debianize-mobilizon/docs/contribute/activity_pub.md
Thomas Citharel 39b7a5b948
Improve JSON-LD representation for Address and add it to the docs
Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2019-12-16 11:47:57 +01:00

171 lines
5.3 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Federation
## ActivityPub
Mobilizon uses [ActivityPub](http://activitypub.rocks/) to federate content between instances. It only supports the server-to-server part of [the ActivityPub spec](https://www.w3.org/TR/activitypub/).
It implements the [HTTP signatures spec](https://tools.ietf.org/html/draft-cavage-http-signatures-12) for authentication of inbox deliveries, but doesn't implement Linked Data Signatures for forwarded payloads, and instead fetches content when needed.
To match usernames to actors, Mobilizon uses [WebFinger](https://tools.ietf.org/html/rfc7033).
## Instance subscriptions
Instances subscribe to each other through an internal actor named `relay@instance.tld` that publishes (through `Announce`) every created content to it's followers. Each content creation share is saved so that updates and deletes are correctly sent to every relay subscriber.
## Activities
Supported Activity | Supported Object
------------ | -------------
`Accept` | `Follow`, `Join`
`Announce` | `Object`
`Create` | `Note`, `Event`
`Delete` | `Object`
`Flag` | `Object`
`Follow` | `Object`
`Reject` | `Follow`, `Join`
`Remove` | `Note`, `Event`
`Undo` | `Announce`, `Follow`
`Update` | `Object`
## Extensions
### Event
The vocabulary for Event is based on [the Event object in ActivityStreams](https://www.w3.org/TR/activitystreams-vocabulary/#dfn-event), extended with :
* the [Event Schema](https://schema.org/Event) from Schema.org
* some properties from [iCalendar](https://tools.ietf.org/html/rfc5545), such as `ical:status` (see [this issue](https://framagit.org/framasoft/mobilizon/issues/320))
The following properties are added.
#### repliesModeration
Disabling replies is [an ongoing issue with ActivityPub](https://github.com/w3c/activitypub/issues/319) so we use a temporary property.
See [the corresponding issue](https://framagit.org/framasoft/mobilizon/issues/321).
Accepted values: `allow_all`, `closed`, `moderated` (not used at the moment)
!!! info
We also support PeerTube's `commentEnabled` property as a fallback. It is set to `true` only when `repliesModeration` is equal to `allow_all`.
Example:
```json
{
"@context": [
"...",
{
"mz": "https://joinmobilizon.org/ns#",
"pt": "https://joinpeertube.org/ns#",
"repliesModerationOption": {
"@id": "mz:repliesModerationOption",
"@type": "mz:repliesModerationOptionType"
},
"repliesModerationOptionType": {
"@id": "mz:repliesModerationOptionType",
"@type": "rdfs:Class"
},
"commentsEnabled": {
"@id": "pt:commentsEnabled",
"@type": "sc:Boolean"
}
}
],
"...": "...",
"repliesModerationOption": "allow_all",
"commentsEnabled": true,
"type": "Event",
"url": "http://mobilizon1.com/events/8cf76e9f-c426-4912-9cd6-c7030b969611"
}
```
#### joinMode
Indicator of how new members may be able to join.
See [the corresponding issue](https://framagit.org/framasoft/mobilizon/issues/321).
Accepted values: `free`, `restricted`, `invite` (not used at the moment)
Example:
```json
{
"@context": [
"...",
{
"mz": "https://joinmobilizon.org/ns#",
"joinMode": {
"@id": "mz:joinMode",
"@type": "mz:joinModeType"
},
"joinModeType": {
"@id": "mz:joinModeType",
"@type": "rdfs:Class"
}
}
],
"...": "...",
"joinMode": "restricted",
"type": "Event",
"url": "http://mobilizon1.com/events/8cf76e9f-c426-4912-9cd6-c7030b969611"
}
```
#### location
We use Schema.org's `location` property on `Event`.
[The ActivityStream vocabulary to represent places](https://www.w3.org/TR/activitystreams-vocabulary/#places) is quite limited so instead of using `Place` from ActivityStreams we use `Place` from Schema.org.
A [Schema.org `Place` type](https://schema.org/Place) has [an `address` property](https://schema.org/address), which we assume to be [of `PostalAddress` type](https://schema.org/PostalAddress) and [a `geo` property](https://schema.org/geo), which is assumed to be of [`GeoCoordinates` type](https://schema.org/GeoCoordinates).
```json
{
"@context": [
"...",
{
"GeoCoordinates": "sc:GeoCoordinates",
"Place": "sc:Place",
"PostalAddress": "sc:PostalAddress",
"address": {
"@id": "sc:address",
"@type": "sc:PostalAddress"
},
"addressCountry": "sc:addressCountry",
"addressLocality": "sc:addressLocality",
"addressRegion": "sc:addressRegion",
"geo": {
"@id": "sc:geo",
"@type": "sc:GeoCoordinates"
},
"location": {
"@id": "sc:location",
"@type": "sc:Place"
},
"postalCode": "sc:postalCode",
"sc": "http://schema.org#",
"streetAddress": "sc:streetAddress",
}
],
"id": "http://mobilizon2.com/events/945f350d-a3e6-4bcd-9bf2-0bd2e4d353c5",
"location": {
"address": {
"addressCountry": "France",
"addressLocality": "Lyon",
"addressRegion": "Auvergne-Rhône-Alpes",
"postalCode": "69007",
"streetAddress": "10 Rue Jangot",
"type": "PostalAddress"
},
"geo": {
"latitude": 4.8425657,
"longitude": 45.7517141,
"type": "GeoCoordinates"
},
"id": "http://mobilizon2.com/address/bdf7fb53-7177-46f3-8fb3-93c25a802522",
"name": "10 Rue Jangot",
"type": "Place"
},
"type": "Event"
}
```