Installing LON-CAPA on a minimal Scientific Linux 6 System

This document guides you through the process of setting up a new LON-CAPA server running Scientific Linux 6 with a minimum of packages installed. The computer will be configured solely as a LON-CAPA server and will be expected to have no other services running. Your server 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 Unix 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:

Obtain Scientific Linux 6 installation CD
Determine Network Settings
Install Scientific Linux 5
Update your system
Install LON-CAPA
Create a Domain Coordinator
Start/Restart services
Log in to LON-CAPA

1. Obtain Scientific Linux 6 CDs

Scientific Linux isos can be obtained from links included on the Scientific Linux download page
For the minimal install on both 32-bit and 64 bit architecture you will need only the first CD.

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. Minimal Scientific Linux 6 Install

Installing Scientific Linux is quite easy, particularly if you've installed any of the Red Hat, Fedora or CentOS Linux distributions before. Documentation is available from http://www.scientificlinux.org/documentation/ Most of the installation screens are self explanatory. There are a few steps that require comment and are dealt with below.

Installation Language: Use English as your installation language.
Installation Type: If this is a fresh install choose "Install Scientific Linux Server". If updating from a previous LON-CAPA installation on an earlier Redhat or Fedora version you may prefer to choose the upgrade option, although if you established a separate partition for /home it will be faster to perform an install instead of an upgrade, and use "Create Custom Layout" to set up partitions - making sure to select the "unchanged data" option for the /home partition, in order to preserve your existing LON-CAPA data. A full back-up to tape or some external system is also strongly advised when updating the operating system in use on an existing LON-CAPA server.
Partitioning your Drive: For a fresh install may want to use the automatic partitioning feature of the installer, however you should review the results and be prepared to modify them. If you want to customize partitioning use "Create Custom Layout". 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 Scientific Linux, /home should receive at least 10 to 12 gigs. 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: Click the "Customize Now" radio button and for a minimal install uncheck all packages except "Base" in the Base System category. If you leave other packages checked in any of the other categories, you'll need additional ISO CDs.

Finish installing your server, reboot it, and log in as root. The first time you log-in, the Setup Agent will be displayed. (If you exit it early you can enter it again by running the command

setup

This tool should be used to configure the Firewall and SELinux.

Firewall Configuration

Select Security Level: Enabled, and Customize, to allow incoming: SSH (remote login), WWW (HTTP) and secure WWW (HTTPS).

Set SELinux to Disabled.

Select OK, and then Quit

4. Update your system

Update your system to the latest versions of the system software using yum.

yum update

Reboot your system before continuing with the installation.

Retrieve the scientific_loncapa_yum.conf file from the LON-CAPA install site:

wget http://install.loncapa.org/versions/scientific/6/scientific6_loncapa_yum.conf

Install the scientific_loncapa_yum.conf

mv /etc/yum.conf /etc/yum.conf.backup
cp scientific6_loncapa_yum.conf /etc/yum.conf
yum update

5. Installing LON-CAPA

Import the LON-CAPA encryption key

rpm --import http://install.loncapa.org/versions/scientific/RPM-GPG-KEY-loncapa

Install prerequisites

Execute:

yum install LONCAPA-prerequisites

This may take a moment due to LON-CAPA's large number of dependencies.

Retrieve and execute LON-CAPA setup program

Retrieve the LON-CAPA setup 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
./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 nine 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 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 /root/loncapa-N.N     (N.N should correspond to a version number like '1.3')
./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 users password. The password will show in plaintext as you type it. Feel free to use the "passwd username" command to change it later. Replace USERNAME and DOMAIN with an appropriate user name and your domain.

cd /root/loncapa-N.N/loncom/build
perl make_domain_coordinator.pl USERNAME DOMAIN
(WILL PROMPT FOR PASSWORD HERE)

7. Start/Restart Services

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

/etc/init.d/loncontrol start
/etc/init.d/httpd start

If you receive warnings when starting the httpd about missing perl modules, please make sure you followed the instructions in Installing LON-CAPA Dependencies. 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 send a help request to the MSU LON-CAPA group. If there were errors in installation of the dependency RPMs 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.