Add fetch_instance_info_worker_spec

app/workers/activitypub/fetch_instance_info_worker.rb

@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+class ActivityPub::FetchInstanceInfoWorker
+  include Sidekiq::Worker
+  include JsonLdHelper
+  include Redisable
+  include Lockable
+
+  class Error < StandardError; end
+  class GoneError < Error; end
+  class RequestError < Error; end
+
+  SUPPORTED_NOTEINFO_RELS = ['http://nodeinfo.diaspora.software/ns/schema/2.0', 'http://nodeinfo.diaspora.software/ns/schema/2.1'].freeze
+
+  def perform(domain)
+    @instance = Instance.find_by(domain: domain)
+    return if !@instance || @instance.unavailable_domain.present?
+
+    with_redis_lock("instance_info:#{domain}") do
+      link = nodeinfo_link
+      return if link.nil?
+
+      update_info!(link)
+    end
+  end
+
+  private
+
+  def nodeinfo_link
+    nodeinfo = fetch_json("https://#{@instance.domain}/.well-known/nodeinfo")
+    return nil if nodeinfo.nil? || !nodeinfo.key?('links')
+
+    nodeinfo_links = nodeinfo['links']
+    return nil if !nodeinfo_links.is_a?(Array) || nodeinfo_links.blank?
+
+    nodeinfo_link = nodeinfo_links.find { |item| item.key?('rel') && item.key?('href') && SUPPORTED_NOTEINFO_RELS.include?(item['rel']) }
+    return nil if nodeinfo_link.nil? || nodeinfo_link['href'].nil? || !nodeinfo_link['href'].start_with?('http')
+
+    nodeinfo_link['href']
+  end
+
+  def update_info!(url)
+    content = fetch_json(url)
+    return nil if content.nil? || !content.key?('software') || !content['software'].key?('name')
+
+    software = content['software']['name']
+    version = content['software'].key?('version') ? content['software']['version'] : ''
+
+    exists = @instance.instance_info
+    if exists.nil?
+      InstanceInfo.create!(domain: @instance.domain, software: software, version: version, data: content)
+    else
+      exists.software = software
+      exists.version = version
+      exists.data = content
+      exists.save!
+    end
+  end
+
+  def fetch_json(url)
+    build_request(url).perform do |response|
+      if [200, 203].include?(response.code)
+        raise Mastodon::UnexpectedResponseError, response unless response_successful?(response) || response_error_unsalvageable?(response)
+
+        body_to_json(response.body_with_limit)
+      elsif response.code == 410
+        raise ActivityPub::FetchInstanceInfoWorker::GoneError, "#{@instance.domain} is gone from the server"
+      else
+        raise ActivityPub::FetchInstanceInfoWorker::RequestError, "Request for #{@instance.domain} returned HTTP #{response.code}"
+      end
+    end
+  end
+
+  def build_request(url)
+    Request.new(:get, url).add_headers('Accept' => 'application/jrd+json, application/json')
+  end
+end