User:Holt/XS Community Edition/0.2/Project Specifications
School Server - Community Edition 0.2 Project Specifications
Executive summary
The school server is very similar in concept to a standard home wireless router. In everyday usage it provides various services which extend capabilities of the connected laptops while being totally transparent to the user. These services can include:
- Network connection – various services similar to what you would find in a home router.
- Presence server – Augments sugar's native collaboration functionality.
- Web filtering – Enables schools to comply with local legal restrictions on internet access for children.
- FUTURE - Security – XO related security services.
- FUTURE - Content management
Reference User
The XS-CE has two different types of reference user:
- Skilled sysadmins running micro-deployments
- OLPC-AU schools.
As a result this design might not apply in all situations in all deployments. These limitations ease design and development while creating a functional reference implementation.
Hardware
School servers can be either XO 1.75 or standard x-86 based hardware.
XO 1.75
In common usage, the XO may be augmented by SD cards and two off the shelf USB devices:
- External hard drive – Allows the server to provide additional storage capabilities.
- Network connector – Allow the server to offer internet access to connected XO's.
This strategy it is simple for a deployment to inventory and maintain school servers.
X-86
For greater flexibility some schools will want to use standard x-86 hardware.
Deliverable
A RPM combined with tested installation instructions necessary to convert a standard XO 1.75 into a School Server.
FUTURE - An image combined with tested installation instruction which can be flashed onto a laptop by deployment support staff. At initial 'power on' the support staff or teacher will be greeted by a simple GUI to do initial configuration.
OS
The school server will be based on OLPC-OS 12.1 on f17
NOTE: Limiting the deliverable to single OS variant meets the base requirements while limiting complexity.
User Interface
Command Line – Command line configuration should be discouraged at all levels. Target users are often not familiar with the linux system administration. Initial setup or fixing a problem with their server is not a good time to introduce system administration skill.
FUTURE - Browser based GUI. – The primary configuration tool will be a browser based GUI. This technology is well understood by developers. Many end uses have familiarity with Browser based setup.
A browser based allow admin from three physical distances:
- On screen. Initial setup and admin of security sensitive services can be limited to on screen.
- On site. Subsequent management of non security sensitive services can be done by a teacher or local admin logging in to the machine.
- Remote. Deployment level support staff can log in and remotely maintain and monitor services.
FUTURE - Remote administration – There are several systema such as CFEngine and puppet which enables remote management. While not immediately required by AU it is highly desirable by large deployment.
Modular design
One of the key design criteria of all successful community based projects is modularity. The original XS suffered because developers took used monolithic design overcome hardware limitations on the XO-1. The improvements in the XO-1.75 allow for the potential inefficiencies of modularity.
Core Server
The core server will contain 5 services which can be extended via extended services.
Service: Network setup
Purpose:
Provider: xs-setup-network
Service: Dynamic Host Configuration Protocol
Purpose: Schoolserver and clients need to be on same subnet.
Provider: dhcpd
Service: Iptables -- Network Address Translation (NAT)
Purpose: Permits all XO’s to access the internet.
Provider: gateway
Service: Internet domain name server
Prupose:
Provider: named
Service: Backup of student work and restore
Purpose:
Provider: idmgr
Service:Jabber server
Purpose: collaboration > 15 clients needs to work.
Provider: ejabberd
Extended Services
Service: Web server
Purpose: Building block for many other extended services
Provider: appache
Service: proxy server and web cache
Purpose: bandwidth, web-filtering, web-monitoring
Provider: squid
Service: OLPC-update
Purpose: OLPC-update is necessary to update the kernel of XO
Provider: rsync
Service: Activity update
Purpose: Enables teachers to easily distribute new or updated activities to their students
Provider: activity updater
Service: Virtual Private Network (VPN)
Purpose: Creating secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities
Provider: open vpn
Future Services
Service: Content filtering (TimM??)
Purpose: age-appropriate surfing, legal compliance, religious risks
Provider: dansguardian
Service: (GeorgeH, Gerald)
Purpose: local distribution/replication of Sugar Activities etc
Provider: pdsh
Service: (JerryV, GeorgeH)
Purpose: Journal submissions to teacher, academic record (homework etc)
Provider: WebDAV
Service: (DSD, GeorgeH)
Purpose: remote upgrading/admin of XS servers (semi-automated)
Provider: Puppet
Service: Book server (SameerV, AlexK, GeorgeH struggling!)
Purpose: compete with Khan Academy?
Provider: pathagar