Features/Transfer to many options

Proposal for a client-initiated journal transfer (1-to-N feature)

Workflow

The server XO would make its shares available via WebDAV, running in the context of "httpd" service.
The client XO would connect to the server XO via its browser.
Therafter, "Browse" would take over.

Details

Setting up WebDAV on a server XO.
- Install package "httpd".
- Generate openssl "server.crt" and "server.key".

       cd /etc/ssl/certs/
       sudo openssl req -new -newkey rsa:1024 -days 365 -nodes -x509 -keyout ssl.key -out ssl.crt

- Configure "/etc/httpd/conf.d/ssl.conf" to setup the WebDAV share. Sample file : media:ssl.conf
  - Firstly, this sets up the paths "SSLCertificateFile" and "SSLCertificateKeyFile", which are required for HTTPS over SSL.
  - Secondly, sets up "/var/www/web1/web" as the "webdav" folder. In other words, whetever entries are present in this folder, will be made available for the client XOs.
- Generate authentication file for the webdav folder. These user-password credentials will be asked whenever a client tries to access the webdav folder. For example, the following list of commands sets "test" as the user, and "olpc" as the password.

       sudo htpasswd -c /var/www/web1/passwd.dav test
       New password:  <olpc>
       Re-type new password:  <olpc> 
       Adding password for user test

- Start service "httd".
- ALL THESE STEPS WOULD BE DONE AS PART OF OOB STAGE.

[User-Workflow] Exporting Data to WebDav, on a server XO.
- Sascha's JournalToWebDAV workflow.
  - step 1
  - step 2
  - step 3
  - step 4
- Alternatively,
  - Add "Share" listview in the bottom panel-tray; that would make a total of 4 types of listview - Journal, Documents, Mounted-Drives, Share.
  - "Share" would follow all the schematics of "Documents" type. After all, "Share" is just a folder in the filesystem (like "Documents").
  - The corresponding folder is "/var/www/web1/web" (as configured in "/etc/httpd/conf.d/ssl.conf").
  - All entries in the "Share" folder would be available to client XOs.

[Code-Requirements] Exporting Data to WebDav, on a server XO.
- Sascha has already coded the first alternative.
- For the second alternative, "Share" listview needs to be added on the lines of "Documents" listview. Code-reuse should be done as much as possible. Ideally, there should just be a difference of the "folder-path".

[User-Workflow] Client XO wishes to access the share of Server XO.
- Navigates to the "Neighborhood" view.
- Hovers over the "Server" buddy.
- The popup appears, which has a new entry "Access Share" (in addition to "Make Friend").
- Clicks on "Access Share".
- The "Browser" activity opens, with the url pointing to the "Server" buddy's webdav share.
- Thereafter, client may navigate the webdav directory hierarchy, or download files (all of which is already built in the "Browse" activity). Most importantly, there is the "Keep Link" feature in "Browse", which nicely downloads the webdav-entry, and promptly saves it in the "Journal" - something that happens in the "Send To" feature as well.

[Code-Requirements] Client XO wishes to access the share of Server XO.
- Mapping a neighborhood-buddy to its IP Address
  - Luckily, in the method "def __buddy_updated_cb(self, account, contact_id, properties):" in "jarabe/model/neighborhood.py", there is the "properties['ip4-address']", which contains the IP address of the buddy. All that is needed is to persist it in the "BaseBuddyModel" in "jarabe/model/buddy.py".
  - When the client clicks on "Access Share" on the buddy, this IP Address can be easily retreived, and the URI formed "https://<IP Address>/webdav"
- Opening up the server's webdav
  - The generated URI would be passed to the "Browse" activity; and thereafter, "Browse" would take over.
- A minor query, regarding the last point, has been posted at http://lists.sugarlabs.org/archive/sugar-devel/2012-April/036425.html. (For resolving this, some additional code may have to be written, but that is something perfectly doable. However, currently awaiting a reply, to see if the code for this already exists :-) ).

SCREENSHOTS

SERVER has initially empty "Shares" icon in bottom tray.

- [To be decided] Is "Shares" the correct terminology ?
- [To be decided] Icon for "Shares".

CLIENT clicks on "Access Shares" in Neighborhood View.

CLIENT enters the SERVER username and password in the opened "Browse" instance.

CLIENT sees nothing shared as the SERVER has not shared anything yet.

SERVER copies data to "Shares".

SERVER now has some entries in "Shares" directory.

CLIENT clicks the refresh button in "Browse".

CLIENT is now able to see the SERVER's "Shares" listing.

CLIENT right clicks on the entry that she wishes to download and selects "Keep Link".

CLIENT Download completed.

CLIENT downloaded entry in Journal.

[ARCHIVE] Possible options

In a server-initiated operation, the server is responsible for adequate delivery to all the clients, whatever the number may be. In a client-initiated operation, each client is responsible for herself only.

Option	Server-Initiated / Client-Initiated	Secure Data Transfer	Peer to Peer Support (Gabble/Salut)
Looping over "Send To"	Server-Initiated		Yes/Yes
Sascha's JournalToWebDAV	Client-Initiated
Each XO acts as an independent WebDAV server; client uses browser	Client-Initiated	Yes (HTTPS over SSL)	/Yes