Chat Federation (and a lot more) WIP:

Note: websocket s2s is not working yet, still WIP.

New Features

* Chat Federation:
  * You can now connect to a remote chat with your local account.
  * This remote connection is done using a custom implementation of [XEP-0468: WebSocket S2S](https://xmpp.org/extensions/xep-0468.html), using some specific discovering method (so that it will work without any DNS configuration).

Minor changes and fixes

* Possibility to debug Prosody in development environments.
* Using process.spawn instead of process.exec to launch Prosody (safer, and more optimal).
* Prosody AppImage: fix path mapping: we only map necessary /etc/ subdir, so that the AppImage can access to /etc/resolv.conf, /etc/hosts, ...
* Prosody AppImage: hidden debug mode to disable lua-unbound, that seems broken in some docker dev environments.

server/lib/federation/storage.ts

@@ -1,5 +1,5 @@
 import type { RegisterServerOptions, MVideoFullLight, MVideoAP, Video, MVideoThumbnail } from '@peertube/peertube-types'
-import type { LiveChatJSONLDAttribute } from './types'
+import type { LiveChatJSONLDAttribute, LiveChatJSONLDS2SLink, LiveChatJSONLDPeertubeWSS2SLink } from './types'
 import { sanitizePeertubeLiveChatInfos } from './sanitize'
 import { URL } from 'url'
 import * as fs from 'fs'
@@ -97,6 +97,60 @@ async function getVideoLiveChatInfos (
   return r
 }
 
+/**
+ * When receiving livechat information for remote servers, we store some information
+ * about remote server capatibilities: has it s2s enabled? can it proxify s2s in Peertube?
+ * These information can then be read by Prosody module mod_s2s_peertubelivechat.
+ *
+ * We simply store the more recent informations. Indeed, it should be consistent between videos.
+ * @param options server optiosn
+ * @param liveChatInfos livechat stored data
+ */
+async function storeRemoteServerInfos (
+  options: RegisterServerOptions,
+  liveChatInfos: LiveChatJSONLDAttribute
+): Promise<void> {
+  if (!liveChatInfos) { return }
+
+  const logger = options.peertubeHelpers.logger
+
+  const roomJID = liveChatInfos.jid
+  const host = roomJID.split('@')[1]
+  if (!host) {
+    logger.error(`Room JID seems not correct, no host: ${roomJID}`)
+    return
+  }
+  if (host.includes('..')) {
+    logger.error(`Room host seems not correct, contains ..: ${host}`)
+    return
+  }
+  const dir = path.resolve(
+    options.peertubeHelpers.plugin.getDataDirectoryPath(),
+    'serverInfos',
+    host
+  )
+  const s2sFilePath = path.resolve(dir, 's2s')
+  const wsS2SFilePath = path.resolve(dir, 'ws-s2s')
+
+  const s2sLink = liveChatInfos.links.find(v => v.type === 'xmpp-s2s')
+  if (s2sLink) {
+    await _store(options, s2sFilePath, {
+      host: (s2sLink as LiveChatJSONLDS2SLink).host,
+      port: (s2sLink as LiveChatJSONLDS2SLink).port
+    })
+  } else {
+    await _del(options, s2sFilePath)
+  }
+  const wsS2SLink = liveChatInfos.links.find(v => v.type === 'xmpp-peertube-livechat-ws-s2s')
+  if (wsS2SLink) {
+    await _store(options, wsS2SFilePath, {
+      url: (wsS2SLink as LiveChatJSONLDPeertubeWSS2SLink).url
+    })
+  } else {
+    await _del(options, wsS2SFilePath)
+  }
+}
+
 async function _getFilePath (
   options: RegisterServerOptions,
   remote: boolean,
@@ -152,13 +206,22 @@ async function _del (options: RegisterServerOptions, filePath: string): Promise<
 async function _store (options: RegisterServerOptions, filePath: string, content: any): Promise<void> {
   const logger = options.peertubeHelpers.logger
   try {
+    const jsonContent = JSON.stringify(content)
     if (!fs.existsSync(filePath)) {
       const dir = path.dirname(filePath)
       if (!fs.existsSync(dir)) {
         fs.mkdirSync(dir, { recursive: true })
       }
+    } else {
+      // only write if the content is different
+      try {
+        const currentJSONContent = await fs.promises.readFile(filePath, {
+          encoding: 'utf-8'
+        })
+        if (currentJSONContent === jsonContent) { return }
+      } catch (_err) {}
     }
-    await fs.promises.writeFile(filePath, JSON.stringify(content), {
+    await fs.promises.writeFile(filePath, jsonContent, {
       encoding: 'utf-8'
     })
   } catch (err) {
@@ -182,7 +245,16 @@ async function _get (options: RegisterServerOptions, filePath: string): Promise<
   }
 }
 
+function getRemoteServerInfosDir (options: RegisterServerOptions): string {
+  return path.resolve(
+    options.peertubeHelpers.plugin.getDataDirectoryPath(),
+    'serverInfos'
+  )
+}
+
 export {
   storeVideoLiveChatInfos,
-  getVideoLiveChatInfos
+  storeRemoteServerInfos,
+  getVideoLiveChatInfos,
+  getRemoteServerInfosDir
 }