DEV: s/\$redis/Discourse\.redis (#8431)

This commit also adds a rubocop rule to prevent global variables.

app/controllers/application_controller.rb

@@ -768,14 +768,14 @@ class ApplicationController < ActionController::Base
 
     if !SiteSetting.login_required? || (current_user rescue false)
       key = "page_not_found_topics"
-      if @topics_partial = $redis.get(key)
+      if @topics_partial = Discourse.redis.get(key)
         @topics_partial = @topics_partial.html_safe
       else
         category_topic_ids = Category.pluck(:topic_id).compact
         @top_viewed = TopicQuery.new(nil, except_topic_ids: category_topic_ids).list_top_for("monthly").topics.first(10)
         @recent = Topic.includes(:category).where.not(id: category_topic_ids).recent(10)
         @topics_partial = render_to_string partial: '/exceptions/not_found_topics', formats: [:html]
-        $redis.setex(key, 10.minutes, @topics_partial)
+        Discourse.redis.setex(key, 10.minutes, @topics_partial)
       end
     end
 

app/controllers/forums_controller.rb

@@ -9,7 +9,7 @@ class ForumsController < ActionController::Base
   after_action  :add_readonly_header
 
   def status
-    if $shutdown
+    if $shutdown # rubocop:disable Style/GlobalVars
       render plain: "shutting down", status: 500
     else
       render plain: "ok"

app/controllers/session_controller.rb

@@ -409,15 +409,15 @@ class SessionController < ApplicationController
   end
 
   def one_time_password
-    @otp_username = otp_username = $redis.get "otp_#{params[:token]}"
+    @otp_username = otp_username = Discourse.redis.get "otp_#{params[:token]}"
 
     if otp_username && user = User.find_by_username(otp_username)
       if current_user&.username == otp_username
-        $redis.del "otp_#{params[:token]}"
+        Discourse.redis.del "otp_#{params[:token]}"
         return redirect_to path("/")
       elsif request.post?
         log_on_user(user)
-        $redis.del "otp_#{params[:token]}"
+        Discourse.redis.del "otp_#{params[:token]}"
         return redirect_to path("/")
       else
         # Display the form

app/controllers/user_api_keys_controller.rb

@@ -205,7 +205,7 @@ class UserApiKeysController < ApplicationController
     raise Discourse::InvalidAccess unless UserApiKey.allowed_scopes.superset?(Set.new(["one_time_password"]))
 
     otp = SecureRandom.hex
-    $redis.setex "otp_#{otp}", 10.minutes, username
+    Discourse.redis.setex "otp_#{otp}", 10.minutes, username
 
     Base64.encode64(public_key.public_encrypt(otp))
   end

app/controllers/users/associate_accounts_controller.rb

@@ -21,7 +21,7 @@ class Users::AssociateAccountsController < ApplicationController
   # Presents a confirmation screen to the user. Accessed via GET, with no CSRF checks
   def connect
     auth = get_auth_hash
-    $redis.del "#{REDIS_PREFIX}_#{current_user&.id}_#{params[:token]}"
+    Discourse.redis.del "#{REDIS_PREFIX}_#{current_user&.id}_#{params[:token]}"
 
     provider_name = auth.provider
     authenticator = Discourse.enabled_authenticators.find { |a| a.name == provider_name }
@@ -37,7 +37,7 @@ class Users::AssociateAccountsController < ApplicationController
 
   def get_auth_hash
     token = params[:token]
-    json = $redis.get "#{REDIS_PREFIX}_#{current_user&.id}_#{token}"
+    json = Discourse.redis.get "#{REDIS_PREFIX}_#{current_user&.id}_#{token}"
     raise Discourse::NotFound if json.nil?
 
     OmniAuth::AuthHash.new(JSON.parse(json))

app/controllers/users/omniauth_callbacks_controller.rb

@@ -31,7 +31,7 @@ class Users::OmniauthCallbacksController < ApplicationController
     if session.delete(:auth_reconnect) && authenticator.can_connect_existing_user? && current_user
       # Save to redis, with a secret token, then redirect to confirmation screen
       token = SecureRandom.hex
-      $redis.setex "#{Users::AssociateAccountsController::REDIS_PREFIX}_#{current_user.id}_#{token}", 10.minutes, auth.to_json
+      Discourse.redis.setex "#{Users::AssociateAccountsController::REDIS_PREFIX}_#{current_user.id}_#{token}", 10.minutes, auth.to_json
       return redirect_to Discourse.base_uri("/associate/#{token}")
     else
       @auth_result = authenticator.after_authenticate(auth)

app/controllers/webhooks_controller.rb

@@ -119,8 +119,8 @@ class WebhooksController < ActionController::Base
 
     # prevent replay attacks
     key = "mailgun_token_#{token}"
-    return false unless $redis.setnx(key, 1)
-    $redis.expire(key, 10.minutes)
+    return false unless Discourse.redis.setnx(key, 1)
+    Discourse.redis.expire(key, 10.minutes)
 
     # ensure timestamp isn't too far from current time
     return false if (Time.at(timestamp.to_i) - Time.now).abs > 12.hours.to_i