WeBWorK 2.17 Ubuntu Server 22.04 LTS Amazon Machine Image
These instructions cover setting up WeBWorK 2.17 using the WeBWorK 2.17 on Ubuntu Server 22.04 LTS AMI (Amazon Machine Image).
This version contains everything you need to run a WeBWorK server (e.g. WeBWorK, Ubuntu Server, Apache2, MariaDB, R server, log rotation, etc.) installed and configured.
Contents
- 1 Setting up the WeBWorK 2.17 Ubuntu Server 22.04 LTS Amazon Machine Image
- 2 Launch Your Server
- 3 Checking for and Installing Hotfixes
- 4 WeBWorK Configuration
- 5 Test that Things are Working Properly
- 6 Set up WeBWorK to use SSL
- 7 Finish up
- 8 Passwords
- 9 More House Keeping
- 10 File and Directory Locations and System Information
- 11 Known Issues
Setting up the WeBWorK 2.17 Ubuntu Server 22.04 LTS Amazon Machine Image
Overview
After using the WeBWorK 2.17 on Ubuntu Server 22.04 LTS Amazon Machine Image, you will have a full fledged Ubuntu Server 22.04 LTS system with WeBWorK 2.17, Apache2, MariaDB, R server, log rotation, etc. installed and configured.
It is imperative that you CHANGE THE PASSWORDS for the OS user wwadmin (who owns most WeBWorK files), for the MariaDB user webworkWrite who has access to MariaDB, for the WeBWorK user admin who has admin privileges and for the WeBWorK user profa who has professor privileges (see below). Finally you should set up SSL (https) access to WeBWorK if students will be using your server.
There are more detailed instructions for Ubuntu Server 22.04 and WeBWorK 2.17 at Installation Manual for 2.17 on Ubuntu. The AMI (Amazon Machine Image) was built following those instructions.
First you need an AWS account
First you need an Amazon AWS account. If you do not already have an account see https://aws.amazon.com/free/ and sign up for a free account. Or look at https://aws.amazon.com/premiumsupport/knowledge-center/create-and-activate-aws-account/.
Find the AMI image
Sign in to the AWS Management Console (https://signin.aws.amazon.com/) and search for "EC2 Dashboard". You will be taken to the Amazon EC2 console. From the navigation bar (at the top of the page), select the "US East (Ohio) us-east-2" region. You can select any Region that's available to you, regardless of your location but the AMI image is stored in the US East (Ohio) region so you have to use that one. In the navigation pane (to the left) under IMAGES, select AMIs. Then to the left of the search bar, select "Public images" (the choices are "Owned by me", "Public images", "Private images") and in the search bar enter "WeBWorK". You should see WeBWorK 2.17 on Ubuntu Server 22.04 LTS listed.
NOTE: If for whatever reason you can not or do not want to use the US East (Ohio) region, you can copy the AMI to another region. See https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/CopyingAMIs.html#ami-copy-steps or google "copy ami from one region to another".
Configure the WeBWorK AMI Image
Select the WeBWorK 2.17 on Ubuntu Server 22.04 LTS AMI and hit Launch instance from AMI
Name and tags
Name the instance and add additional tags if you want.
Choose an Instance Type
Information on ec2 instance types can be found at https://aws.amazon.com/ec2/instance-types/. I would suggest you look at t3a or maybe t2 and t3 Instances.
The WeBWorK AMI was built from a t3a.small ec2 instance having the following resources:
- 20 GB disk drive of which about 7 GB is used
- 2 GB memory
- 2 (virtual) cpu
The above resources are minimal. These resources are OK for testing but it is possible to overwhelm the machine. This may happen e.g. if you want to simultaneously display many problems in the Library Browser or if you have several simultaneous users. If this happens your options are to wait until the server recovers or reboot the server.
The Mathematical Association of America (MAA) courses1 server (which is no longer in use) was a t2.2xlarge ec2 instance having the following resources:
- 70 GB disk drive
- 32 GB memory
- 8 (virtual) cpu's
The MAA courses1 server was hosting over 600 courses of which around 150 were active in June, 2020.
Most likely the resources required for your server will fall within the range from small to 2xlarge. You can always change the resources available to an instance (see #Changing the instance type below) but for this you will have to stop the instance. After restarting, the instance will have a new IP address, which means you will have to change the network setup (see The WeBWorK URL below). For this reason it is best to start with reasonable resources. For a server that you will be using with students it might be reasonable to start with a small or medium instance. But of course this is highly dependent on the number of students who will be using the server simultaneously.
Select or Create a key pair
A key pair is used to securely log into your server. Create a new key pair or use an existing one. Download and save the pem file (e.g. WWsecretkey.pem).
Network Settings
You can use the default security group or create a new one.
You also should create inbound rules so that you and others can communicate with your server instance.
SSH (which you will use for direct terminal access to your server) is already set up but the source 0.0.0.0/0 means, as the warring states: "Rules with source of 0.0.0.0/0 allow all IP addresses to access your instance" but of course no one can login unless they have the appropriate credentials. You can restrict this to a specific workstation (e.g. 98.12.176.149/32) or a range (e.g.98.12.176.0/24) of ip addresses (e.g. workstations on your network). If you select "My IP", you will only be able to connect from your workstation which is good for security but maybe not convenience. You can always add other rules to SSH in from other workstations.
SSH TCP 22 98.12.176.149/32 SSH for admin
You should also allow HTTP (port 80). Initially for testing you may want to restrict these but for a production machine you would want to allow access from anywhere, i.e. 0.0.0.0/0. Note that except for guest users who have very limited access if you allow them at all, no one can log into WeBWorK on your server without a password. But see the section Passwords below for information on users who already have simple non secure passwords that must be changed.
Configure storage
You can change the amount of disk space. 20 GB is a reasonable amount to start with for a small server.
Also make sure that Delete on Termination is unchecked. Otherwise when you stop you instance, your root volume /dev/root (/dev/xvda1) will be deleted and this contains all changes you or your students may have made. Note that rebooting your server does not do this but stopping it (e.g. to increase memory or other resources) will.
Launch Your Server
Click "Launch instance" to launch your instance
Now Launch your server by clicking on "Launch instances". Clicking on the Instance ID is a fast way to get to your EC2 Dashboard. Or Click on "View all instances"
On your EC2 Dashboard (EC2 Management Console), find the Public IPv4 address, say 18.216.251.98. We will use this in our examples. Obviously you should substitute your own.
Accessing Your Server from a Terminal Emulator on your Host
You can login to your server using SSH (non secure telnet and FTP are not allowed but secure SSH and SFTP are) using your favorite terminal emulator. Note that I had to update my terminal emulator (MobaXterm) in order to connect. I recommend you use the latest version of your favorite terminal emulator.
If you use a terminal emulator like MobaXterm use the Advanced SSH Settings to use the WWsecretkey.pem file as your private key. Check the "private key" box, search for WWsecretkey.pem and then connect to 18.216.251.98 and login as ubuntu (no password required). Other terminal emulators (Putty, iTerm2, etc) will be similar.
If you are using ssh in a terminal window, use the command
ssh -i WWsecretkey.pem ubuntu@18.216.251.98
(you may have to provide the path to the WWsecretkey.pem file). Note that the permission on the WWsecretkey.pem file is required to be set so that the file is not readable by others. You need something like
chmod 600 WWsecretkey.pem
If you are using a bash shell running on Ubuntu under Windows 10, you may find it impossible to change the permission of WWsecretkey.pem. In that case copy WWsecretkey.pem to your home directory and change the permission there. From the directory containing WWsecretkey.pem
cp WWsecretkey.pem ~/ cd chmod 600 WWsecretkey.pem ssh -i WWsecretkey.pem ubuntu@18.216.251.98
Users on your system
There are two users who can login to the system: ubuntu and wwadmin
ubuntu
ubuntu is the "system" user who has sudo privileges. You probably always want to initially log in as ubuntu using the secret key file WWsecretkey.pem.
Running commands as root
By default your Ubuntu server has no password set for the root user. To gain root access you have to use the sudo command while logged in as ubuntu.
To run commands as root use
$ sudo <command>
A log of all sudo commands is kept in /var/log/auth.log .
You can also use sudo to become root and get the root prompt #. To do this run
$ sudo -s #
When you want to exit the root prompt and return to being the regular user ubuntu, do the following
# exit exit $
wwadmin
wwadmin is the "WeBWorK" administrator user who owns most of the WeBWorK system files. For example if you want to edit some WeBWorK file, you should use the su (switch user) command to become wwadmin. The password for wwadmin is "wwadmin" so the command is:
$ su wwadmin Password: wwadmin $
After you have finished whatever you have to do as wwadmin, you can return to being the ubuntu user by
$exit exit $
wwadmin is not in the sudo group so if you want to use sudo, you have to be ubuntu.
Also you should change the password for wwadmin to something much more secure than "wwadmin" (see Passwords).
Set the Timezone for your server
To find out what timezone your server is set to run the command
$ timedatectl
and you will see
... Time zone: Etc/UTC (UTC, +0000) ...
which is probably not where you live. The timezone naming convention uses a “Region/City” format and to find the correct one for your location run the command
$ timedatectl list-timezones
Look through the list and find your timezone, e.g. "America/Los_Angeles". Then set the timezone (you have to be root), e.g.
$ sudo timedatectl set-timezone America/Los_Angeles
and then
$ timedatectl
to check it was set correctly.
Checking for and Installing Hotfixes
Follow the instructions at Checking for and Installing Hotfixes in the Installation Manual for 2.17 on Ubuntu. NOTE that to check for and/or install updates you will have to become the wwadmin user:
$ su wwadmin Password: wwadmin $
Important: The are bug fixes for both the webwork2 code and the pg code that occurred after the AMI was built. You should definitely update both the webwork2 and pg code.
WeBWorK Configuration
The WeBWorK URL
We need a WeBWorK URL to give to students and professors so that they can access WeBWorK.
For this we can use your servers public ip address (e.g. 18.216.251.98) or public URL address (e.g. ec2-18.216.251.98.us-east-2.compute.amazonaws.com) but besides being hard to remember this is really not a good idea for the following reason. These public addresses are only "semi-permanent". As long as your server instance is running they will remain fixed and will also remain fixed if you reboot your instance. However, if you stop your instance for any reason (e.g. to increase the resources it has) the public addresses will disappear and when you restart your server, it will have new and different public addresses. Then you must tell all your users they need to use a new URL to access WeBWorK.
It is much better to use a permanent URL (something like webwork.yourschool.edu) and direct that to the public ip address of your instance (18.216.251.98 in our example). Then if your ever have to stop and restart your AWS instance, all you have to do is to redirect the webwork.yourschool.edu URL to the new public ip address and also change the ip address in one place (the $server_root_url) in site.conf. In my experience such changes propagate through the name servers quickly.
If for whatever reason you do not want to use a university URL, you can use Google Domains (https://domains.google/) or a similar provider to get and manage your own URL.
The WeBWorK .conf files
Most WeBWorK configuration is done in the files /opt/webwork/webwork2/conf/site.conf and /opt/webwork/webwork2/conf/localOverrides.conf. These files provide system-wide configuration settings, and defaults for course settings. Any setting in these files can be overridden in the course.conf file for a particular course. To override a setting for a course, just put the new setting (using the same syntax as is in localOverrides.conf) in the course.conf file. An instructor can only edit the course.conf file herself (for her own course) if she has "admin" privilege which by default professors do not have. But most things instructors may want to customize and many others (language, timezone, permissions, display modes, email, ...) can be set using the Course Configuration page from within the course and such setting override those in the configuration files.
Usually the "admin" user is added as an admin in all new courses and she can grant "admin" privileges to anyone (but she should be very careful in doing this).
Actually there are three main configuration files, site.conf, defaults.config and localOverrides.conf. The reason there are three configuration files is to make upgrading WeBWorK easier.
site.conf: This file contains global variables which are required for basic configuration. It will not be overridden when you update WeBWorK but its distribution version,site.conf.distwill be.defaults.config: This file contains initial settings for many customizable options in WeBWorK. Do not edit defaults.config. It will be overridden next time you upgrade.localOverrides.confThis is where you should add all local customizations. It will not be overridden when you update WeBWorK but its distribution version,localOverrides.conf.distwill be.
It is important to remember that any time you edit WeBWorK's configuration files, you have the restart Apache2 for the changes to take effect.
There are several options that must be set for WeBWorK to work with your system. The rest of the file consists of customization options.
Edit the site.conf file
Now backup and edit site.conf
$ su wwadmin Password: wwadmin $ cd /opt/webwork/webwork2/conf $ cp site.conf site.conf.bak1 $ nano site.conf
The $server_root_url is set as
$server_root_url = 'http://18.216.251.98/';
which you should replace with
$server_root_url = 'http://12.345.678.90/';
where of course replace 12.345.678.90 by your actual ip address.
WeBWorK uses the DateTime module. DateTime is supposed to be able to determine the local timezone itself without you having to enter it but this often fails so it is best to just set it here. For is a list of timezones recognized by DateTime run the command
timedatectl list-timezones
These timezones are more refined than standard time zone usage in that they include switches to daylight savings time (e.g. some parts of a time zone may make the switch and others may not). For example if your server is in the eastern US, on the list you will see America/New_York and you should enter $siteDefaults{timezone} = "America/New_York"; which is the default. Read the documentation in this section of the the site.conf file for more information on selecting time zones and formatting dates.
Search for $siteDefaults{timezone} and enter your local timezone if it is not correct.
Here is some information on email although you might want to hold off on this until you check that your server is functioning well.
WeBWorK sends mail in three instances. The PG system sends mail to report answers to questionnaires and free-response problems. The mail merge module is used to send mail to course participants, i.e. to report scores. The feedback module allows participants to send mail to course instructors.
To send mail, WeBWorK needs the address of an SMTP server. Normally you will use the address of your school's SMTP server. When connecting to the SMTP server, WeBWorK must also send an email address representing the sender of the email (this has nothing to do with the From address on the mail message). Edit the lines
$mail{smtpServer} = ; # e.g. 'mail.yourschool.edu' or 'localhost'
$mail{smtpSender} = ; # e.g. 'webwork@yourserver.yourschool.edu'
entering the appropriate information. Be sure to use single quotes and NOT double quotes around email addresses otherwise Perl will treat @ as an array variable.
If you do not use your school's SMTP server, the following documentation may be helpful:
https://docs.aws.amazon.com/ses/latest/DeveloperGuide/send-email-smtp.html
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-port-25-throttle/
https://docs.aws.amazon.com/ses/latest/DeveloperGuide/send-email-smtp-software-package.html
Or if you want to install your own SMTP server:
https://ubuntu.com/server/docs/mail-postfix
Then save the file and Quit.
Now restart apache so that our changes to the conf files takes effect. First we have to stop acting as wwadmin and return to the ubuntu user.
$ exit exit $ sudo apache2ctl restart
The defaults.config file
If you want WeBWorK questionnaires or similar things from different courses to be mailed to a central person or persons (e.g. the WeBWorK administrator), in defaults.config, you will see the lines
$mail{allowedRecipients} = [
#'prof1@yourserver.yourdomain.edu',
#'prof2@yourserver.yourdomain.edu',
];
But we are not supposed to edit the defaults.config file, so if we want to do this, we will copy this to localOverrides.conf and edit it appropriately. Note that we should move this setting to the site.conf file.
Edit the localOverrides.conf file
Now backup and edit localOverrides.conf
$ su wwadmin Password: wwadmin $ cd /opt/webwork/webwork2/conf $ cp localOverrides.conf localOverrides.conf.bak1 $ nano localOverrides.conf
As we said above,
if you want WeBWorK questionnaires or similar things from different courses to be mailed to a central person or persons (e.g. the WeBWorK administrator), in localoverrides.config, add and then edit the lines
$mail{allowedRecipients} = [
#'prof1@yourserver.yourdomain.edu',
#'prof2@yourserver.yourdomain.edu',
];
Of course you have to remove the comment character #.
Then save the file and Quit.
Now restart apache so that our changes to the conf files takes effect. First we have to stop acting as wwadmin and return to the ubuntu user.
$ exit exit $ sudo apache2ctl restart
Test that Things are Working Properly
Connect to http://webwork.yourschool.edu/webwork2 (or http://18.216.251.98/webwork2 if your haven't set up a URL yet) where of course you should use your actual URL or ip address.
We will test out a few important parts of WeBWorK. If you run into problems, you should look at the Apache error log which is located at /var/log/apache2/error.log. And you should look at Test that Things are Working Properly in the Installation_Manual_for_2.17_on_Ubuntu
for help.
You should see the WeBWorK Welcome page with "Course Administration" and "myTestCourse" listed. At some point you may want to "hide" them so that they are not listed on the Welcome page (more on this later).
Click on "myTestCourse" and login with login name "profa" and password "profa". At this point you are a regular professor. There is also an administrator "admin", a regular student "jsmith" and several guest or practice users (who don't require a password but can view problems and "check" answers without them being "submitted" for credit). More on these below.
Now click on Homework Sets on the Main Menu and click on Demo. Then look at the problems. Mathematical equations should be typeset. Continue looking at problems to see if everything is working properly. Look through the problems in the other sets.
Next click on Problem List to bring back the Problem List Page and click on Download PDF .... The page is a little complicated because you are a professor so you see the professor view (students see a very simple page) but you can just scroll to the bottom and click on Generate hardcopy for selected users and selected sets.
Look through the problems in the other sets.
Now test the Library Browser. Note when using the Library Browser the default is to view 20 problems at once. If you are using a micro ec2 instance level, this may overwhelm the server. A small or larger ec2 instance level should work fine. You can display fewer problems and e.g. use the "top" command to check the load on the server.
If "top" shows a high load average and/or shows the kswapd0 process taking a large percentage of cpu then your system is getting overwhelmed. In particular kswapd0 manages virtual memory and may be having issues due to moving processes to SWAP too frequently, causing cpu spikes and decreased system performance. The solution is to allocate more memory to your instance. If your server gets hopelessly bogged down, you can try to wait it out or just reboot.
Click on Library Browser on the Main Menu. Click Open Problem Library (actually it should already be selected so it will be greyed out)
and select a Subject, Chapter and Section and then hit View Problems. The first 20 of your selected problems will be displayed.
Next test that WeBWorK problems using R run properly. You are already in the Library Browser.
Select "Statistics" as Subject, "Bayesian inference" as Chapter and "Posterior distribution" as Section and then hit View Problems.
If the problems display with no error messages, all should be well. To be totally sure, click on the "eye" (Try it) in the upper right corner and test the problem. If there are no error messages, congratulate yourself. Everything works.
If you are new to WeBWorK or even if you are a pro, you should probably log in as a student to see what the student interface looks like. It's much simpler than the professor or admin interfaces. Login with login name "jsmith" and password "jsmith". The "admin" view is very similar to the "prof" view but you have the ability to change things about the course that mere professors do not have. Finally you can click on "Guest Login" and see what that looks like.
Set up WeBWorK to use SSL
This step configures apache so that access to WeBWorK will be through an encrypted connection (SSL) with an https: URL. It is optional but you should certainly do this if students will be using your server. Note that TLS is the successor protocol to SSL and is used everywhere. So that when we and others use the more common acronym SSL, we really are talking about TLS. The non encrypted lighttpd server is being used for images, MathJax, etc. so we should also set up the lighttpd server to run under SSL (see below).
First we have to obtain an official SSL certificate or generate a self-signed one which can be used for testing purposes. If students will be using your server, it is much better to obtain an official SSL certificate since using a self-signed certificate with cause warning messages to be displayed when students connect to the server.
Obtain an Official SSL Certificate
Talk to the networking group on your campus about obtaining an official certificate. You can find information on the net about certificate providers, e.g. http://www.sslshopper.com/certificate-authority-reviews.html . Certbot (https://certbot.eff.org/) which uses Let's Encrypt certificates (https://letsencrypt.org/) is a good option if you are not using your organization's official certificates.
The certificate goes in /etc/ssl/certs/ and the key file goes in /etc/ssl/private/.
Use a self-signed Certificate
When we installed the package openssh-server a self-signed certificate was automatically created. The certificate is stored at
/etc/ssl/certs/ssl-cert-snakeoil.pem
and the private key at
/etc/ssl/private/ssl-cert-snakeoil.key
This certificate and key may be regenerated manually with the following command (needs root privileges i.e. sudo):
$ sudo make-ssl-cert generate-default-snakeoil --force-overwrite
which you might want to do since I believe the original certificate is only valid for 365 days.
In the instructions below we will use the provided self-signed certificate (ssl-cert-snakeoil.pem and ssl-cert-snakeoil.key) but you can also generate your own using openssh following instructions on the web. As we said above, for a production server, you should really use an official certificate.
Add inbound rules for Apache
Create inbound rules for Apache on port 443. On your EC2 Management console, select the "Security Group" for your instance, "Inbound Rules", "Edit inbound rules" and then "Add rule" finally add the rule
HTTPS TCP 443 0.0.0.0/0 HTTPS
Initially for testing you may want to restrict these but for a production machine you would want to allow from anywhere, i.e. 0.0.0.0/0
Set up Apache to use SSL
First we enable the mod_ssl module
$ sudo a2enmod ssl
Now we have to configure Apache to use SSL.
$ cd /etc/apache2/sites-available/ $ sudo cp default-ssl.conf default-ssl.conf.bak1 $ sudo nano default-ssl.conf
Our self-signed certificate and key files are named
ssl-cert-snakeoil.pem and ssl-cert-snakeoil.key. If you
are using official files, put their names in the lines below. You will also have to edit the Certificate Chain, Certificate Authority and possibly other items. Instructions for doing so are beyond the scope of this document. You might look at https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-ubuntu-20-04
Search for the lines
SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key
and replace ssl-cert-snakeoil.pem and ssl-cert-snakeoil.key by the names of your certificate. Since in these instructions we are using
ssl-cert-snakeoil.pem and ssl-cert-snakeoil.key, we can just leave the lines as is.
Then save the file and quit. And enable default-ssl.conf
$ sudo a2ensite default-ssl.conf
Finally we restart Apache
$ sudo systemctl restart apache2
Edit site.conf
This is important. We have to edit the value of $server_root_url in webwork2/conf/site.conf so that it uses https (so it should read e.g. 'https://12.345.678.90') where of course replace 12.345.678.90 by your actual ip address. If you don't do this, your may run into strange problems in the Library Browser. To check, open the Library Browser, select a subject and then click on the chapter area. If you see a drop down list of chapters, things are working properly.
Now we edit site.conf
$ su wwadmin Password: wwadmin $ cd /opt/webwork/webwork2/conf $ cp site.conf site.conf.bak1 $ nano site.conf
In the line
$server_root_url = 'http://12.345.678.90';
replace http by https where of course your file has your real ip address. Then save the file, quit, return to being the ubuntu user and restart apache
$ exit exit $ sudo service apache2 restart
Test that things are still working properly
Connect to https://yourserver.yourschool.edu/webwork2/myTestCourse You will be asked to accept the certificate. After you do so things should work just as before except that the connection will be via https.
Redirect http requests to https
Assuming that everything is working, the last thing we do is set things up so that requests to http://yourserver.yourschool.edu/webwork2/ are automatically redirected to https://yourserver.yourschool.edu/webwork2/.
$ cd /etc/apache2/sites-available $ sudo cp 000-default.conf 000-default.conf.bak1 $ sudo nano 000-default.conf
In the
<VirtualHost *:80>
section just under the line
DocumentRoot /var/www/html
add the line
Redirect permanent /webwork2 https://yourserver.yourschool.edu/webwork2
where of course you should edit yourserver.yourschool.edu appropriately.
Then save the file and quit.
Restart Apache
$ sudo service apache2 restart
and try connecting to http://yourserver.yourschool.edu/webwork2/. The real connection should be through https://yourserver.yourschool.edu/webwork2/.
Finish up
Once access to your WeBWorK server is set up (as it should be now), if all you want to do is test out WeBWorK yourself without any other users, you are all set at this point but please read the rest of these instructions so that you understand how insecure your WeBWorK server is right now.
Passwords
It is IMPERATIVE that you CHANGE THE PASSWORD for the OS user wwadmin (who has ownership of the WeBWorK files). Otherwise anyone can connect to your server and pretty easily gain access to the WeBWorK files. Also it is IMPERATIVE that you CHANGE THE PASSWORD for the MariaDB user webworkWrite who has login privileges to MariaDB. Otherwise anyone can connect to MariaDB server and pretty easily gain access to the WeBWorK database. Finally it is IMPERATIVE that you CHANGE THE PASSWORD for the WeBWorK user admin who has admin privileges both in the admin course and in the myTestCourse and for the WeBWorK user profa who has professor privileges in the myTestCourse. Otherwise anyone can connect to WeBWorK server and pretty easily gain access and do anything they want.
Change the password for wwadmin
$su wwadmin Password: wwadmin $ passwd Changing passwd for wwadmin: (current) UNIX password: wwadmin Enter new UNIX password:<new wwadmin password>Retype new UNIX password:<new wwadmin password>passwd: password update successfully $exit exit $
Do not forget the <new wwadmin password> that you just entered. Below when we refer to <wwadmin password>, we mean the new <wwadmin password> (<new wwadmin password>).
Change the password for webworkWrite
Now we change the passwords for the MariaDB user webworkWrite. First we edit site.conf.
$su wwadmin Password: <wwadmin password> $ cd /opt/webwork/webwork2/conf $ nano site.conf
Search for $database_password = "wwadmin"; and replace this by
$database_password = "database_password";
where of course you should replace 'database_password' with your own password. We refer to this password as <database_password>. Remember it as we will need it shortly. Then save the file and Quit.
Then restart Apache so the changes take effect.
$ exit exit $ sudo apache2ctl graceful
and start MariaDB
$ sudo mysql
You should see
Welcome to the MariaDB monitor ... MariaDBl>
Now lets check the MariaDB users.
MariaDB> SELECT user,password,authentication_string,plugin,host FROM mysql.user;
You will see a table with two users (root and webworkWrite).
You should see that both users have a valid password (which will be displayed in encrypted form) and root is authenticated by a socket.
Now we will change the password for the webworkWrite User
MariaDB> ALTER USER 'webworkWrite'@'localhost' IDENTIFIED BY '<database_password>';
where of course you should replace <database_password> by whatever you used above (use the single quotes but no angle braces). Then
MariaDB> FLUSH PRIVILEGES; use your up arrow key to run the command MariaDB> SELECT user,password,authentication_string,plugin,host FROM mysql.user;
and you should see that webworkWrite has a new passwords (which will be displayed in encrypted form).
Then exit MariaDB
MariaDB> exit Bye $
If you want to check that you set the password correctly, do the following:
mysql -u webworkWrite -p -h127.0.0.1 --protocol=tcp Enter password: <database_password>
and you should see
Welcome to the MariaDB monitor ... MariaDBl>
Now exit
MariaDB> exit Bye $
Finally a note on the MariaDB root password. In Ubuntu systems running MariaDB, the MariaDB root user is set to authenticate using the auth_socket plugin by default rather than with a password. However in securing MariaDB (see Installation_Manual_for_2.16_on_Ubuntu#Securing_the_Database) we had to set a password for the MariaDB root user and that password was set to "wwadmin" even though it is not used. If you ever change how the MariaDB root user is authenticated (you shouldn't!!), remember this.
Change the password for admin
Change the passwords for the WeBWorK user admin in two courses. Login to both the WeBWorK admin course (http://.../webwork2/admin) and myTestCourse (http://.../webwork2/myTestCourse) with Username "admin" and Password "admin". Then change the passwords from "admin" to something more secure. Note that in WeBWorK to change the password of the user you are logged in as, select "User Settings" in the "MAIN MENU". Or you can login as "profa" and use the "Classlist Editor" to change the password.
Change the password for profa
Change the passwords for the WeBWorK user profa. Login to myTestCourse (http://.../webwork2/myTestCourse) with Username "profa" and Password "profa". Then change the passwords from "profa" to something more secure. Or you can login as "admin" and use the "Classlist Editor" to change the password.
Change the password for jsmith
Change the passwords for the WeBWorK user jsmith if you want. jsmith is just a regular student so she can't do any real damage but you may still want to change the password. Login to myTestCourse (http://.../webwork2/myTestCourse) with Username "jsmith" and Password "jsmith". Then change the passwords from "jsmith" to something more secure. Or you can login as "admin" or "profa" and use the "Classlist Editor" to change the password.
More House Keeping
Hide the admin and myTestCourse courses
Log out of myTestCourse if you are logged in and go to the WeBWorK Welcome page. Click on Course Administration and login as admin with the new admin password you set for the admin course. Select "Hide Inactive Courses" and select the courses you want to hide and hit "Hide Courses". If you go back to the WeBWorK Welcome page, you will see no courses listed. You can still access these courses directly by
http://webwork.yourschool.edu/webwork2/admin http://webwork.yourschool.edu/webwork2/mytestcourse
where of course you should use your actual URL.
Institution Logo
The institution logo (which is the MAA logo by default) appears on every WeBWorK page. You can replace with you own logo by doing the following. We took these directions verbatim from Alex Jordan's Forum post https://webwork.maa.org/moodle/mod/forum/discuss.php?d=5642.
All you need to do is add lines like these to a config file like localOverrides.conf:
$institutionLogo = 'myimage'; $institutionURL = 'URL for target if a user clicks on the image'; $institutionName = 'Name of the target, to be used in alt text';
myimage is an image file that you place in webwork2/htdocs/themes/math4/images/. It could be for example 'myimage.svg' containing some text.
The easiest way to do this is to search for the lines
# The institution logo should be an image file in the theme's images folder #$institutionLogo = 'my_school_logo.png'; #$institutionURL = 'http://www.myschool.edu'; #$institutionName = 'My University';
in /opt/webwork/webwork2/conf/localOverrides.conf, remove the #'s from the last three lines and enter your information.
If you want to just make the change for an individual course, copy the code and put it in
/opt/webwork/courses/Course_Name/course.conf.
Adjust Apache's configuration according to your server's memory
Look at Edit mpm_prefork.conf in the Installation Manual for 2.15 on Ubuntu 20.04 Server and adjust "MaxRequestWorkers" according to the rule of thumb given there.
Set up access to Apache's server-info and servo-status
This isn't really necessary but you should look at the info.conf and status.conf section in Installation Manual for 2.16 on Ubuntu.
Changing the instance type
For general information look at the following reference and also google "change the instance type of ec2"
Important: When you stop you instance (as you have to do to change the instance type), your root volume /dev/root (/dev/xvda1) will be saved and this contains all changes you or your students may have made. This is because when your instance was created "Delete on Termination" was unchecked (unless you explicitly changed that). Otherwise when you stop you instance, your root volume /dev/sda1 will be deleted. If necessary you can change this setting for a running instance.
First you should review information on ec2 instance types can be found at https://aws.amazon.com/ec2/instance-types/. I would suggest you look at t2 Instances.
Sign in to the AWS Management Console (https://signin.aws.amazon.com/) and search for the "EC2" service. You will be taken to the Amazon EC2 console.
- In the navigation pane, choose Instances.
- Select the instance and choose Actions, Instance State, Stop.
- In the confirmation dialog box, choose Yes, Stop. It can take a few minutes for the instance to stop.
- With the instance still selected, choose Actions, Instance Settings, Change Instance Type. This action is disabled if the instance state is not stopped.
- In the Change Instance Type dialog box, do the following:
- From Instance Type, select the instance type that you want.
- (Optional) If the instance type that you selected supports EBS–optimization, select EBS-optimized to enable EBS–optimization or deselect EBS-optimized to disable EBS–optimization. If the instance type that you selected is EBS–optimized by default, EBS-optimized is selected and you can't deselect it.
- Choose Apply to accept the new settings.
- To restart the stopped instance, select the instance and choose Actions, Instance State, Start.
After your instance starts, find its new public ip address and redirect your fixed URL (webwork.yourschool.edu in our example above) to the new ip address.
Also you have to Edit the site.conf file setting ehe $server_root_url to the new public ip address.
Look at The WeBWorK URL for an explanation. Also remember to #Adjust Apache's configuration according to your server's memory.
Increase disk space
This is a two part process. The first step is
Expand the EBS root volume
For general information look at the following reference and also google "expand disk of ec2"
Sign in to the AWS Management Console (https://signin.aws.amazon.com/) and search for the "EC2" service. You will be taken to the Amazon EC2 console. In the navigation pane (to the left), choose "Volumes", right click on the volume you what to expand and select "Modify Volume". In the pop up window select the new size, say 25, and click "Modify" and then confirm by clicking "Yes". You will see
Modify Volume Request Succeeded Your volume is now being modified.
The second step is to
Repartition the disk and expand the file system
Let us assume you have completed the first step and expanded the disk capacity from it's initial 20 GB to 25GB although in practice you will probably want to make it larger. First enter
$ df -h Filesystem Size Used Avail Use% Mounted on /dev/root 20G 5.3G 15G 28% / ...
to see how much disk space we have initially. Now run parted as root:
$ sudo parted
and you will see something like
GNU Parted 3.3 Using /dev/xvda Welcome to GNU Parted! Type 'help' to view a list of commands. (parted)
Now enter the "print" command
(parted) print Model: Xen Virtual Block Device (xvd) Disk /dev/xvda: 26.8GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 1049kB 21.5GB 21.5GB primary ext4 boot (parted)
We need to know the number of the partition we want to resize. We can see it is 1 from the above. Now enter the "resizepart" command
(parted) resizepart Partition number? 1 Warning: Partition /dev/xvda1 is being used. Are you sure you want to continue? Yes/No? Yes End? [21.5GB]? 26.5GB (parted)
Now enter the "print" command again
(parted) print Model: Xen Virtual Block Device (xvd) Disk /dev/xvda: 26.8GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 1049kB 26.5GB 26.5GB primary ext4 boot (parted)
Notice we now have a 26.5 GB disk. Now quit parted.
(parted) quit Information: You may need to update /etc/fstab.
Now we resize the file system. The above information tells us that we are working on partition 1 on /dev/xvda, so we use /dev/xvda1 in the command below
$ sudo resize2fs /dev/xvda1 resize2fs 1.45.5 (07-Jan-2020) Filesystem at /dev/xvda1 is mounted on /; on-line resizing required old_desc_blocks = 3, new_desc_blocks = 4 The filesystem on /dev/xvda1 is now 6469470 (4k) blocks long.
and run df -h and we should see something like
$ df -h Filesystem Size Used Avail Use% Mounted on /dev/root 24G 5.3G 19G 23% / ...
indicating that we now a lot more space on our disk. Yea!
File and Directory Locations and System Information
This installation of WeBWorK and Ubuntu follows the instructions given in Installation_Manual_for_2.17_on_Ubuntu. You can look there to find the locations of the WeBWorK files. MathJax is installed locally and optional configurations B and C are implemented.
- Optional A is not implemented. Option A configures Apache so that access to WeBWorK will be through an encrypted connection (TLS/SSL) with an https: URL. This has to be done locally and you may have already implemented this.
Consult Category:Administrators for other WeBWorK documentation for system administrators.
Known Issues
Here are the known issues with this release.
PGbasicmacros.pl
Displaying certain symbols (e.g. {, },<,>,≤, ≥) in the text (not in Math Mode) of a WeBWorK problem fails. An example is Problem 1 in Set 0 in "myTestCourse" (see Test that Things are Working Properly below). For information on this see https://github.com/openwebwork/pg/issues/473. This can be fixed. However the fix causes trouble with WeBWorK problems that use the associated macros incorrectly in Math Mode (see https://webwork.maa.org/moodle/mod/forum/discuss.php?d=5727) and there are quite a few more problems that use them incorrectly than correctly. If you use any of these problems, the easiest solution would be to not perform the fix.
If you do what to proceed with the fix we need to edit the PGbasicmacros.pl file.
$ cd /opt/webwork/pg/macros $ cp PGbasicmacros.pl PGbasicmacros.pl.bak1
$ nano PGbasicmacros.pl
Look for the line
HTML_MathJax => [ "HTML_dpng", "HTML_tth", "HTML", ],
and replace it by
#HTML_MathJax => [ "HTML_dpng", "HTML_tth", "HTML", ], HTML_MathJax => [ "HTML_dpng", "HTML", "HTML_tth", ],
Then save the file and Quit.
-- Main.ArnoldPizer - August 2022
