User:Holt/XS Community Edition/0.1/Project Specifications
School Server - Community Edition 0.1 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.
- Security – XO related security services.
- Content management -- ???
 Reference User
For the purposes of this document, I am taking OLPC-AU as the reference user. As a result this design might not apply in all situations in all deployments. This imposed limitation will make it is easier to design and develop a working reference implementation.
If we use proper modularity it will be relatively straightforward to abstract the design and implementation to meet other use cases.
To reduce inventory and maintenance costs, 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 on them.
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. A school can replace a school server by taking a standard XO and running a single server setup command.
NOTE: Limiting the hardware to XO simplifies the implement and testing process because their fewer possible configurations to deal with. Supporting multiple platform would be a good for a future release.
The final deliverable from the community will be an image which can be flashed onto a laptop by deployment support staff.
At initial server 'power on' the support staff or teacher will be greeted by a simple GUI to do initial configuration.
A single RPM or meta package necessary to convert a standard XO into a School Server should also be possible.
NOTE: Projects tend to emphasize packages while Products tend to emphasize images.
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. Future releases can add additional Operating Systems.
 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.
NOTE: Is is possible or useful to create a Sugar base configuration tool?
 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 components which can be extended via extended services.
Service: Network setup
Service: Dynamic Host Configuration Protocol
Purpose: Schoolserver and clients need to be on same subnet.
Service: Iptables -- Network Address Translation (NAT)
Purpose: Permits all XO’s to access the internet.
Service: Internet domain name server
Purpose: collaboration > 15 clients needs to work.