Webhooks: persist data to redis

Save hooks and meetingID mappings to redis and get them back when the
application starts.
Still missing a way to remove old data in case the app loses events (e.g.
a hook for a specific meeting might stay on redis forever if the app
lost the meeting_destroyed event).

labs/bbb-callback/application.coffee

@@ -1,4 +1,6 @@
 config = require("./config")
+Hook = require("./hook")
+MeetingIDMap = require("./meeting_id_map")
 WebHooks = require("./web_hooks")
 WebServer = require("./web_server")
 
@@ -11,5 +13,7 @@ module.exports = class Application
     @webServer = new WebServer()
 
   start: ->
-    @webServer.start(config.server.port)
-    @webHooks.start()
+    Hook.initialize =>
+      MeetingIDMap.initialize =>
+        @webServer.start(config.server.port)
+        @webHooks.start()

labs/bbb-callback/config.coffee

@@ -29,6 +29,13 @@ config.hooks.events = [
   # { channel: "bigbluebutton:from-bbb-apps:meeting", name: "user_registered_message" },
 ]
 
+# Redis
+config.redis = {}
+config.redis.keys = {}
+config.redis.keys.hook = (id) -> "bigbluebutton:webhooks:hook:#{id}"
+config.redis.keys.hooks = "bigbluebutton:webhooks:hooks"
+config.redis.keys.mappings = "bigbluebutton:webhooks:mappings"
+
 config.api = {}
 config.api.responses = {}
 config.api.responses.failure = (key, msg) ->

labs/bbb-callback/hook.coffee

@@ -1,11 +1,14 @@
 _ = require("lodash")
+async = require("async")
+redis = require("redis")
 
+config = require("./config")
 CallbackEmitter = require("./callback_emitter")
 MeetingIDMap = require("./meeting_id_map")
 
 # The database of hooks.
 db = {}
-nextId = 1
+nextID = 1
 
 # The representation of a hook and its properties. Stored in memory and persisted
 # to redis.
@@ -15,22 +18,34 @@ nextId = 1
 # TODO: at some point the queue needs to be cleared, or we need a size limit on it
 module.exports = class Hook
 
-  # @initialize = ->
-  #   # get hooks from redis
-
   constructor: ->
     @id = null
     @callbackURL = null
     @externalMeetingID = null
     @queue = []
     @emitter = null
+    @redisClient = redis.createClient()
 
-  saveSync: ->
-    db[@id] = this
-    db[@id]
+  save: (callback) ->
+    @redisClient.hmset config.redis.keys.hook(@id), @toRedis(), (error, reply) =>
+      console.log "Hook: error saving hook to redis!", error, reply if error?
+      @redisClient.sadd config.redis.keys.hooks, @id, (error, reply) =>
+        console.log "Hook: error saving hookID to the list of hooks!", error, reply if error?
 
-  destroySync: ->
-    Hook.destroySync @id
+        db[@id] = this
+        callback?(error, db[@id])
+
+  destroy: (callback) ->
+    @redisClient.srem config.redis.keys.hooks, @id, (error, reply) =>
+      console.log "Hook: error removing hookID from the list of hooks!", error, reply if error?
+      @redisClient.del config.redis.keys.hook(@id), (error) =>
+        console.log "Hook: error removing hook from redis!", error if error?
+
+        if db[@id]
+          delete db[@id]
+          callback?(error, true)
+        else
+          callback?(error, false)
 
   # Is this a global hook?
   isGlobal: ->
@@ -40,11 +55,6 @@ module.exports = class Hook
   targetMeetingID: ->
     @externalMeetingID
 
-  # mapFromRedis: (redisData) ->
-  #   @callbackURL = redisData?.callbackURL
-  #   @externalMeetingID = redisData?.externalMeetingID
-  #   @id = redisData?.subscriptionID
-
   # Puts a new message in the queue. Will also trigger a processing in the queue so this
   # message might be processed instantly.
   enqueue: (message) ->
@@ -52,6 +62,18 @@ module.exports = class Hook
     @queue.push message
     @_processQueue()
 
+  toRedis: ->
+    {
+      "hookID": @id,
+      "externalMeetingID": @externalMeetingID,
+      "callbackURL": @callbackURL
+    }
+
+  fromRedis: (redisData) ->
+    @callbackURL = redisData?.callbackURL
+    @externalMeetingID = redisData?.externalMeetingID
+    @id = parseInt(redisData?.hookID)
+
   # Gets the first message in the queue and start an emitter to send it. Will only do it
   # if there is no emitter running already and if there is a message in the queue.
   _processQueue: ->
@@ -82,12 +104,10 @@ module.exports = class Hook
       console.log msg
 
       hook = new Hook()
-      hook.id = nextId++
+      hook.id = nextID++
       hook.callbackURL = callbackURL
       hook.externalMeetingID = meetingID
-      hook.saveSync()
-
-      callback?(null, hook)
+      hook.save (error, hook) -> callback?(error, hook)
 
   @removeSubscription = (hookID, callback) ->
     hook = Hook.getSync(hookID)
@@ -96,8 +116,7 @@ module.exports = class Hook
       msg += " for the meeting [#{hook.externalMeetingID}]" if hook.externalMeetingID?
       console.log msg
 
-      hook.destroySync()
-      callback?(null, true)
+      hook.destroy (error, removed) -> callback?(error, removed)
     else
       callback?(null, false)
 
@@ -131,13 +150,6 @@ module.exports = class Hook
     , [])
     arr
 
-  @destroySync = (id) ->
-    if db[id]
-      delete db[id]
-      true
-    else
-      false
-
   @clearSync = ->
     for id of db
       delete db[id]
@@ -147,3 +159,34 @@ module.exports = class Hook
     for id of db
       if db[id].callbackURL is callbackURL
         return db[id]
+
+  @initialize = (callback) ->
+    Hook.resync(callback)
+
+  # Gets all hooks from redis to populate the local database.
+  # Calls `callback()` when done.
+  @resync = (callback) ->
+    client = redis.createClient()
+    tasks = []
+
+    client.smembers config.redis.keys.hooks, (error, hooks) =>
+      console.log "Hook: error getting list of hooks from redis", error if error?
+
+      hooks.forEach (id) =>
+        tasks.push (done) =>
+          client.hgetall config.redis.keys.hook(id), (error, hookData) ->
+            console.log "Hook: error getting information for a hook from redis", error if error?
+
+            if hookData?
+              hook = new Hook()
+              hook.fromRedis hookData
+              hook.save (error, hook) ->
+                nextID = hook.id + 1 if hook.id >= nextID
+                done(null, hook)
+            else
+              done(null, null)
+
+      async.series tasks, (errors, result) ->
+        hooks = _.map(Hook.allSync(), (hook) -> "[#{hook.id}] #{hook.callbackURL}")
+        console.log "Hook: finished resync, hooks registered:", hooks
+        callback?()

labs/bbb-callback/meeting_id_map.coffee

@@ -1,4 +1,7 @@
 _ = require("lodash")
+redis = require("redis")
+
+config = require("./config")
 
 # The database of mappings. Format:
 # { internalMeetingID: externalMeetingID }
@@ -11,12 +14,14 @@ module.exports = class MeetingIDMap
     unless internalMeetingID in _.keys(db)
       db[internalMeetingID] = externalMeetingID
       console.log "MeetingIDMap: added meeting mapping to the list { #{internalMeetingID}: #{db[internalMeetingID]} }"
+      MeetingIDMap.updateRedis()
 
   @removeMapping = (internalMeetingID) ->
     if internalMeetingID in _.keys(db)
       console.log "MeetingIDMap: removing meeting mapping from the list { #{internalMeetingID}: #{db[internalMeetingID]} }"
       delete db[internalMeetingID]
       db[internalMeetingID] = null
+      MeetingIDMap.updateRedis()
 
   @getInternalMeetingID = (externalMeetingID) ->
     for internal, external of db
@@ -26,3 +31,22 @@ module.exports = class MeetingIDMap
 
   @getExternalMeetingID = (internalMeetingID) ->
     db[internalMeetingID]
+
+  @initialize = (callback) ->
+    MeetingIDMap.resync(callback)
+
+  # Gets all mappings from redis to populate the local database.
+  # Calls `callback()` when done.
+  @resync = (callback) ->
+    client = redis.createClient()
+    client.hgetall config.redis.keys.mappings, (error, mappings) =>
+      MeetingIDMap.fromRedis(mappings)
+      callback?(error, mappings)
+
+  @fromRedis = (mappings) ->
+    db = mappings
+
+  @updateRedis = (callback) ->
+    client = redis.createClient()
+    client.hmset config.redis.keys.mappings, db, (error, reply) =>
+      callback?(error)

labs/bbb-callback/web_hooks.coffee

@@ -13,7 +13,6 @@ module.exports = class WebHooks
 
   constructor: ->
     @subscriberEvents = redis.createClient()
-    @client = redis.createClient()
 
     # To map internal and external meeting IDs
     @subscriberMeetings = redis.createClient()
@@ -83,38 +82,3 @@ module.exports = class WebHooks
         console.log "WebHooks: error processing the message", JSON.stringify(message), ":", e
 
     @subscriberMeetings.subscribe config.hooks.meetingsChannel
-
-  # TODO: enable the methods below again when we persist hooks to redis again
-  # # Gets all hooks from redis.
-  # # Calls `callback(errors, result)` when done. `result` is an array of `Hook` objects.
-  # _getHooksFromRedis: (callback) ->
-  #   tasks = []
-  #   @meetings.forEach (meetingID) =>
-  #     console.log "WebHooks: checking hooks for the meeting", meetingID
-  #     tasks.push (done) =>
-
-  #       @client.lrange "meeting:#{meetingID}:subscriptions", 0, -1, (error, subscriptions) =>
-  #         # TODO: treat error
-  #         @_getHooksFromRedisForSubscriptions meetingID, subscriptions, done
-
-  #   async.series tasks, (errors, result) ->
-  #     result = _.flatten result
-  #     console.log "Hooks#_getHooksFromRedis: returning", result
-  #     callback?(errors, result)
-
-  # # Get the hook URLs for a list of subscriptions.
-  # _getHooksFromRedisForSubscriptions: (meetingID, subscriptions, callback) ->
-  #   tasks = []
-  #   subscriptions.forEach (sid, index) =>
-
-  #     tasks.push (done) =>
-  #       @client.hgetall "meeting:#{meetingID}:subscription:#{sid}", (error, redisData) ->
-  #         # TODO: treat error
-  #         console.log "WebHooks: creating hook url for", redisData
-  #         hook = new Hook()
-  #         hook.mapFromRedis redisData
-  #         done null, hook
-
-  #   async.series tasks, (errors, result) ->
-  #     console.log "Hooks#_getHooksFromRedisForSubscriptions: returning", result
-  #     callback?(errors, result)