User:Holt/XS Community Edition/0.2/Project Specifications
School Server - Community Edition 0.2 Project Specifications Contents [hide]
Contents
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.
- Security – XO related security services. - Future
- Content management - FUTURE
Reference User
The XS-CE has two different types of reference user:
- Highly 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 fuctional reference implementation.
Hardware
The target hardware for the school server will be recent XO laptop. Due to hardware limitations on early XO's, design and implementation of a fully functional server becomes difficult.
In common usage, the XO may be augmented by 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.
Using this strategy it is simple for a deployment to inventory and maintain school servers.
NOTE: Limiting the hardware to XO simplifies the implement and testing process because their fewer possible configurations to deal with.
Deliverable
A RPM combined with tested installation instructions necessary to convert a standard XO 1.75 into a School Server should also be possible.
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
To keep things simple and consistent the school server will run the same OS as the classroom laptops. Both teachers and support staff will already be familiar with the system.
NOTE: Limiting the deliverable to single OS variant meets the requirement to work on a XO 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.
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 proximity 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.
Remote automation – There are several system such as CFEngine and puppet which enable remote management. While not immediately required by AU it is highly desirable by large deployment. - FUTURE
Modular Design
One of the key design criteria of all successful community based projects is modularity. The original XS suffered because Wad and Martin 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.
TODO
The core server will contain 3 components: 1. Initial setup and configuration. 2. GUI framework. 3. Core services with GUI panels. The core server will be extended via extended services. Initial Setup Service: Network setup Purpose: Provider: xs-setup-network GUI Framework The GUI permits permits configuration of the network interfaces: Already existing network and internet gateway Choose fixed ip and gateway use dhcp automatic assignment Establish a gateway to the internet, setup WAN and LAN: Use dhcp to setup WAN Manually setup WAN address, gateway, dns Use either of the above methods to set up LAN It permits enabling and disabling of services -- supported and enabled for this release are dhcp, iptables/gateway, named, ejabberd. Core Services 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:Jabber server (AnnaS) Purpose: collaboration > 15 clients needs to work Provider: ejabberd Extended Services Service: proxy server and web cache (XavierC) Purpose: bandwidth, web-filtering, web-monitoring Provider: squid Service: Content filtering (TimM??) Purpose: age-appropriate surfing, legal compliance, religious risks Provider: dansguardian Service: Backup of student work and restore (JerryV, SameerV, GeorgeH) Purpose: also for stats/metrics, with incumbent surveillance risks Provider: idmgr 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: (GeorgeH, GeraldA) Purpose: local distribution/replication of Sugar Activities etc Provider: pdsh Service: Book server (SameerV, AlexK, GeorgeH struggling!) Purpose: compete with Khan Academy? Provider: pathagar
