Add job for setting avatar via XMPP

app/jobs/xmpp_set_avatar_job.rb

@@ -0,0 +1,97 @@
+require 'digest'
+require "image_processing/vips"
+
+class XmppSetAvatarJob < ApplicationJob
+  queue_as :default
+
+  def perform(user:, overwrite: false)
+    @user = user
+
+    unless overwrite
+      current_avatar = get_current_avatar
+      Rails.logger.debug { "User #{user.cn} already has an avatar set. Nothing to do." }
+      return if current_avatar.present?
+    end
+
+    Rails.logger.debug { "Setting XMPP avatar for user #{user.cn}" }
+
+    stanzas = build_xep0084_stanzas
+
+    stanzas.each do |stanza|
+      res = ejabberd.send_stanza {
+        from: user.address, to: user.address, stanza: stanza
+      }
+
+      raise res.inspect if res.status != 200
+    end
+  end
+
+  private
+
+    def ejabberd
+      @ejabberd ||= EjabberdApiClient.new
+    end
+
+    def get_current_avatar
+      res = ejabberd.get_vcard2 @user, "PHOTO", "BINVAL"
+
+      if res.status == 200
+        # VCARD PHOTO/BINVAL prop exists
+        res.body
+      elsif res.status == 400
+        # VCARD or PHOTO/BINVAL prop does not exist
+        nil
+      else
+        # Unexpected error, let job fail
+        raise res.inspect
+      end
+    end
+
+    def process_avatar
+      @user.avatar.blob.open do |file|
+        processed = ImageProcessing::Vips
+          .source(file)
+          .resize_to_fill(256, 256)
+          .convert("png")
+          .call
+        processed.read
+      end
+    end
+
+    def build_xep0084_stanzas
+      img_data    = process_avatar
+      sha1_hash   = Digest::SHA1.hexdigest(img_data)
+      base64_data = Base64.strict_encode64(img_data)
+
+      [
+        """
+<iq type='set' from='#{@user.address}' id='avatar-data-#{rand(101)}'>
+  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
+    <publish node='urn:xmpp:avatar:data'>
+      <item id='#{sha1_hash}'>
+        <data xmlns='urn:xmpp:avatar:data'>#{base64_data}</data>
+      </item>
+    </publish>
+  </pubsub>
+</iq>
+        """.strip,
+        """
+<iq type='set' from='#{@user.address}' id='avatar-metadata-#{rand(101)}'>
+  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
+    <publish node='urn:xmpp:avatar:metadata'>
+      <item id='#{sha1_hash}'>
+        <metadata xmlns='urn:xmpp:avatar:metadata'>
+          <info bytes='#{img_data.size}'
+                id='#{sha1_hash}'
+                height='256'
+                type='image/png'
+                width='256'/>
+        </metadata>
+      </item>
+    </publish>
+  </pubsub>
+</iq>
+        """.strip,
+      ]
+    end
+end

app/services/ejabberd_api_client.rb

@@ -4,16 +4,8 @@ class EjabberdApiClient
   end
 
   def post(endpoint, payload)
-    res = Faraday.post("#{@base_url}/#{endpoint}", payload.to_json,
+    Faraday.post "#{@base_url}/#{endpoint}", payload.to_json,
-                       "Content-Type" => "application/json")
+                 "Content-Type" => "application/json"
-
-    if res.status != 200
-      #TODO Send custom event to Sentry
-      Rails.logger.error "[ejabberd] API request failed:"
-      Rails.logger.error res.body
-    end
-
-    res
   end
 
   #
@@ -24,6 +16,14 @@ class EjabberdApiClient
     post "add_rosteritem", payload
   end
 
+  def send_message(payload)
+    post "send_message", payload
+  end
+
+  def send_stanza(payload)
+    post "send_stanza", payload
+  end
+
   def get_vcard2(user, name, subname)
     payload = {
       user: user.cn, host: user.ou,
@@ -47,8 +47,4 @@ class EjabberdApiClient
     }
     post "private_set", payload
   end
-
-  def send_message(payload)
-    post "send_message", payload
-  end
 end