[feature] Add configuration object to /api/v1/instance response

[tsmethurst]

Mastodon recently added a configuration object that allows clients to see what kind of limits are available on the instance they're connecting to. See: mastodon/mastodon#16485

We should do something similar for GoToSocial to ensure continued mastodon API compatibility.

[igalic]

hrm

why can't that be used to communicate what privacy levels our posts support?

[tsmethurst]

Well, we can use it to communicate features our server supports :) We can (and probably should) also update our nodeinfo with more stuff, cuz right now it's very bare.

[tsmethurst]

For the record, here's the response from the /api/v1/instance endpoint for mastodon.social

{
  "uri": "mastodon.social",
  "title": "Mastodon",
  "short_description": "The original server operated by the Mastodon gGmbH non-profit",
  "description": "",
  "email": "[email protected]",
  "version": "3.5.3",
  "urls": {
    "streaming_api": "wss://mastodon.social"
  },
  "stats": {
    "user_count": 723559,
    "status_count": 36828208,
    "domain_count": 24502
  },
  "thumbnail": "https://files.mastodon.social/site_uploads/files/000/000/001/original/vlcsnap-2018-08-27-16h43m11s127.png",
  "languages": [
    "en"
  ],
  "registrations": true,
  "approval_required": false,
  "invites_enabled": true,
  "configuration": {
    "statuses": {
      "max_characters": 500,
      "max_media_attachments": 4,
      "characters_reserved_per_url": 23
    },
    "media_attachments": {
      "supported_mime_types": [
        "image/jpeg",
        "image/png",
        "image/gif",
        "image/webp",
        "video/webm",
        "video/mp4",
        "video/quicktime",
        "video/ogg",
        "audio/wave",
        "audio/wav",
        "audio/x-wav",
        "audio/x-pn-wave",
        "audio/ogg",
        "audio/vorbis",
        "audio/mpeg",
        "audio/mp3",
        "audio/webm",
        "audio/flac",
        "audio/aac",
        "audio/m4a",
        "audio/x-m4a",
        "audio/mp4",
        "audio/3gpp",
        "video/x-ms-asf"
      ],
      "image_size_limit": 10485760,
      "image_matrix_limit": 16777216,
      "video_size_limit": 41943040,
      "video_frame_rate_limit": 60,
      "video_matrix_limit": 2304000
    },
    "polls": {
      "max_options": 4,
      "max_characters_per_option": 50,
      "min_expiration": 300,
      "max_expiration": 2629746
    }
  },
  "contact_account": {
    "id": "1",
    "username": "Gargron",
    "acct": "Gargron",
    "display_name": "Eugen",
    "locked": false,
    "bot": false,
    "discoverable": true,
    "group": false,
    "created_at": "2016-03-16T00:00:00.000Z",
    "note": "<p>Founder, CEO and lead developer <span class=\"h-card\"><a href=\"https://mastodon.social/@Mastodon\" class=\"u-url mention\">@<span>Mastodon</span></a></span>, Germany.</p>",
    "url": "https://mastodon.social/@Gargron",
    "avatar": "https://files.mastodon.social/accounts/avatars/000/000/001/original/ccb05a778962e171.png",
    "avatar_static": "https://files.mastodon.social/accounts/avatars/000/000/001/original/ccb05a778962e171.png",
    "header": "https://files.mastodon.social/accounts/headers/000/000/001/original/3b91c9965d00888b.jpeg",
    "header_static": "https://files.mastodon.social/accounts/headers/000/000/001/original/3b91c9965d00888b.jpeg",
    "followers_count": 117399,
    "following_count": 299,
    "statuses_count": 71964,
    "last_status_at": "2022-06-25",
    "emojis": [],
    "fields": [
      {
        "name": "Patreon",
        "value": "<a href=\"https://www.patreon.com/mastodon\" target=\"_blank\" rel=\"nofollow noopener noreferrer me\"><span class=\"invisible\">https://www.</span><span class=\"\">patreon.com/mastodon</span><span class=\"invisible\"></span></a>",
        "verified_at": null
      }
    ]
  },
  "rules": [
    {
      "id": "1",
      "text": "Sexually explicit or violent media must be marked as sensitive when posting"
    },
    {
      "id": "2",
      "text": "No racism, sexism, homophobia, transphobia, xenophobia, or casteism"
    },
    {
      "id": "3",
      "text": "No incitement of violence or promotion of violent ideologies"
    },
    {
      "id": "4",
      "text": "No harassment, dogpiling or doxxing of other users"
    },
    {
      "id": "5",
      "text": "No content illegal in Germany"
    },
    {
      "id": "7",
      "text": "Do not share intentionally false or misleading information"
    }
  ]
}