Debian 11 Install

Installing LON-CAPA on a basic Debian 11 Server

This document guides you through the process of setting up a new LON-CAPA server/VM running Debian 11 with only the base set of packages installed. The machine (virtual or real) will be configured solely as a LON-CAPA server and will be expected to have no other services running. Your server/VM is expected to have a reasonably fast connection to the internet.

More information is available at http://install.lon-capa.org/.

Before you begin

Installing Linux is getting easier and easier. You will be required to log in to the machine and execute some routine Linux commands. Familiarity with the Apache web server, mod_perl, perl, and MySQL are not required to install and run LON-CAPA.

Installation Overview

The installation process takes the following steps:

1. Obtain Debian 11 .iso
2. Determine Network Settings
3. Install Debian 11
4. Update your system
5. Install LON-CAPA
6. Create a Domain Coordinator
7. Start/Restart services
8. Log in to LON-CAPA

1. Obtain Debian 11 .iso file

Debian 11 .iso files can be obtained from the Getting Debian page. Either a small installation image .iso for installation over the network or a larger complete installation image .iso can be downloaded.

2. Determine Network Settings

You will need to know the following network settings for your installation. Note:You must have a static IP address to use LON-CAPA. DHCP is not supported.

• ip address
• netmask
• hostname
• gateway
• domain name server(s)

3. Debian 11 installation

Installing Debian Linux is straightforward. Documentation is available from https://www.debian.org/releases/stable/installmanual/ Most of the installation screens are self explanatory. (Choose "Graphical Install"). There are a few steps that require comment and are dealt with below.

Installation Language

Use English as your installation language.

Partitioning your Drive

For a fresh install you may want to use the automatic partitioning feature of the installer. If you decide to customize partitioning, the following may be useful to know. LON-CAPA resource files are stored in the /home directory, so the majority of the disk space should be allocated here. If you have 20 GB of space for Debian, /home should receive at least 10 to 12 GB. Since MySQL uses the /var filesystem to store its databases you should have at least 4 gigs of space available on /var. Be sure to include adequate swap space. A minimum is 512 Megs, but you should typically have 1 or 2x as much swap space as you do physical RAM.

Network Configuration

LON-CAPA will not work with a machine set up to use a dynamic IP address. When configuring your network card, be sure to unselect the DHCP option and enter in your network information.

Software Selection

The base system will be installed. Once that is complete you will have the option to select additional software collections. By default, "standard system utilities" will be checked -- leave that checked, and (optionally) also check SSH Server, if you plan to ssh into your Debian 11 Server/VM from another machine.

Finish installing your server, reboot it, and log in with the username you created during installation.

Enabling sudo

If you wish to allow the username created during installation to have administration privileges using sudo, use su to become root and execute the following, replacing <username> with that specific username:

apt-get install sudo
/sbin/adduser <username> sudo
exit

Now logout and log in again with that username. If you prefer not to use sudo, then you should omit all instances of sudo when executing all commands listed on the remainder of this page, after using su to become root.

Firewall Configuration

Use ufw to allow incoming traffic for the following services: ssh, www, https

Check if ufw is installed

sudo dpkg-query -s ufw |grep Status

If the result is not: Status: install ok installed, then install it:

sudo apt-get install ufw

Configure ufw by executing the following:

sudo ufw default deny
sudo ufw enable
sudo ufw allow ssh
sudo ufw allow www
sudo ufw allow https
sudo ufw reload

E-mail: Postfix Installation

Configure to "Internet Site" to allow LON-CAPA to send e-mail to users.

sudo apt-get install postfix

E-mail: Postfix Configuration

If you need to change the postfix configuration in the future use:

sudo dpkg-reconfigure postfix

Time synchronization service

You will use chrony for time synchronization, so if timesyncd is installed you should remove it.

sudo systemctl stop systemd-timesyncd
sudo systemctl disable systemd-timesyncd
sudo apt-get remove systemd-timesyncd
sudo apt-get install chrony
sudo systemctl start chrony
sudo systemctl enable chrony

4. Update your system

Update your system to the latest versions of the system software using apt-get

sudo apt-get update
sudo apt-get upgrade

If kernel packages were updated, reboot your system before continuing with the installation.

5. Installing LON-CAPA

Import the LON-CAPA encryption key

Check if gpg is installed

sudo dpkg-query -s gpg |grep Status

If the result is not: Status: install ok installed, then install it:

sudo apt-get install gpg

Check if wget is installed

sudo dpkg-query -s wget |grep Status

If the result is not: Status: install ok installed, then install it:

sudo apt-get install wget

Check if /etc/apt/keyrings directory exists by executing:

ls -al /etc/apt/keyrings

If it is missing, create it by executing:

sudo mkdir /etc/apt/keyrings

Execute:

wget -q -O - https://install.loncapa.org/versions/debian/APT-GPG-KEY-loncapa.asc | gpg --dearmor | sudo tee /etc/apt/keyrings/loncapa.gpg > /dev/null

Add LON-CAPA debian repository to /etc/apt/sources.list.d

Execute:

echo "deb [signed-by=/etc/apt/keyrings/loncapa.gpg] https://install.loncapa.org/debian bullseye main" | sudo tee /etc/apt/sources.list.d/loncapa.list

You can display which standard Debian repositories are currently enabled by executing:

grep '^deb ' /etc/apt/sources.list |grep ' bullseye'

The output should be similar to the following (with deb.debian.org replaced with your preferred mirror site):

deb http://deb.debian.org bullseye main
deb http://security.debian.org/debian-security bullseye-security main
deb http://deb.debian.org bullseye-updates main

Install prerequisites

Execute:

sudo apt-get update
sudo apt-get install loncapa-prerequisites

This may take some minutes due to LON-CAPA's large number of dependencies.

Set MPM mode for Apache web server and enable use of cgi scripts and webDAV

Execute:

sudo a2dismod mpm_event
sudo a2enmod mpm_prefork
sudo a2enmod cgi
sudo a2enmod dav
sudo a2enmod dav_fs

Retrieve and execute LON-CAPA setup program

Retrieve the LON-CAPA setup script and dependencies with the following command:

wget http://install.loncapa.org/linux/install.tar

Extract the archive with the following command:

tar xf install.tar

This creates a directory named installation. Change to it and execute the setup script with the following commands:

cd installation
sudo ./install.pl

The script is used to prepare a Linux system to run LON-CAPA, and can also be used to check the configuration of a system on which LON-CAPA has already been installed. Typically, though, you will run this script only once, when you first install LON-CAPA.

The script will analyze your system to determine which actions are recommended. The script will then prompt you to choose the actions you would like taken. Once a choice has been entered for all ten possible actions, required changes will be made.

The possible actions are:

• Create the www user/group
• Install the package LON-CAPA uses to authenticate users.
• Set-up the MySQL database
• Set-up MySQL permissions
• Configure Apache web server
• Configure systemd security settings for Apache web server
• Configure start-up of services
• Check firewall settings
• Stop services not used by LON-CAPA,
  e.g., services for a print server: cups daemon
• Download LON-CAPA source code in readiness for installation

Determine LON-CAPA Settings

LON-CAPA requires a number of identifying parameters to be set in order for it to function at all. Below is a list with descriptions.

Host Type (library or access)

The server must be designated a 'library' or an 'access' server. In general you should have a library server for your instructors to create their course content on and run their courses. Students should connect to access servers. If you are doing the first install of LON-CAPA at your site, or if you are playing with it for your own edification you should make your machine a 'library' server.

LON-CAPA domain

Each site or school which installs LON-CAPA needs its own domain. Here at MSU we use 'msu'. You should choose something short but meaningful. Restriction: One word, no hyphens, underscores, or special characters.
Domain names which include a departmental abbreviation are not recommended as although LON-CAPA may start in a single department, other departments frequently join subsequently. For a domain name: 'msu' is a superior choice to 'msuphys' for example.

LON-CAPA host id

Each LON-CAPA server requires a unique internal name. We use names such as "msul1" for the first library server. Restriction: One word, no hyphens, underscores, or special characters.

Domain's Primary Library Server ID

If you are setting up a domain with a single library server, then the domain's primary library server ID will be the LON-CAPA host id of that server (e.g., msul1). Once your domain grows and you need to add more servers, one of the library servers in the domain should be assigned as the domain's primary library server. This will be where domain-wide settings will be stored.

Host administrator email

The amount of email sent to this address is relatively minimal. Messages are sent every time the system starts up, or if the system is in serious trouble. On a laptop, make this root@localhost.

Support email address

If you enter an e-mail address here, then users of the system will be able to click an "Ask Helpdesk" link in the system to display a web form which they will complete to request support from your institution's helpdesk. On form submission the contents will be sent to the e-mail address you specify.

Configuring LON-CAPA

To configure and install LON-CAPA, execute the following commands:

cd ../loncapa-X.Y.Z  (X.Y.Z should correspond to a version number like '2.11.5')
sudo ./UPDATE

You will need to enter the LON-CAPA configuration information you determined in the previous section.

6. Creating a Domain Coordinator

You will need at least one user at your site who has the role of 'domain coordinator'. This user creates accounts for other users and grants them additional privileges. The make_domain_coordinator.pl script invoked below requires that you enter the user's password. Replace USERNAME and DOMAIN with an appropriate username and your domain.

cd loncom/build
sudo perl make_domain_coordinator.pl USERNAME DOMAIN
cd

7. Start/Restart Services

The LON-CAPA network services take a moment to start. Most misconfigurations will be apparent at this step.

sudo /home/httpd/perl/loncontrol start
sudo systemctl restart apache2
exit

If you receive warnings about missing perl modules when starting Apache, please make sure you followed the instructions in Installing prerequisites. If you still have errors, please contact the MSU LON-CAPA group.

8. Log in to your LON-CAPA Machine

Point a web browser at your new machine and log in as the domain coordinator. Congratulations!

If things aren't working right

If you've followed the steps above and the server doesn't start or you think there's something wrong, please contact the LON-CAPA helpdesk. Installation/update support is available from: helpdesk at loncapa.org (replace " at " with @). If there were errors in installation of the dependency .deb packages or errors during the automatic setup, please send us as much information as possible. If some part of this document is unclear please let us know.

Contact Us: lon-capa@lon-capa.org

Supported by the National Science Foundation under NSF-ITR 0085921, NSF-CCLI-ASA 0243126, and NSF-CCLI 0717790. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Initial funding for CAPA has been provided by the Alfred. P. Sloan Foundation and the Andrew W. Mellon Foundation.