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== Summary ==
== Summary ==


The requirements:
The design and implementation are tailored by the following intentions:


* Implement the initial server in a [[Platform_Team/Sugar_Network/0.1/Roadmap|short period of time]];
* Implementation should be as lightweight as possible to run all components on restricted hardware like XO laptops;
* Server should work on [[Deployment_Team/Peru/Puno#The_problem|XO laptops]];
* Minimize any maintaining costs as much as possible to use Sugar Network in environments like offline schools where the only maintainers are not IT skilled people;
* System should support synchronisation between distributed servers and provide full featured text search.
* Assume decentralization scheme when Sugar Network nodes might be started on different servers with further online or offline synchronization with the master.


That's why using [[Platform_Team/Sugar_Network/Active_Document|Active Document]] to:
To accomplish above tasks, Sugar Network content is handled by the [[Platform_Team/Active_Document|active-document]] library which uses Xapian to index content and simple filesystem storage (might be changed in the future).


* Server should be as simple/lightweight as possible;
Sugar Network is represented by two major applications to run on Sugar Network node or users side:
* No SQL, just NoSQL;
* Since server should support full featured text search, use Xapian and keep it as a "NoSQL replacement" with storing data directly in files system;
* If server will start serving users from the Internet and current implementation won't manage to handle multiple requests, another implementation might be created.


All [[Sugar_Network/Concept#Resources|resources]] are being represented as Active Document's classes, resource objects as Active Document's objects.
* [[#sugar-network-node|sugar-network-node]], and,
* [[#sugar-network-client|sugar-network-client]].


== Usage ==
In both cases, applications provide RESTful [[Platform_Team/Sugar_Network/API|API]] as the only access point for outer usage. Any end users related functionality implemented in Sugar Network [[Platform_Team/Sugar_Network#Clients|clients]] on top of API providers.
 
== sugar-network-node ==
 
This application provides Sugar Network server functionality. Such functionality served via the Sugar Network [[Platform_Team/Sugar_Network/API|API]].
 
The configuration occurs based on several sources (sorted by applied order):
 
* {{Code|/etc/sugar-network.conf}} system-wide configuration file,
* {{Code|/etc/sugar-network.d}} directory with system-wide configuration files,
* {{Code|~/.config/sugar-network/config}} user-wide configuration file.
* Command-line arguments (configuration names equal to command-line arguments),
 
To get the current configuration, call:
 
sugar-network-node config
 
The major configuration options are:
 
[node]
# path to a directory to place server data
data-root = /var/lib/sugar-network
# hostname to listen for incomming connections and using for publicly visible urls
host = 0.0.0.0
# port number to listen incomming connections
port = 8000
 
Note that `sugar-network-node` needs OpenSSH-5.6 or later to verify users' credentials. If you don't have such version, enable `--trust-users` to disable any verification:
 
[node]
# switch off user credentials check; disabling this option will require OpenSSH-5.6 or later
trust-users = True
 
Assuming that configuration was set properly, use the following commands to manipulate `sugar-network-node` daemon:
 
sugar-network-node start
sugar-network-node stop
sugar-network-node status
 
To run application in the foreground instead of switching to daemon mode, call:
 
sugar-network-node -F start
 
Optionally (next releases might have WebUI as a separate application), it is possible to run [[Platform_Team/Sugar_Network/Web_UI|Web UI]] client from the same process if the following configuration options were set:


=== Public instance ===
[webui]
# start web application to serve Sugar Network content
webui = True
# hostname to bind
webui-host = 0.0.0.0
# address to listen for Web clients
webui-port = 5000


Testing instance is {{Code|api.network.sugarlabs.org}}. It support HTTPS connections using StartSSL certificate.
== sugar-network-client ==


Add the {{Code|18.85.44.120 api.network.sugarlabs.org}} IP to {{Code|/etc/hosts}} file and use http://api.network.sugarlabs.org:8000 as connection url.
This is a client side application. The reasons to have such client application (instead of direct using of server API) are the following:


=== Local instance ===
* Provide access to local Sugar Network data (providing [[Platform_Team/Sugar_Network/API|API]] from the localhost), e.g., from remote devices;
* Being not connected to a server, users might create postponed changes in Sugar Network content, they will be applied to a server right after getting connected;
* Having locally provided API as a proxy to a server, it is the only way (for now) to be authenticated on the server;
* Provide features that can't served from a servers, e.g., launching activities;
* Keeping in mind two previous points, run [[Platform_Team/Sugar_Network/Web_UI|Web UI]] and [[Sugar_Network/Contributor_Hub|Contributor Hub]] clients locally.


Attach [http://download.sugarlabs.org/packages/Server:/Factory/ Server:Factory] repository. For Ubuntu repositories, download GPG key:
The configuration occurs based on several sources (sorted by applied order):


wget -qO- <REPO-URL>/Release.key | sudo apt-key add -
* Command-line arguments (configuration names equal to command-line arguments),
* {{Code|/etc/sweets.conf}} system-wide configuration file,
* {{Code|/etc/sweets.d}} directory with system-wide configuration files,
* {{Code|~/.config/sweets/config}} user-wide configuration file,
* {{Code|~/.sugar/''current-profile''/sweets.conf}} configuration specific to a Sugar profile, this configuration file is being created by Sugar Integration code in Sugar and better to avoid setting these options directly.


And install {{Code|sugar-network-server}} package.
To get the current configuration, call:


To see current configuration:
sugar-network-client config


sugar-network-server config
The major configuration options are:


Default configuration is (tweak {{Code|/etc/sugar-network-server.conf}} file to change it):
[client]
# url to connect to Sugar Network server API
api-url = http://api-testing.network.sugarlabs.org
# port number to listen for incomming connections from IPC clients
ipc-port = 5001
# path to Contributor Hub site directory to serve from /hub location for IPC
# clients to workaround lack of CORS for SSE while using Hub from file:// url
hub-root = /usr/share/sugar-network/hub
[webui]
# start web application to serve Sugar Network content
webui = False
# hostname to bind
webui-host = 127.0.0.1
# address to listen for Web clients
webui-port = 5000


* server listens {{Code|0.0.0.0:8000}} address;
[[Sugar_Network/Contributor_Hub|Contributor Hub]] is a pure JavaScript application, i.e., it is possible to open it in a Web browser from local files system. But since Server-sent events doesn't support Cross-origin resource sharing, Contributor Hub has to be provided from the same locations as API, here, from {{Code|/hub}} path:
* database in {{Code|/var/lib/sugar-network}} directory;
* log directory in {{Code|/var/log/sugar-network}}.


To start server:
http://localhost:5000/hub


/etc/init.d/sugar-network-server start
== Usage ==


To simplify testing, untar example [http://people.sugarlabs.org/~alsroot/db.tar.xz db data] to {{Code|/var/lib/sugar-network}} and restart server (it will take some time to create indexes).
Depending on use-case, follow one of existing [[Deployment_Platform#Deployment_scenarios|usage scenarios]].


== Features ==
== Sources ==


=== Collecting usage statics ===
Clone sources from Git repository:


Server will accept [[Platform_Team/Usage_Statistics|usage statistics]] from clients (and, for master server, from nodes) and will keep them in {{Code|--stats-root}} directory.
git clone git://git.sugarlabs.org/network/network.git --recurse-submodules


== Todo ==
== See Also ==


* Network notifications framework to, e.g., let client cache resources and refetch them only on updates. Reuse existing or implement something similar to Facebook's [http://developers.facebook.com/docs/reference/api/realtime/ real-time updates].
* Sugar Network [[Platform_Team/Sugar_Network/API|API]].
* Support collaborative work on Wiki pages for different resources.
* Distribution [[Sugar_Network#Try_it|options]].
* Sugar Network [[Platform_Team/Sugar_Network#Clients|clients]].


== Getting involved ==
== Getting involved ==


{{:Sugar_Network/Feedback}}
{{:Sugar_Network/Feedback}}
* [[Sugar Server Kit]]'s [http://git.sugarlabs.org/server Gitorious project] for server side libraries.
* Sugar Network's [http://git.sugarlabs.org/network Gitorious projects] itself.
Retrieved from "https://wiki.sugarlabs.org/go/Platform_Team/Sugar_Network/Implementation"