paragliding

Reasoning

I chose to use globalsign/mgo because it had solid documentation and was not as rough around the edges as the official API for MongoDB.

I tried to have concurrency in mind while designing this system, hence I tried to use channels and non-blocking actions were I could.

About

An online service that will allow users to browse information about IGC files. IGC is an international file format for soaring track files that are used by paragliders and gliders.

The service will store IGC files metadata in a NoSQL Database (persistent storage). The system will generate events, which can be subscribed to using webhooks, and it will monitor for new events happening from the outside services.

Clocktrigger

Link to the paragliding-clocktrigger which is deployed on open-stack.

IGC-Tracks API

GET /paragliding/api

Returns metadata about the service formatted as a json struct.

POST /paragliding/api/track

Register a track. A single track can only be registered once.

Request

{
  "url": "<url>"
}

<url> represents a normal URL, that would work in a browser, eg: http://skypolaris.org/wp-content/uploads/IGS%20Files/Madrid%20to%20Jerez.igc.

Response

{
  "id": "<id>"
}

The returned <id> will be a unique identifier for the posted track.

GET /paragliding/api/track

Returns all the ids of all registered tracks.

[<id1>, <id2>, ...]

GET /paragliding/api/track/<id>

Returns metadata about a specific track. <id> is a valid track id which was returned on insertion using POST.

{
"H_date": <date from File Header, H-record>,
"pilot": <pilot>,
"glider": <glider>,
"glider_id": <glider_id>,
"track_length": <calculated total track length>,
"track_src_url": <the original URL used to upload the track, ie. the URL used with POST>
}

GET /paragliding/api/track/<id>/<field>

Possible <field>-values:

• pilot
• glider
• glider_id
• track_length
• H_date
• track_src_url

The response will be formatted as plain text.

Ticker API

GET /paragliding/api/ticker/latest

Returns the timestamp (formatted as specified in RFC3339) of the last added track as plain text.

GET /paragliding/api/ticker/

Returns a report of the oldest tracks added.

{
"t_latest": <latest added timestamp>,
"t_start": <the first timestamp of the added track>, this will be the oldest track recorded
"t_stop": <the last timestamp of the added track>, this might equal to t_latest if there are no more tracks left
"tracks": [<id1>, <id2>, ...],
"processing": <time in ms of how long it took to process the request>
}

GET /paragliding/api/ticker/<timestamp>

Returns a report of the added tracks after a certain timestamp (formatted as specified in RFC3339).

{
"t_latest": <latest added timestamp of the entire collection>,
"t_start": <the first timestamp of the added track>, this will be higher than the parameter provided in the query
"t_stop": <the last timestamp of the added track>, this might equal to t_latest if there are no more tracks left
"tracks": [<id1>, <id2>, ...],
"processing": <time in ms of how long it took to process the request>
}

Webhook API

POST /paragliding/api/webhook/new_track

Register a webhook which will be notified when new tracks are added to the service.

Request

{
"webhookURL": <url to the webhook>,
"minTriggerValue": <minimum added tracks before a notification is sent>
}

Response

The response will be the unique <webhook_id> for the current webhook, sent as a plain text response.

GET /paragliding/api/webhook/new_track/<webhook_id>

Get details about the webhook with the given <webhook_id>.

DELETE /paragliding/api/webhook/new_track/<webhook_id>

Delete the webhook subscription specified by the given <webhook_id>.