    • Appliance continues not to import properly on (at least) Windows. Upon starting appliance (after import), VirtualBox reports "VERR_INTERNAL_ERROR: Inexistent host networking interface, named 'vboxnet0'" as well as, on occasion, errors pertaining to audio.
  • 1.3
    • PHPs do not work within John Harvard's account.
    • /usr/share/dict/words is missing.
  • 1.4
    • None at this time.

Changelog

  • 1.0.0
  • 1.01
    • Fixed bug in /etc/csh.cshrc whereby $variables in boot.sh were prematurely interpolated by changing EOT to "EOF" (because bash disables interpolation of $variables when heredocs' delimeters are quoted).
    • Changed all instances of EOT in boot.sh to "EOF" (for consistency's sake).
    • Upped appliance's video memory from 12MB to 17MB so that seamless mode would work.
  • 1.1
    • Upgraded OS from Ubuntu 9.04 (Karmic) to 10.04 LTS (Lucid).
    • Appliance no longer requires Internet access on first boot.
    • Changed eth0 to use DHCP (and thus obtain DNS server(s) dynamically).
    • Changed jharvard's shell from tcsh to bash.
    • phpMyAdmin is now pre-installed.
    • phpMyAdmin now requires authentication.
    • Changed hostname to "appliance".
    • Increased virtual disk size to 16 GB.
    • Appliance now includes jharvard_pset7.users table.
    • Appliance no longer requires PAE/NX support.
    • Fixed "Received message too long" SFTP problem.
    • Fixed misspelling of "broadcast" in /etc/network/interfaces.
  • 1.2
    • Added support for (CS50's version of) ci and co
    • Changed appliance to use PCnet FAST III virtual NICs instead of Intel PRO/1000 MT Desktop virtual NICs.
  • 1.3
    • Eliminated "VERR_INTERNAL_ERROR: Inexistent host networking interface, named 'vboxnet0'" problem, which appears to be a bug in VirtualBox 3.2.x.
  • 1.4
    • John Harvard's PHPs now work and execute as jharvard, while phpMyAdmin executes as www-data.
    • Appliance is now pre-configured with CS50 Library.
    • Installed /usr/share/dict/words.

Future Work

Future versions of the CS50 Appliance may include these features:

  • Ability to download source code from lectures and problem sets via apt-get, git, or svn.
  • Automatic updates to appliance via apt-get.

Resources

Acknowledgements

Many thanks to everyone who's helped us improve the CS50 Appliance, including, but not limited to:

  • Darrin Ragsdale
  • Dotty
  • Federico Lerner
  • Kartikeya Srivastava
  • Matthew Polega
  • Matthew Roknich
  • Rolando Cruz
  • Sergio Prado
Retrieved from "http://wiki.cs50.net/Appliance"
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